Remove dfr from dataframe commands (#5760)

* input and output tests

* input and output types for dfr

* expression converter

* remove deprecated command

* correct expressions

* cargo clippy

* identifier for ls

* cargo clippy

* type for head and tail expression

* modify full cell path if block

crates/nu-cli/src/menus/help_completions.rs

@@ -87,7 +87,7 @@ impl NuHelpCompleter {
 
                 let extra: Vec<String> = examples
                     .iter()
-                    .map(|example| example.example.to_string())
+                    .map(|example| example.example.replace('\n', "\r\n"))
                     .collect();
 
                 Suggestion {

crates/nu-command/src/dataframe/eager/append.rs

@@ -2,7 +2,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 use super::super::values::{Axis, Column, NuDataFrame};
@@ -12,7 +12,7 @@ pub struct AppendDF;
 
 impl Command for AppendDF {
     fn name(&self) -> &str {
-        "dfr append"
+        "append"
     }
 
     fn usage(&self) -> &str {
@@ -30,8 +30,8 @@ impl Command for AppendDF {
         vec![
             Example {
                 description: "Appends a dataframe as new columns",
-                example: r#"let a = ([[a b]; [1 2] [3 4]] | dfr to-df);
-    $a | dfr append $a"#,
+                example: r#"let a = ([[a b]; [1 2] [3 4]] | to-df);
+    $a | append $a"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -57,8 +57,8 @@ impl Command for AppendDF {
             },
             Example {
                 description: "Appends a dataframe merging at the end of columns",
-                example: r#"let a = ([[a b]; [1 2] [3 4]] | dfr to-df);
-    $a | dfr append $a --col"#,
+                example: r#"let a = ([[a b]; [1 2] [3 4]] | to-df);
+    $a | append $a --col"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -87,6 +87,14 @@ impl Command for AppendDF {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/column.rs

@@ -1,87 +0,0 @@
-use nu_engine::CallExt;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Value,
-};
-
-use super::super::values::{Column, NuDataFrame};
-
-#[derive(Clone)]
-pub struct ColumnDF;
-
-impl Command for ColumnDF {
-    fn name(&self) -> &str {
-        "dfr column"
-    }
-
-    fn usage(&self) -> &str {
-        "Returns the selected column"
-    }
-
-    fn signature(&self) -> Signature {
-        Signature::build(self.name())
-            .required("column", SyntaxShape::String, "column name")
-            .category(Category::Custom("dataframe".into()))
-    }
-
-    fn examples(&self) -> Vec<Example> {
-        vec![Example {
-            description: "Returns the selected column as series",
-            example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr column a",
-            result: Some(
-                NuDataFrame::try_from_columns(vec![Column::new(
-                    "a".to_string(),
-                    vec![Value::test_int(1), Value::test_int(3)],
-                )])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        }]
-    }
-
-    fn run(
-        &self,
-        engine_state: &EngineState,
-        stack: &mut Stack,
-        call: &Call,
-        input: PipelineData,
-    ) -> Result<PipelineData, ShellError> {
-        command(engine_state, stack, call, input)
-    }
-}
-
-fn command(
-    engine_state: &EngineState,
-    stack: &mut Stack,
-    call: &Call,
-    input: PipelineData,
-) -> Result<PipelineData, ShellError> {
-    let column: Spanned<String> = call.req(engine_state, stack, 0)?;
-
-    let df = NuDataFrame::try_from_pipeline(input, call.head)?;
-
-    let res = df.as_ref().column(&column.item).map_err(|e| {
-        ShellError::GenericError(
-            "Error selecting column".into(),
-            e.to_string(),
-            Some(column.span),
-            None,
-            Vec::new(),
-        )
-    })?;
-
-    NuDataFrame::try_from_series(vec![res.clone()], call.head)
-        .map(|df| PipelineData::Value(NuDataFrame::into_value(df, call.head), None))
-}
-
-#[cfg(test)]
-mod test {
-    use super::super::super::test_dataframe::test_dataframe;
-    use super::*;
-
-    #[test]
-    fn test_examples() {
-        test_dataframe(vec![Box::new(ColumnDF {})])
-    }
-}

crates/nu-command/src/dataframe/eager/command.rs

@@ -1,42 +0,0 @@
-use nu_engine::get_full_help;
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, IntoPipelineData, PipelineData, ShellError, Signature, Value,
-};
-
-#[derive(Clone)]
-pub struct Dataframe;
-
-impl Command for Dataframe {
-    fn name(&self) -> &str {
-        "dfr"
-    }
-
-    fn usage(&self) -> &str {
-        "Dataframe commands"
-    }
-
-    fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("dataframe".into()))
-    }
-
-    fn run(
-        &self,
-        engine_state: &EngineState,
-        stack: &mut Stack,
-        call: &Call,
-        _input: PipelineData,
-    ) -> Result<PipelineData, ShellError> {
-        Ok(Value::String {
-            val: get_full_help(
-                &Dataframe.signature(),
-                &Dataframe.examples(),
-                engine_state,
-                stack,
-            ),
-            span: call.head,
-        }
-        .into_pipeline_data())
-    }
-}

crates/nu-command/src/dataframe/eager/describe.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::{
     chunked_array::ChunkedArray,
@@ -19,7 +19,7 @@ pub struct DescribeDF;
 
 impl Command for DescribeDF {
     fn name(&self) -> &str {
-        "dfr describe"
+        "describe"
     }
 
     fn usage(&self) -> &str {
@@ -40,7 +40,7 @@ impl Command for DescribeDF {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "dataframe description",
-            example: "[[a b]; [1 1] [1 1]] | dfr to-df | dfr describe",
+            example: "[[a b]; [1 1] [1 1]] | to-df | describe",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new(
@@ -95,6 +95,14 @@ impl Command for DescribeDF {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/drop.rs

@@ -2,7 +2,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 use super::super::values::utils::convert_columns;
@@ -13,7 +13,7 @@ pub struct DropDF;
 
 impl Command for DropDF {
     fn name(&self) -> &str {
-        "dfr drop"
+        "drop"
     }
 
     fn usage(&self) -> &str {
@@ -29,7 +29,7 @@ impl Command for DropDF {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "drop column a",
-            example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr drop a",
+            example: "[[a b]; [1 2] [3 4]] | to-df | drop a",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "b".to_string(),
@@ -41,6 +41,14 @@ impl Command for DropDF {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/drop_duplicates.rs

@@ -2,7 +2,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::UniqueKeepStrategy;
 
@@ -14,7 +14,7 @@ pub struct DropDuplicates;
 
 impl Command for DropDuplicates {
     fn name(&self) -> &str {
-        "dfr drop-duplicates"
+        "drop-duplicates"
     }
 
     fn usage(&self) -> &str {
@@ -40,7 +40,7 @@ impl Command for DropDuplicates {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "drop duplicates",
-            example: "[[a b]; [1 2] [3 4] [1 2]] | dfr to-df | dfr drop-duplicates",
+            example: "[[a b]; [1 2] [3 4] [1 2]] | to-df | drop-duplicates",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new(
@@ -58,6 +58,14 @@ impl Command for DropDuplicates {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/drop_nulls.rs

@@ -2,7 +2,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 use super::super::values::utils::convert_columns_string;
@@ -13,7 +13,7 @@ pub struct DropNulls;
 
 impl Command for DropNulls {
     fn name(&self) -> &str {
-        "dfr drop-nulls"
+        "drop-nulls"
     }
 
     fn usage(&self) -> &str {
@@ -34,10 +34,10 @@ impl Command for DropNulls {
         vec![
             Example {
                 description: "drop null values in dataframe",
-                example: r#"let df = ([[a b]; [1 2] [3 0] [1 2]] | dfr to-df);
+                example: r#"let df = ([[a b]; [1 2] [3 0] [1 2]] | to-df);
     let res = ($df.b / $df.b);
-    let a = ($df | dfr with-column $res --name res);
-    $a | dfr drop-nulls"#,
+    let a = ($df | with-column $res --name res);
+    $a | drop-nulls"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -59,8 +59,8 @@ impl Command for DropNulls {
             },
             Example {
                 description: "drop null values in dataframe",
-                example: r#"let s = ([1 2 0 0 3 4] | dfr to-df);
-    ($s / $s) | dfr drop-nulls"#,
+                example: r#"let s = ([1 2 0 0 3 4] | to-df);
+    ($s / $s) | drop-nulls"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "div_0_0".to_string(),
@@ -78,6 +78,14 @@ impl Command for DropNulls {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/dtypes.rs

@@ -2,7 +2,7 @@ use super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 
 #[derive(Clone)]
@@ -10,7 +10,7 @@ pub struct DataTypes;
 
 impl Command for DataTypes {
     fn name(&self) -> &str {
-        "dfr dtypes"
+        "dtypes"
     }
 
     fn usage(&self) -> &str {
@@ -24,7 +24,7 @@ impl Command for DataTypes {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Dataframe dtypes",
-            example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr dtypes",
+            example: "[[a b]; [1 2] [3 4]] | to-df | dtypes",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new(
@@ -42,6 +42,14 @@ impl Command for DataTypes {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/dummies.rs

@@ -2,7 +2,7 @@ use super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::DataFrameOps;
 
@@ -11,7 +11,7 @@ pub struct Dummies;
 
 impl Command for Dummies {
     fn name(&self) -> &str {
-        "dfr to-dummies"
+        "to-dummies"
     }
 
     fn usage(&self) -> &str {
@@ -26,7 +26,7 @@ impl Command for Dummies {
         vec![
             Example {
                 description: "Create new dataframe with dummy variables from a dataframe",
-                example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr to-dummies",
+                example: "[[a b]; [1 2] [3 4]] | to-df | to-dummies",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -52,7 +52,7 @@ impl Command for Dummies {
             },
             Example {
                 description: "Create new dataframe with dummy variables from a series",
-                example: "[1 2 2 3 3] | dfr to-df | dfr to-dummies",
+                example: "[1 2 2 3 3] | to-df | to-dummies",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -93,6 +93,14 @@ impl Command for Dummies {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/filter_with.rs

@@ -2,7 +2,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::LazyFrame;
 
@@ -15,7 +15,7 @@ pub struct FilterWith;
 
 impl Command for FilterWith {
     fn name(&self) -> &str {
-        "dfr filter-with"
+        "filter-with"
     }
 
     fn usage(&self) -> &str {
@@ -36,8 +36,8 @@ impl Command for FilterWith {
         vec![
             Example {
                 description: "Filter dataframe using a bool mask",
-                example: r#"let mask = ([true false] | dfr to-df);
-    [[a b]; [1 2] [3 4]] | dfr to-df | dfr filter-with $mask"#,
+                example: r#"let mask = ([true false] | to-df);
+    [[a b]; [1 2] [3 4]] | to-df | filter-with $mask"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new("a".to_string(), vec![Value::test_int(1)]),
@@ -49,7 +49,7 @@ impl Command for FilterWith {
             },
             Example {
                 description: "Filter dataframe using an expression",
-                example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr filter-with ((dfr col a) > 1)",
+                example: "[[a b]; [1 2] [3 4]] | to-df | filter-with ((col a) > 1)",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new("a".to_string(), vec![Value::test_int(3)]),
@@ -62,6 +62,14 @@ impl Command for FilterWith {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,
@@ -74,16 +82,9 @@ impl Command for FilterWith {
         if NuLazyFrame::can_downcast(&value) {
             let df = NuLazyFrame::try_from_value(value)?;
             command_lazy(engine_state, stack, call, df)
-        } else if NuDataFrame::can_downcast(&value) {
+        } else {
             let df = NuDataFrame::try_from_value(value)?;
             command_eager(engine_state, stack, call, df)
-        } else {
-            Err(ShellError::CantConvert(
-                "expression or query".into(),
-                value.get_type().to_string(),
-                value.span()?,
-                None,
-            ))
         }
     }
 }

crates/nu-command/src/dataframe/eager/first.rs

@@ -1,10 +1,9 @@
 use super::super::values::{utils::DEFAULT_ROWS, Column, NuDataFrame};
-use crate::dataframe::values::NuExpression;
 use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -12,39 +11,40 @@ pub struct FirstDF;
 
 impl Command for FirstDF {
     fn name(&self) -> &str {
-        "dfr first"
+        "first"
     }
 
     fn usage(&self) -> &str {
-        "Creates new dataframe with first rows or creates a first expression"
+        "Creates new dataframe with first rows"
     }
 
     fn signature(&self) -> Signature {
         Signature::build(self.name())
             .optional("rows", SyntaxShape::Int, "Number of rows for head")
-            .category(Category::Custom("dataframe or expression".into()))
+            .category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![
-            Example {
-                description: "Create new dataframe with head rows",
-                example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr first 1",
-                result: Some(
-                    NuDataFrame::try_from_columns(vec![
-                        Column::new("a".to_string(), vec![Value::test_int(1)]),
-                        Column::new("b".to_string(), vec![Value::test_int(2)]),
-                    ])
-                    .expect("simple df for test should not fail")
-                    .into_value(Span::test_data()),
-                ),
-            },
-            Example {
-                description: "Creates a first expression from a column",
-                example: "dfr col a | dfr first",
-                result: None,
-            },
-        ]
+        vec![Example {
+            description: "Create new dataframe with head rows",
+            example: "[[a b]; [1 2] [3 4]] | to-df | first 1",
+            result: Some(
+                NuDataFrame::try_from_columns(vec![
+                    Column::new("a".to_string(), vec![Value::test_int(1)]),
+                    Column::new("b".to_string(), vec![Value::test_int(2)]),
+                ])
+                .expect("simple df for test should not fail")
+                .into_value(Span::test_data()),
+            ),
+        }]
+    }
+
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
     }
 
     fn run(
@@ -54,27 +54,8 @@ impl Command for FirstDF {
         call: &Call,
         input: PipelineData,
     ) -> Result<PipelineData, ShellError> {
-        let value = input.into_value(call.head);
-
-        if NuExpression::can_downcast(&value) {
-            let expr = NuExpression::try_from_value(value)?;
-            let expr: NuExpression = expr.into_polars().is_null().into();
-
-            Ok(PipelineData::Value(
-                NuExpression::into_value(expr, call.head),
-                None,
-            ))
-        } else if NuDataFrame::can_downcast(&value) {
-            let df = NuDataFrame::try_from_value(value)?;
-            command(engine_state, stack, call, df)
-        } else {
-            Err(ShellError::CantConvert(
-                "expression or query".into(),
-                value.get_type().to_string(),
-                value.span()?,
-                None,
-            ))
-        }
+        let df = NuDataFrame::try_from_pipeline(input, call.head)?;
+        command(engine_state, stack, call, df)
     }
 }
 

crates/nu-command/src/dataframe/eager/get.rs

@@ -2,7 +2,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 use crate::dataframe::values::utils::convert_columns_string;
@@ -14,7 +14,7 @@ pub struct GetDF;
 
 impl Command for GetDF {
     fn name(&self) -> &str {
-        "dfr get"
+        "get"
     }
 
     fn usage(&self) -> &str {
@@ -29,8 +29,8 @@ impl Command for GetDF {
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
-            description: "Creates dataframe with selected columns",
-            example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr get a",
+            description: "Returns the selected column",
+            example: "[[a b]; [1 2] [3 4]] | to-df | get a",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "a".to_string(),
@@ -42,6 +42,14 @@ impl Command for GetDF {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/last.rs

@@ -1,10 +1,9 @@
 use super::super::values::{utils::DEFAULT_ROWS, Column, NuDataFrame};
-use crate::dataframe::values::NuExpression;
 use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -12,7 +11,7 @@ pub struct LastDF;
 
 impl Command for LastDF {
     fn name(&self) -> &str {
-        "dfr last"
+        "last"
     }
 
     fn usage(&self) -> &str {
@@ -22,29 +21,30 @@ impl Command for LastDF {
     fn signature(&self) -> Signature {
         Signature::build(self.name())
             .optional("rows", SyntaxShape::Int, "Number of rows for tail")
-            .category(Category::Custom("dataframe or lazyframe".into()))
+            .category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![
-            Example {
-                description: "Create new dataframe with last rows",
-                example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr last 1",
-                result: Some(
-                    NuDataFrame::try_from_columns(vec![
-                        Column::new("a".to_string(), vec![Value::test_int(3)]),
-                        Column::new("b".to_string(), vec![Value::test_int(4)]),
-                    ])
-                    .expect("simple df for test should not fail")
-                    .into_value(Span::test_data()),
-                ),
-            },
-            Example {
-                description: "Creates a last expression from a column",
-                example: "dfr col a | dfr last",
-                result: None,
-            },
-        ]
+        vec![Example {
+            description: "Create new dataframe with last rows",
+            example: "[[a b]; [1 2] [3 4]] | to-df | last 1",
+            result: Some(
+                NuDataFrame::try_from_columns(vec![
+                    Column::new("a".to_string(), vec![Value::test_int(3)]),
+                    Column::new("b".to_string(), vec![Value::test_int(4)]),
+                ])
+                .expect("simple df for test should not fail")
+                .into_value(Span::test_data()),
+            ),
+        }]
+    }
+
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
     }
 
     fn run(
@@ -54,27 +54,8 @@ impl Command for LastDF {
         call: &Call,
         input: PipelineData,
     ) -> Result<PipelineData, ShellError> {
-        let value = input.into_value(call.head);
-
-        if NuExpression::can_downcast(&value) {
-            let expr = NuExpression::try_from_value(value)?;
-            let expr: NuExpression = expr.into_polars().is_null().into();
-
-            Ok(PipelineData::Value(
-                NuExpression::into_value(expr, call.head),
-                None,
-            ))
-        } else if NuDataFrame::can_downcast(&value) {
-            let df = NuDataFrame::try_from_value(value)?;
-            command(engine_state, stack, call, df)
-        } else {
-            Err(ShellError::CantConvert(
-                "expression or query".into(),
-                value.get_type().to_string(),
-                value.span()?,
-                None,
-            ))
-        }
+        let df = NuDataFrame::try_from_pipeline(input, call.head)?;
+        command(engine_state, stack, call, df)
     }
 }
 

crates/nu-command/src/dataframe/eager/list.rs

@@ -11,7 +11,7 @@ pub struct ListDF;
 
 impl Command for ListDF {
     fn name(&self) -> &str {
-        "dfr ls"
+        "ls-df"
     }
 
     fn usage(&self) -> &str {
@@ -25,8 +25,8 @@ impl Command for ListDF {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Creates a new dataframe and shows it in the dataframe list",
-            example: r#"let test = ([[a b];[1 2] [3 4]] | dfr to-df);
-    dfr ls"#,
+            example: r#"let test = ([[a b];[1 2] [3 4]] | to-df);
+    ls-df"#,
             result: None,
         }]
     }

crates/nu-command/src/dataframe/eager/melt.rs

@@ -2,7 +2,8 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Type,
+    Value,
 };
 
 use crate::dataframe::values::utils::convert_columns_string;
@@ -14,7 +15,7 @@ pub struct MeltDF;
 
 impl Command for MeltDF {
     fn name(&self) -> &str {
-        "dfr melt"
+        "melt"
     }
 
     fn usage(&self) -> &str {
@@ -53,8 +54,7 @@ impl Command for MeltDF {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "melt dataframe",
-            example:
-                "[[a b c d]; [x 1 4 a] [y 2 5 b] [z 3 6 c]] | dfr to-df | dfr melt -c [b c] -v [a d]",
+            example: "[[a b c d]; [x 1 4 a] [y 2 5 b] [z 3 6 c]] | to-df | melt -c [b c] -v [a d]",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new(
@@ -108,6 +108,14 @@ impl Command for MeltDF {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/mod.rs

@@ -1,6 +1,4 @@
 mod append;
-mod column;
-mod command;
 mod describe;
 mod drop;
 mod drop_duplicates;
@@ -28,8 +26,6 @@ mod with_column;
 use nu_protocol::engine::StateWorkingSet;
 
 pub use append::AppendDF;
-pub use column::ColumnDF;
-pub use command::Dataframe;
 pub use describe::DescribeDF;
 pub use drop::DropDF;
 pub use drop_duplicates::DropDuplicates;
@@ -67,8 +63,6 @@ pub fn add_eager_decls(working_set: &mut StateWorkingSet) {
     // Dataframe commands
     bind_command!(
         AppendDF,
-        ColumnDF,
-        Dataframe,
         DataTypes,
         DescribeDF,
         DropDF,

crates/nu-command/src/dataframe/eager/open.rs

@@ -3,7 +3,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape,
+    Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape, Type,
 };
 
 use std::{fs::File, io::BufReader, path::PathBuf};
@@ -15,7 +15,7 @@ pub struct OpenDataFrame;
 
 impl Command for OpenDataFrame {
     fn name(&self) -> &str {
-        "dfr open"
+        "open-df"
     }
 
     fn usage(&self) -> &str {
@@ -64,11 +64,19 @@ impl Command for OpenDataFrame {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Takes a file name and creates a dataframe",
-            example: "dfr open test.csv",
+            example: "open test.csv",
             result: None,
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Any
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/rename.rs

@@ -2,7 +2,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 use crate::dataframe::{utils::extract_strings, values::NuLazyFrame};
@@ -14,7 +14,7 @@ pub struct RenameDF;
 
 impl Command for RenameDF {
     fn name(&self) -> &str {
-        "dfr rename"
+        "rename"
     }
 
     fn usage(&self) -> &str {
@@ -40,7 +40,7 @@ impl Command for RenameDF {
         vec![
             Example {
                 description: "Renames a series",
-                example: "[5 6 7 8] | dfr to-df | dfr rename '0' new_name",
+                example: "[5 6 7 8] | to-df | rename '0' new_name",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "new_name".to_string(),
@@ -57,7 +57,7 @@ impl Command for RenameDF {
             },
             Example {
                 description: "Renames a dataframe column",
-                example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr rename a a_new",
+                example: "[[a b]; [1 2] [3 4]] | to-df | rename a a_new",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -75,7 +75,7 @@ impl Command for RenameDF {
             },
             Example {
                 description: "Renames two dataframe columns",
-                example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr rename [a b] [a_new b_new]",
+                example: "[[a b]; [1 2] [3 4]] | to-df | rename [a b] [a_new b_new]",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -94,6 +94,14 @@ impl Command for RenameDF {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,
@@ -106,16 +114,9 @@ impl Command for RenameDF {
         if NuLazyFrame::can_downcast(&value) {
             let df = NuLazyFrame::try_from_value(value)?;
             command_lazy(engine_state, stack, call, df)
-        } else if NuDataFrame::can_downcast(&value) {
+        } else {
             let df = NuDataFrame::try_from_value(value)?;
             command_eager(engine_state, stack, call, df)
-        } else {
-            Err(ShellError::CantConvert(
-                "expression or query".into(),
-                value.get_type().to_string(),
-                value.span()?,
-                None,
-            ))
         }
     }
 }

crates/nu-command/src/dataframe/eager/sample.rs

@@ -2,7 +2,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape,
+    Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape, Type,
 };
 
 use super::super::values::NuDataFrame;
@@ -12,7 +12,7 @@ pub struct SampleDF;
 
 impl Command for SampleDF {
     fn name(&self) -> &str {
-        "dfr sample"
+        "sample"
     }
 
     fn usage(&self) -> &str {
@@ -47,17 +47,25 @@ impl Command for SampleDF {
         vec![
             Example {
                 description: "Sample rows from dataframe",
-                example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr sample -n 1",
+                example: "[[a b]; [1 2] [3 4]] | to-df | sample -n 1",
                 result: None, // No expected value because sampling is random
             },
             Example {
                 description: "Shows sample row using fraction and replace",
-                example: "[[a b]; [1 2] [3 4] [5 6]] | dfr to-df | dfr sample -f 0.5 -e",
+                example: "[[a b]; [1 2] [3 4] [5 6]] | to-df | sample -f 0.5 -e",
                 result: None, // No expected value because sampling is random
             },
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/shape.rs

@@ -1,7 +1,7 @@
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 
 use crate::dataframe::values::Column;
@@ -13,7 +13,7 @@ pub struct ShapeDF;
 
 impl Command for ShapeDF {
     fn name(&self) -> &str {
-        "dfr shape"
+        "shape"
     }
 
     fn usage(&self) -> &str {
@@ -27,7 +27,7 @@ impl Command for ShapeDF {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Shows row and column shape",
-            example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr shape",
+            example: "[[a b]; [1 2] [3 4]] | to-df | shape",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new("rows".to_string(), vec![Value::test_int(2)]),
@@ -39,6 +39,14 @@ impl Command for ShapeDF {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/slice.rs

@@ -2,7 +2,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 use crate::dataframe::values::Column;
@@ -14,7 +14,7 @@ pub struct SliceDF;
 
 impl Command for SliceDF {
     fn name(&self) -> &str {
-        "dfr slice"
+        "slice"
     }
 
     fn usage(&self) -> &str {
@@ -31,7 +31,7 @@ impl Command for SliceDF {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Create new dataframe from a slice of the rows",
-            example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr slice 0 1",
+            example: "[[a b]; [1 2] [3 4]] | to-df | slice 0 1",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new("a".to_string(), vec![Value::test_int(1)]),
@@ -43,6 +43,14 @@ impl Command for SliceDF {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/take.rs

@@ -2,7 +2,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::DataType;
 
@@ -15,7 +15,7 @@ pub struct TakeDF;
 
 impl Command for TakeDF {
     fn name(&self) -> &str {
-        "dfr take"
+        "take"
     }
 
     fn usage(&self) -> &str {
@@ -36,9 +36,9 @@ impl Command for TakeDF {
         vec![
             Example {
                 description: "Takes selected rows from dataframe",
-                example: r#"let df = ([[a b]; [4 1] [5 2] [4 3]] | dfr to-df);
-    let indices = ([0 2] | dfr to-df);
-    $df | dfr take $indices"#,
+                example: r#"let df = ([[a b]; [4 1] [5 2] [4 3]] | to-df);
+    let indices = ([0 2] | to-df);
+    $df | take $indices"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -56,9 +56,9 @@ impl Command for TakeDF {
             },
             Example {
                 description: "Takes selected rows from series",
-                example: r#"let series = ([4 1 5 2 4 3] | dfr to-df);
-    let indices = ([0 2] | dfr to-df);
-    $series | dfr take $indices"#,
+                example: r#"let series = ([4 1 5 2 4 3] | to-df);
+    let indices = ([0 2] | to-df);
+    $series | take $indices"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "0".to_string(),
@@ -71,6 +71,14 @@ impl Command for TakeDF {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/to_csv.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape, Type, Value,
 };
 use polars::prelude::{CsvWriter, SerWriter};
 
@@ -15,7 +15,7 @@ pub struct ToCSV;
 
 impl Command for ToCSV {
     fn name(&self) -> &str {
-        "dfr to-csv"
+        "to-csv"
     }
 
     fn usage(&self) -> &str {
@@ -39,17 +39,25 @@ impl Command for ToCSV {
         vec![
             Example {
                 description: "Saves dataframe to csv file",
-                example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr to-csv test.csv",
+                example: "[[a b]; [1 2] [3 4]] | to-df | to-csv test.csv",
                 result: None,
             },
             Example {
                 description: "Saves dataframe to csv file using other delimiter",
-                example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr to-csv test.csv -d '|'",
+                example: "[[a b]; [1 2] [3 4]] | to-df | to-csv test.csv -d '|'",
                 result: None,
             },
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Any
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/to_df.rs

@@ -3,7 +3,7 @@ use super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 
 #[derive(Clone)]
@@ -11,7 +11,7 @@ pub struct ToDataFrame;
 
 impl Command for ToDataFrame {
     fn name(&self) -> &str {
-        "dfr to-df"
+        "to-df"
     }
 
     fn usage(&self) -> &str {
@@ -26,7 +26,7 @@ impl Command for ToDataFrame {
         vec![
             Example {
                 description: "Takes a dictionary and creates a dataframe",
-                example: "[[a b];[1 2] [3 4]] | dfr to-df",
+                example: "[[a b];[1 2] [3 4]] | to-df",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -44,7 +44,7 @@ impl Command for ToDataFrame {
             },
             Example {
                 description: "Takes a list of tables and creates a dataframe",
-                example: "[[1 2 a] [3 4 b] [5 6 c]] | dfr to-df",
+                example: "[[1 2 a] [3 4 b] [5 6 c]] | to-df",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -70,7 +70,7 @@ impl Command for ToDataFrame {
             },
             Example {
                 description: "Takes a list and creates a dataframe",
-                example: "[a b c] | dfr to-df",
+                example: "[a b c] | to-df",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "0".to_string(),
@@ -86,7 +86,7 @@ impl Command for ToDataFrame {
             },
             Example {
                 description: "Takes a list of booleans and creates a dataframe",
-                example: "[true true false] | dfr to-df",
+                example: "[true true false] | to-df",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "0".to_string(),
@@ -103,6 +103,14 @@ impl Command for ToDataFrame {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Any
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         _engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/to_nu.rs

@@ -2,7 +2,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
 };
 
 use super::super::values::NuDataFrame;
@@ -12,7 +12,7 @@ pub struct ToNu;
 
 impl Command for ToNu {
     fn name(&self) -> &str {
-        "dfr to-nu"
+        "to-nu"
     }
 
     fn usage(&self) -> &str {
@@ -22,7 +22,7 @@ impl Command for ToNu {
     fn signature(&self) -> Signature {
         Signature::build(self.name())
             .named(
-                "n-rows",
+                "rows",
                 SyntaxShape::Number,
                 "number of rows to be shown",
                 Some('n'),
@@ -35,17 +35,25 @@ impl Command for ToNu {
         vec![
             Example {
                 description: "Shows head rows from dataframe",
-                example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr to-nu",
+                example: "[[a b]; [1 2] [3 4]] | to-df | to nu",
                 result: None,
             },
             Example {
                 description: "Shows tail rows from dataframe",
-                example: "[[a b]; [1 2] [3 4] [5 6]] | dfr to-df | dfr to-nu -t -n 1",
+                example: "[[a b]; [1 2] [3 4] [5 6]] | to-df | to nu -t -n 1",
                 result: None,
             },
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Any
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/to_parquet.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Spanned, SyntaxShape, Type, Value,
 };
 use polars::prelude::ParquetWriter;
 
@@ -15,7 +15,7 @@ pub struct ToParquet;
 
 impl Command for ToParquet {
     fn name(&self) -> &str {
-        "dfr to-parquet"
+        "to-parquet"
     }
 
     fn usage(&self) -> &str {
@@ -30,12 +30,20 @@ impl Command for ToParquet {
 
     fn examples(&self) -> Vec<Example> {
         vec![Example {
-            description: "Saves dataframe to csv file",
-            example: "[[a b]; [1 2] [3 4]] | dfr to-df | dfr to-parquet test.parquet",
+            description: "Saves dataframe to parquet file",
+            example: "[[a b]; [1 2] [3 4]] | to-df | to-parquet test.parquet",
             result: None,
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Any
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/eager/with_column.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -12,7 +12,7 @@ pub struct WithColumn;
 
 impl Command for WithColumn {
     fn name(&self) -> &str {
-        "dfr with-column"
+        "with-column"
     }
 
     fn usage(&self) -> &str {
@@ -34,9 +34,9 @@ impl Command for WithColumn {
         vec![
             Example {
                 description: "Adds a series to the dataframe",
-                example: r#"[[a b]; [1 2] [3 4]] 
-    | dfr to-df 
-    | dfr with-column ([5 6] | dfr to-df) --name c"#,
+                example: r#"[[a b]; [1 2] [3 4]]
+    | to-df
+    | with-column ([5 6] | to-df) --name c"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -58,13 +58,13 @@ impl Command for WithColumn {
             },
             Example {
                 description: "Adds a series to the dataframe",
-                example: r#"[[a b]; [1 2] [3 4]] 
-    | dfr to-lazy
-    | dfr with-column [
-        ((dfr col a) * 2 | dfr as "c")
-        ((dfr col a) * 3 | dfr as "d")
+                example: r#"[[a b]; [1 2] [3 4]]
+    | to-lazy
+    | with-column [
+        ((col a) * 2 | as "c")
+        ((col a) * 3 | as "d")
       ]
-    | dfr collect"#,
+    | collect"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -91,6 +91,14 @@ impl Command for WithColumn {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/expressions/alias.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -12,7 +12,7 @@ pub struct ExprAlias;
 
 impl Command for ExprAlias {
     fn name(&self) -> &str {
-        "dfr as"
+        "as"
     }
 
     fn usage(&self) -> &str {
@@ -32,7 +32,7 @@ impl Command for ExprAlias {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Creates and alias expression",
-            example: "dfr col a | dfr as new_a | dfr as-nu",
+            example: "col a | as new_a | to-nu",
             result: {
                 let cols = vec!["expr".into(), "value".into()];
                 let expr = Value::test_string("column");
@@ -57,6 +57,14 @@ impl Command for ExprAlias {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("expression".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("expression".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/expressions/as_nu.rs

@@ -3,7 +3,7 @@ use super::super::values::NuExpression;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 
 #[derive(Clone)]
@@ -11,7 +11,7 @@ pub struct ExprAsNu;
 
 impl Command for ExprAsNu {
     fn name(&self) -> &str {
-        "dfr as-nu"
+        "to-nu"
     }
 
     fn usage(&self) -> &str {
@@ -25,7 +25,7 @@ impl Command for ExprAsNu {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Convert a col expression into a nushell value",
-            example: "dfr col col_a | dfr as-nu",
+            example: "col a | to-nu",
             result: Some(Value::Record {
                 cols: vec!["expr".into(), "value".into()],
                 vals: vec![
@@ -34,7 +34,7 @@ impl Command for ExprAsNu {
                         span: Span::test_data(),
                     },
                     Value::String {
-                        val: "col_a".into(),
+                        val: "a".into(),
                         span: Span::test_data(),
                     },
                 ],
@@ -43,6 +43,14 @@ impl Command for ExprAsNu {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("expression".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Any
+    }
+
     fn run(
         &self,
         _engine_state: &EngineState,

crates/nu-command/src/dataframe/expressions/col.rs

@@ -3,7 +3,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::col;
 
@@ -12,7 +12,7 @@ pub struct ExprCol;
 
 impl Command for ExprCol {
     fn name(&self) -> &str {
-        "dfr col"
+        "col"
     }
 
     fn usage(&self) -> &str {
@@ -32,7 +32,7 @@ impl Command for ExprCol {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Creates a named column expression and converts it to a nu object",
-            example: "dfr col col_a | dfr as-nu",
+            example: "col a | to-nu",
             result: Some(Value::Record {
                 cols: vec!["expr".into(), "value".into()],
                 vals: vec![
@@ -41,7 +41,7 @@ impl Command for ExprCol {
                         span: Span::test_data(),
                     },
                     Value::String {
-                        val: "col_a".into(),
+                        val: "a".into(),
                         span: Span::test_data(),
                     },
                 ],
@@ -50,6 +50,14 @@ impl Command for ExprCol {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Any
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("expression".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/expressions/expressions_macro.rs

@@ -1,18 +1,17 @@
 /// Definition of multiple Expression commands using a macro rule
 /// All of these expressions have an identical body and only require
 /// to have a change in the name, description and expression function
-use super::super::values::NuExpression;
-
+use crate::dataframe::values::{Column, NuDataFrame, NuExpression};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 
 // The structs defined in this file are structs that form part of other commands
 // since they share a similar name
 macro_rules! expr_command {
-    ($command: ident, $name: expr, $desc: expr, $examples: expr, $func: ident) => {
+    ($command: ident, $name: expr, $desc: expr, $examples: expr, $func: ident, $test: ident) => {
         #[derive(Clone)]
         pub struct $command;
 
@@ -33,6 +32,14 @@ macro_rules! expr_command {
                 $examples
             }
 
+            fn input_type(&self) -> Type {
+                Type::Custom("expression".into())
+            }
+
+            fn output_type(&self) -> Type {
+                Type::Custom("expression".into())
+            }
+
             fn run(
                 &self,
                 _engine_state: &EngineState,
@@ -49,6 +56,23 @@ macro_rules! expr_command {
                 ))
             }
         }
+
+        #[cfg(test)]
+        mod $test {
+            use super::super::super::test_dataframe::test_dataframe;
+            use super::*;
+            use crate::dataframe::lazy::aggregate::LazyAggregate;
+            use crate::dataframe::lazy::groupby::ToLazyGroupBy;
+
+            #[test]
+            fn test_examples() {
+                test_dataframe(vec![
+                    Box::new($command {}),
+                    Box::new(LazyAggregate {}),
+                    Box::new(ToLazyGroupBy {}),
+                ])
+            }
+        }
     };
 }
 
@@ -56,68 +80,380 @@ macro_rules! expr_command {
 // Expands to a command definition for a list expression
 expr_command!(
     ExprList,
-    "dfr list",
+    "list",
     "Aggregates a group to a Series",
     vec![Example {
         description: "",
         example: "",
         result: None,
     }],
-    list
+    list,
+    test_list
 );
 
 // ExprAggGroups command
 // Expands to a command definition for a agg groups expression
 expr_command!(
     ExprAggGroups,
-    "dfr agg-groups",
+    "agg-groups",
     "creates an agg_groups expression",
     vec![Example {
         description: "",
         example: "",
         result: None,
     }],
-    agg_groups
+    agg_groups,
+    test_groups
 );
 
 // ExprFlatten command
 // Expands to a command definition for a flatten expression
 expr_command!(
     ExprFlatten,
-    "dfr flatten",
+    "flatten",
     "creates a flatten expression",
     vec![Example {
         description: "",
         example: "",
         result: None,
     }],
-    flatten
+    flatten,
+    test_flatten
 );
 
 // ExprExplode command
 // Expands to a command definition for a explode expression
 expr_command!(
     ExprExplode,
-    "dfr explode",
+    "explode",
     "creates an explode expression",
     vec![Example {
         description: "",
         example: "",
         result: None,
     }],
-    explode
+    explode,
+    test_explode
 );
 
 // ExprCount command
 // Expands to a command definition for a count expression
 expr_command!(
     ExprCount,
-    "dfr count",
+    "count",
     "creates a count expression",
     vec![Example {
         description: "",
         example: "",
         result: None,
     }],
-    count
+    count,
+    test_count
+);
+
+// ExprFirst command
+// Expands to a command definition for a count expression
+expr_command!(
+    ExprFirst,
+    "first",
+    "creates a first expression",
+    vec![Example {
+        description: "Creates a first expression from a column",
+        example: "col a | first",
+        result: None,
+    },],
+    first,
+    test_first
+);
+
+// ExprLast command
+// Expands to a command definition for a count expression
+expr_command!(
+    ExprLast,
+    "last",
+    "creates a last expression",
+    vec![Example {
+        description: "Creates a last expression from a column",
+        example: "col a | last",
+        result: None,
+    },],
+    last,
+    test_last
+);
+
+// ExprNUnique command
+// Expands to a command definition for a n-unique expression
+expr_command!(
+    ExprNUnique,
+    "n-unique",
+    "creates a n-unique expression",
+    vec![Example {
+        description: "Creates a is n-unique expression from a column",
+        example: "col a | n-unique",
+        result: None,
+    },],
+    n_unique,
+    test_nunique
+);
+
+// ExprIsNotNull command
+// Expands to a command definition for a n-unique expression
+expr_command!(
+    ExprIsNotNull,
+    "is-not-null",
+    "creates a is not null expression",
+    vec![Example {
+        description: "Creates a is not null expression from a column",
+        example: "col a | is-not-null",
+        result: None,
+    },],
+    is_not_null,
+    test_is_not_null
+);
+
+// ExprIsNull command
+// Expands to a command definition for a n-unique expression
+expr_command!(
+    ExprIsNull,
+    "is-null",
+    "creates a is null expression",
+    vec![Example {
+        description: "Creates a is null expression from a column",
+        example: "col a | is-null",
+        result: None,
+    },],
+    is_null,
+    test_is_null
+);
+
+// ExprNot command
+// Expands to a command definition for a not expression
+expr_command!(
+    ExprNot,
+    "expr-not",
+    "creates a not expression",
+    vec![Example {
+        description: "Creates a not expression",
+        example: "(col a) > 2) | expr-not",
+        result: None,
+    },],
+    not,
+    test_not
+);
+
+// ExprMax command
+// Expands to a command definition for max aggregation
+expr_command!(
+    ExprMax,
+    "max",
+    "Creates a max expression",
+    vec![Example {
+        description: "Max aggregation for a group by",
+        example: r#"[[a b]; [one 2] [one 4] [two 1]]
+    | to-df
+    | group-by a
+    | agg (col b | max)"#,
+        result: Some(
+            NuDataFrame::try_from_columns(vec![
+                Column::new(
+                    "a".to_string(),
+                    vec![Value::test_string("one"), Value::test_string("two")],
+                ),
+                Column::new(
+                    "b".to_string(),
+                    vec![Value::test_int(4), Value::test_int(1)],
+                ),
+            ])
+            .expect("simple df for test should not fail")
+            .into_value(Span::test_data()),
+        ),
+    },],
+    max,
+    test_max
+);
+
+// ExprMin command
+// Expands to a command definition for min aggregation
+expr_command!(
+    ExprMin,
+    "min",
+    "Creates a min expression",
+    vec![Example {
+        description: "Min aggregation for a group by",
+        example: r#"[[a b]; [one 2] [one 4] [two 1]]
+    | to-df
+    | group-by a
+    | agg (col b | min)"#,
+        result: Some(
+            NuDataFrame::try_from_columns(vec![
+                Column::new(
+                    "a".to_string(),
+                    vec![Value::test_string("one"), Value::test_string("two")],
+                ),
+                Column::new(
+                    "b".to_string(),
+                    vec![Value::test_int(2), Value::test_int(1)],
+                ),
+            ])
+            .expect("simple df for test should not fail")
+            .into_value(Span::test_data()),
+        ),
+    },],
+    min,
+    test_min
+);
+
+// ExprSum command
+// Expands to a command definition for sum aggregation
+expr_command!(
+    ExprSum,
+    "sum",
+    "Creates a sum expression for an aggregation",
+    vec![Example {
+        description: "Sum aggregation for a group by",
+        example: r#"[[a b]; [one 2] [one 4] [two 1]]
+    | to-df
+    | group-by a
+    | agg (col b | sum)"#,
+        result: Some(
+            NuDataFrame::try_from_columns(vec![
+                Column::new(
+                    "a".to_string(),
+                    vec![Value::test_string("one"), Value::test_string("two")],
+                ),
+                Column::new(
+                    "b".to_string(),
+                    vec![Value::test_int(6), Value::test_int(1)],
+                ),
+            ])
+            .expect("simple df for test should not fail")
+            .into_value(Span::test_data()),
+        ),
+    },],
+    sum,
+    test_sum
+);
+
+// ExprMean command
+// Expands to a command definition for mean aggregation
+expr_command!(
+    ExprMean,
+    "mean",
+    "Creates a mean expression for an aggregation",
+    vec![Example {
+        description: "Mean aggregation for a group by",
+        example: r#"[[a b]; [one 2] [one 4] [two 1]]
+    | to-df
+    | group-by a
+    | agg (col b | mean)"#,
+        result: Some(
+            NuDataFrame::try_from_columns(vec![
+                Column::new(
+                    "a".to_string(),
+                    vec![Value::test_string("one"), Value::test_string("two")],
+                ),
+                Column::new(
+                    "b".to_string(),
+                    vec![Value::test_float(3.0), Value::test_float(1.0)],
+                ),
+            ])
+            .expect("simple df for test should not fail")
+            .into_value(Span::test_data()),
+        ),
+    },],
+    mean,
+    test_mean
+);
+
+// ExprMedian command
+// Expands to a command definition for median aggregation
+expr_command!(
+    ExprMedian,
+    "median",
+    "Creates a median expression for an aggregation",
+    vec![Example {
+        description: "Median aggregation for a group by",
+        example: r#"[[a b]; [one 2] [one 4] [two 1]]
+    | to-df
+    | group-by a
+    | agg (col b | median)"#,
+        result: Some(
+            NuDataFrame::try_from_columns(vec![
+                Column::new(
+                    "a".to_string(),
+                    vec![Value::test_string("one"), Value::test_string("two")],
+                ),
+                Column::new(
+                    "b".to_string(),
+                    vec![Value::test_float(3.0), Value::test_float(1.0)],
+                ),
+            ])
+            .expect("simple df for test should not fail")
+            .into_value(Span::test_data()),
+        ),
+    },],
+    median,
+    test_median
+);
+
+// ExprStd command
+// Expands to a command definition for std aggregation
+expr_command!(
+    ExprStd,
+    "std",
+    "Creates a std expression for an aggregation",
+    vec![Example {
+        description: "Std aggregation for a group by",
+        example: r#"[[a b]; [one 2] [one 2] [two 1] [two 1]]
+    | to-df
+    | group-by a
+    | agg (col b | std)"#,
+        result: Some(
+            NuDataFrame::try_from_columns(vec![
+                Column::new(
+                    "a".to_string(),
+                    vec![Value::test_string("one"), Value::test_string("two")],
+                ),
+                Column::new(
+                    "b".to_string(),
+                    vec![Value::test_float(0.0), Value::test_float(0.0)],
+                ),
+            ])
+            .expect("simple df for test should not fail")
+            .into_value(Span::test_data()),
+        ),
+    },],
+    std,
+    test_std
+);
+
+// ExprVar command
+// Expands to a command definition for var aggregation
+expr_command!(
+    ExprVar,
+    "var",
+    "Create a var expression for an aggregation",
+    vec![Example {
+        description: "Var aggregation for a group by",
+        example: r#"[[a b]; [one 2] [one 2] [two 1] [two 1]]
+    | to-df
+    | group-by a
+    | agg (col b | var)"#,
+        result: Some(
+            NuDataFrame::try_from_columns(vec![
+                Column::new(
+                    "a".to_string(),
+                    vec![Value::test_string("one"), Value::test_string("two")],
+                ),
+                Column::new(
+                    "b".to_string(),
+                    vec![Value::test_float(0.0), Value::test_float(0.0)],
+                ),
+            ])
+            .expect("simple df for test should not fail")
+            .into_value(Span::test_data()),
+        ),
+    },],
+    var,
+    test_var
 );

crates/nu-command/src/dataframe/expressions/lit.rs

@@ -3,7 +3,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -11,7 +11,7 @@ pub struct ExprLit;
 
 impl Command for ExprLit {
     fn name(&self) -> &str {
-        "dfr lit"
+        "lit"
     }
 
     fn usage(&self) -> &str {
@@ -31,7 +31,7 @@ impl Command for ExprLit {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Created a literal expression and converts it to a nu object",
-            example: "dfr lit 2 | dfr as-nu",
+            example: "lit 2 | to-nu",
             result: Some(Value::Record {
                 cols: vec!["expr".into(), "value".into()],
                 vals: vec![
@@ -49,6 +49,14 @@ impl Command for ExprLit {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Any
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("expression".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/expressions/mod.rs

@@ -4,6 +4,7 @@ mod col;
 mod expressions_macro;
 mod lit;
 mod otherwise;
+mod quantile;
 mod when;
 
 use nu_protocol::engine::StateWorkingSet;
@@ -14,6 +15,7 @@ pub(super) use crate::dataframe::expressions::col::ExprCol;
 pub(crate) use crate::dataframe::expressions::expressions_macro::*;
 pub(super) use crate::dataframe::expressions::lit::ExprLit;
 pub(super) use crate::dataframe::expressions::otherwise::ExprOtherwise;
+pub(super) use crate::dataframe::expressions::quantile::ExprQuantile;
 pub(super) use crate::dataframe::expressions::when::ExprWhen;
 
 pub fn add_expressions(working_set: &mut StateWorkingSet) {
@@ -35,9 +37,24 @@ pub fn add_expressions(working_set: &mut StateWorkingSet) {
         ExprAsNu,
         ExprWhen,
         ExprOtherwise,
+        ExprQuantile,
         ExprList,
         ExprAggGroups,
         ExprFlatten,
-        ExprExplode
+        ExprExplode,
+        ExprCount,
+        ExprFirst,
+        ExprLast,
+        ExprNUnique,
+        ExprIsNotNull,
+        ExprIsNull,
+        ExprNot,
+        ExprMax,
+        ExprMin,
+        ExprSum,
+        ExprMean,
+        ExprMedian,
+        ExprStd,
+        ExprVar
     );
 }

crates/nu-command/src/dataframe/expressions/otherwise.rs

@@ -3,7 +3,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -11,7 +11,7 @@ pub struct ExprOtherwise;
 
 impl Command for ExprOtherwise {
     fn name(&self) -> &str {
-        "dfr otherwise"
+        "otherwise"
     }
 
     fn usage(&self) -> &str {
@@ -32,26 +32,25 @@ impl Command for ExprOtherwise {
         vec![
             Example {
                 description: "Create a when conditions",
-                example: "dfr when ((dfr col a) > 2) 4 | dfr otherwise 5",
+                example: "when ((col a) > 2) 4 | otherwise 5",
                 result: None,
             },
             Example {
                 description: "Create a when conditions",
-                example:
-                    "dfr when ((dfr col a) > 2) 4 | dfr when ((dfr col a) < 0) 6 | dfr otherwise 0",
+                example: "when ((col a) > 2) 4 | when ((col a) < 0) 6 | otherwise 0",
                 result: None,
             },
             Example {
                 description: "Create a new column for the dataframe",
                 example: r#"[[a b]; [6 2] [1 4] [4 1]]
-   | dfr to-lazy
-   | dfr with-column (
-       dfr when ((dfr col a) > 2) 4 | dfr otherwise 5 | dfr as c
+   | to-lazy
+   | with-column (
+       when ((col a) > 2) 4 | otherwise 5 | as c
      )
-   | dfr with-column (
-       dfr when ((dfr col a) > 5) 10 | dfr when ((dfr col a) < 2) 6 | dfr otherwise 0 | dfr as d
+   | with-column (
+       when ((col a) > 5) 10 | when ((col a) < 2) 6 | otherwise 0 | as d
      )
-   | dfr collect"#,
+   | collect"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -78,6 +77,14 @@ impl Command for ExprOtherwise {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Any
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("expression".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/expressions/quantile.rs

@@ -0,0 +1,102 @@
+use crate::dataframe::values::{Column, NuDataFrame, NuExpression};
+use nu_engine::CallExt;
+use nu_protocol::{
+    ast::Call,
+    engine::{Command, EngineState, Stack},
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
+};
+use polars::prelude::QuantileInterpolOptions;
+
+#[derive(Clone)]
+pub struct ExprQuantile;
+
+impl Command for ExprQuantile {
+    fn name(&self) -> &str {
+        "quantile"
+    }
+
+    fn usage(&self) -> &str {
+        "Aggregates the columns to the selected quantile"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build(self.name())
+            .required(
+                "quantile",
+                SyntaxShape::Number,
+                "quantile value for quantile operation",
+            )
+            .category(Category::Custom("expression".into()))
+    }
+
+    fn examples(&self) -> Vec<Example> {
+        vec![Example {
+            description: "Quantile aggregation for a group by",
+            example: r#"[[a b]; [one 2] [one 4] [two 1]]
+    | to-df
+    | group-by a
+    | agg (col b | quantile 0.5)"#,
+            result: Some(
+                NuDataFrame::try_from_columns(vec![
+                    Column::new(
+                        "a".to_string(),
+                        vec![Value::test_string("one"), Value::test_string("two")],
+                    ),
+                    Column::new(
+                        "b".to_string(),
+                        vec![Value::test_float(4.0), Value::test_float(1.0)],
+                    ),
+                ])
+                .expect("simple df for test should not fail")
+                .into_value(Span::test_data()),
+            ),
+        }]
+    }
+
+    fn input_type(&self) -> Type {
+        Type::Custom("expression".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("expression".into())
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        input: PipelineData,
+    ) -> Result<PipelineData, ShellError> {
+        let value = input.into_value(call.head);
+        let quantile: f64 = call.req(engine_state, stack, 0)?;
+
+        let expr = NuExpression::try_from_value(value)?;
+        let expr: NuExpression = expr
+            .into_polars()
+            .quantile(quantile, QuantileInterpolOptions::default())
+            .into();
+
+        Ok(PipelineData::Value(
+            NuExpression::into_value(expr, call.head),
+            None,
+        ))
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::super::super::test_dataframe::test_dataframe;
+    use super::*;
+    use crate::dataframe::lazy::aggregate::LazyAggregate;
+    use crate::dataframe::lazy::groupby::ToLazyGroupBy;
+
+    #[test]
+    fn test_examples() {
+        test_dataframe(vec![
+            Box::new(ExprQuantile {}),
+            Box::new(LazyAggregate {}),
+            Box::new(ToLazyGroupBy {}),
+        ])
+    }
+}

crates/nu-command/src/dataframe/expressions/when.rs

@@ -3,7 +3,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::when;
 
@@ -12,7 +12,7 @@ pub struct ExprWhen;
 
 impl Command for ExprWhen {
     fn name(&self) -> &str {
-        "dfr when"
+        "when"
     }
 
     fn usage(&self) -> &str {
@@ -38,25 +38,25 @@ impl Command for ExprWhen {
         vec![
             Example {
                 description: "Create a when conditions",
-                example: "dfr when ((dfr col a) > 2) 4",
+                example: "when ((col a) > 2) 4",
                 result: None,
             },
             Example {
                 description: "Create a when conditions",
-                example: "dfr when ((dfr col a) > 2) 4 | dfr when ((dfr col a) < 0) 6",
+                example: "when ((col a) > 2) 4 | when ((col a) < 0) 6",
                 result: None,
             },
             Example {
                 description: "Create a new column for the dataframe",
                 example: r#"[[a b]; [6 2] [1 4] [4 1]]
-   | dfr to-lazy
-   | dfr with-column (
-       dfr when ((dfr col a) > 2) 4 | dfr otherwise 5 | dfr as c
+   | to-lazy
+   | with-column (
+       when ((col a) > 2) 4 | otherwise 5 | as c
      )
-   | dfr with-column (
-       dfr when ((dfr col a) > 5) 10 | dfr when ((dfr col a) < 2) 6 | dfr otherwise 0 | dfr as d
+   | with-column (
+       when ((col a) > 5) 10 | when ((col a) < 2) 6 | otherwise 0 | as d
      )
-   | dfr collect"#,
+   | collect"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -83,6 +83,14 @@ impl Command for ExprWhen {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("expression".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("expression".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/lazy/aggregate.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -12,7 +12,7 @@ pub struct LazyAggregate;
 
 impl Command for LazyAggregate {
     fn name(&self) -> &str {
-        "dfr agg"
+        "agg"
     }
 
     fn usage(&self) -> &str {
@@ -34,12 +34,12 @@ impl Command for LazyAggregate {
             Example {
                 description: "Group by and perform an aggregation",
                 example: r#"[[a b]; [1 2] [1 4] [2 6] [2 4]]
-    | dfr to-df
-    | dfr group-by a
-    | dfr agg [
-        ("b" | dfr min | dfr as "b_min")
-        ("b" | dfr max | dfr as "b_max")
-        ("b" | dfr sum | dfr as "b_sum")
+    | to-df
+    | group-by a
+    | agg [
+        (col b | min | as "b_min")
+        (col b | max | as "b_max")
+        (col b | sum | as "b_sum")
      ]"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
@@ -67,14 +67,14 @@ impl Command for LazyAggregate {
             Example {
                 description: "Group by and perform an aggregation",
                 example: r#"[[a b]; [1 2] [1 4] [2 6] [2 4]]
-    | dfr to-lazy
-    | dfr group-by a
-    | dfr agg [
-        ("b" | dfr min | dfr as "b_min")
-        ("b" | dfr max | dfr as "b_max")
-        ("b" | dfr sum | dfr as "b_sum")
+    | to-lazy
+    | group-by a
+    | agg [
+        (col b | min | as "b_min")
+        (col b | max | as "b_max")
+        (col b | sum | as "b_sum")
      ]
-    | dfr collect"#,
+    | collect"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -101,6 +101,14 @@ impl Command for LazyAggregate {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,
@@ -133,9 +141,8 @@ impl Command for LazyAggregate {
 mod test {
     use super::super::super::test_dataframe::test_dataframe;
     use super::*;
-    use crate::dataframe::expressions::ExprAlias;
+    use crate::dataframe::expressions::{ExprAlias, ExprMax, ExprMin, ExprSum};
     use crate::dataframe::lazy::groupby::ToLazyGroupBy;
-    use crate::dataframe::lazy::{LazyMax, LazyMin, LazySum};
 
     #[test]
     fn test_examples() {
@@ -143,9 +150,9 @@ mod test {
             Box::new(LazyAggregate {}),
             Box::new(ToLazyGroupBy {}),
             Box::new(ExprAlias {}),
-            Box::new(LazyMin {}),
-            Box::new(LazyMax {}),
-            Box::new(LazySum {}),
+            Box::new(ExprMin {}),
+            Box::new(ExprMax {}),
+            Box::new(ExprSum {}),
         ])
     }
 }

crates/nu-command/src/dataframe/lazy/collect.rs

@@ -4,7 +4,7 @@ use super::super::values::NuLazyFrame;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 
 #[derive(Clone)]
@@ -12,7 +12,7 @@ pub struct LazyCollect;
 
 impl Command for LazyCollect {
     fn name(&self) -> &str {
-        "dfr collect"
+        "collect"
     }
 
     fn usage(&self) -> &str {
@@ -26,7 +26,7 @@ impl Command for LazyCollect {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "drop duplicates",
-            example: "[[a b]; [1 2] [3 4]] | dfr to-lazy | dfr collect",
+            example: "[[a b]; [1 2] [3 4]] | to-lazy | collect",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new(
@@ -44,6 +44,14 @@ impl Command for LazyCollect {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         _engine_state: &EngineState,

crates/nu-command/src/dataframe/lazy/fetch.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -12,7 +12,7 @@ pub struct LazyFetch;
 
 impl Command for LazyFetch {
     fn name(&self) -> &str {
-        "dfr fetch"
+        "fetch"
     }
 
     fn usage(&self) -> &str {
@@ -32,7 +32,7 @@ impl Command for LazyFetch {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Fetch a rows from the dataframe",
-            example: "[[a b]; [6 2] [4 2] [2 2]] | dfr to-df | dfr fetch 2",
+            example: "[[a b]; [6 2] [4 2] [2 2]] | to-df | fetch 2",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new(
@@ -50,6 +50,14 @@ impl Command for LazyFetch {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/lazy/fill_na.rs

@@ -3,7 +3,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -11,7 +11,7 @@ pub struct LazyFillNA;
 
 impl Command for LazyFillNA {
     fn name(&self) -> &str {
-        "dfr fill-na"
+        "fill-na"
     }
 
     fn usage(&self) -> &str {
@@ -36,6 +36,14 @@ impl Command for LazyFillNA {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/lazy/fill_null.rs

@@ -3,7 +3,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -11,7 +11,7 @@ pub struct LazyFillNull;
 
 impl Command for LazyFillNull {
     fn name(&self) -> &str {
-        "dfr fill-null"
+        "fill-null"
     }
 
     fn usage(&self) -> &str {
@@ -31,7 +31,7 @@ impl Command for LazyFillNull {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Fills the null values by 0",
-            example: "[1 2 2 3 3] | dfr to-df | dfr shift 2 | dfr fill-null 0",
+            example: "[1 2 2 3 3] | to-df | shift 2 | fill-null 0",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -49,6 +49,14 @@ impl Command for LazyFillNull {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/lazy/groupby.rs

@@ -3,7 +3,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::Expr;
 
@@ -12,7 +12,7 @@ pub struct ToLazyGroupBy;
 
 impl Command for ToLazyGroupBy {
     fn name(&self) -> &str {
-        "dfr group-by"
+        "group-by"
     }
 
     fn usage(&self) -> &str {
@@ -34,12 +34,12 @@ impl Command for ToLazyGroupBy {
             Example {
                 description: "Group by and perform an aggregation",
                 example: r#"[[a b]; [1 2] [1 4] [2 6] [2 4]]
-    | dfr to-df
-    | dfr group-by a
-    | dfr agg [
-        ("b" | dfr min | dfr as "b_min")
-        ("b" | dfr max | dfr as "b_max")
-        ("b" | dfr sum | dfr as "b_sum")
+    | to-df
+    | group-by a
+    | agg [
+        (col b | min | as "b_min")
+        (col b | max | as "b_max")
+        (col b | sum | as "b_sum")
      ]"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
@@ -67,14 +67,14 @@ impl Command for ToLazyGroupBy {
             Example {
                 description: "Group by and perform an aggregation",
                 example: r#"[[a b]; [1 2] [1 4] [2 6] [2 4]]
-    | dfr to-df
-    | dfr group-by a
-    | dfr agg [
-        ("b" | dfr min | dfr as "b_min")
-        ("b" | dfr max | dfr as "b_max")
-        ("b" | dfr sum | dfr as "b_sum")
+    | to-lazy
+    | group-by a
+    | agg [
+        (col b | min | as "b_min")
+        (col b | max | as "b_max")
+        (col b | sum | as "b_sum")
      ]
-    | dfr collect"#,
+    | collect"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -101,6 +101,14 @@ impl Command for ToLazyGroupBy {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,
@@ -143,9 +151,8 @@ impl Command for ToLazyGroupBy {
 mod test {
     use super::super::super::test_dataframe::test_dataframe;
     use super::*;
-    use crate::dataframe::expressions::ExprAlias;
+    use crate::dataframe::expressions::{ExprAlias, ExprMax, ExprMin, ExprSum};
     use crate::dataframe::lazy::aggregate::LazyAggregate;
-    use crate::dataframe::lazy::{LazyMax, LazyMin, LazySum};
 
     #[test]
     fn test_examples() {
@@ -153,9 +160,9 @@ mod test {
             Box::new(LazyAggregate {}),
             Box::new(ToLazyGroupBy {}),
             Box::new(ExprAlias {}),
-            Box::new(LazyMin {}),
-            Box::new(LazyMax {}),
-            Box::new(LazySum {}),
+            Box::new(ExprMin {}),
+            Box::new(ExprMax {}),
+            Box::new(ExprSum {}),
         ])
     }
 }

crates/nu-command/src/dataframe/lazy/join.rs

@@ -3,7 +3,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::{Expr, JoinType};
 
@@ -12,7 +12,7 @@ pub struct LazyJoin;
 
 impl Command for LazyJoin {
     fn name(&self) -> &str {
-        "dfr join"
+        "join"
     }
 
     fn usage(&self) -> &str {
@@ -45,9 +45,9 @@ impl Command for LazyJoin {
         vec![
             Example {
                 description: "Join two lazy dataframes",
-                example: r#"let df_a = ([[a b c];[1 "a" 0] [2 "b" 1] [1 "c" 2] [1 "c" 3]] | dfr to-lazy);
-    let df_b = ([["foo" "bar" "ham"];[1 "a" "let"] [2 "c" "var"] [3 "c" "const"]] | dfr to-lazy);
-    $df_a | dfr join $df_b a foo | dfr collect"#,
+                example: r#"let df_a = ([[a b c];[1 "a" 0] [2 "b" 1] [1 "c" 2] [1 "c" 3]] | to-lazy);
+    let df_b = ([["foo" "bar" "ham"];[1 "a" "let"] [2 "c" "var"] [3 "c" "const"]] | to-lazy);
+    $df_a | join $df_b a foo | collect"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -102,9 +102,9 @@ impl Command for LazyJoin {
             },
             Example {
                 description: "Join one eager dataframe with a lazy dataframe",
-                example: r#"let df_a = ([[a b c];[1 "a" 0] [2 "b" 1] [1 "c" 2] [1 "c" 3]] | dfr to-df);
-    let df_b = ([["foo" "bar" "ham"];[1 "a" "let"] [2 "c" "var"] [3 "c" "const"]] | dfr to-lazy);
-    $df_a | dfr join $df_b a foo"#,
+                example: r#"let df_a = ([[a b c];[1 "a" 0] [2 "b" 1] [1 "c" 2] [1 "c" 3]] | to-df);
+    let df_b = ([["foo" "bar" "ham"];[1 "a" "let"] [2 "c" "var"] [3 "c" "const"]] | to-lazy);
+    $df_a | join $df_b a foo"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -160,6 +160,14 @@ impl Command for LazyJoin {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/lazy/macro_commands.rs

@@ -1,11 +1,11 @@
 /// Definition of multiple lazyframe commands using a macro rule
 /// All of these commands have an identical body and only require
 /// to have a change in the name, description and function
-use crate::dataframe::values::{Column, NuDataFrame, NuExpression, NuLazyFrame};
+use crate::dataframe::values::{Column, NuDataFrame, NuLazyFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 
 macro_rules! lazy_command {
@@ -30,6 +30,14 @@ macro_rules! lazy_command {
                 $examples
             }
 
+            fn input_type(&self) -> Type {
+                Type::Custom("dataframe".into())
+            }
+
+            fn output_type(&self) -> Type {
+                Type::Custom("dataframe".into())
+            }
+
             fn run(
                 &self,
                 _engine_state: &EngineState,
@@ -61,11 +69,11 @@ macro_rules! lazy_command {
 // Expands to a command definition for reverse
 lazy_command!(
     LazyReverse,
-    "dfr reverse",
+    "reverse",
     "Reverses the LazyFrame",
     vec![Example {
         description: "Reverses the dataframe",
-        example: "[[a b]; [6 2] [4 2] [2 2]] | dfr to-df | dfr reverse",
+        example: "[[a b]; [6 2] [4 2] [2 2]] | to-df | reverse",
         result: Some(
             NuDataFrame::try_from_columns(vec![
                 Column::new(
@@ -89,398 +97,167 @@ lazy_command!(
 // Expands to a command definition for cache
 lazy_command!(
     LazyCache,
-    "dfr cache",
+    "cache",
     "Caches operations in a new LazyFrame",
     vec![Example {
         description: "Caches the result into a new LazyFrame",
-        example: "[[a b]; [6 2] [4 2] [2 2]] | dfr to-df | dfr reverse | dfr cache",
+        example: "[[a b]; [6 2] [4 2] [2 2]] | to-df | reverse | cache",
         result: None,
     }],
     cache,
     test_cache
 );
 
-// Creates a command that may result in a lazy frame operation or
-// lazy frame expression
-macro_rules! lazy_expr_command {
-    ($command: ident, $name: expr, $desc: expr, $examples: expr, $func: ident, $test: ident) => {
-        #[derive(Clone)]
-        pub struct $command;
-
-        impl Command for $command {
-            fn name(&self) -> &str {
-                $name
-            }
-
-            fn usage(&self) -> &str {
-                $desc
-            }
-
-            fn signature(&self) -> Signature {
-                Signature::build(self.name())
-                    .category(Category::Custom("lazyframe or expression".into()))
-            }
-
-            fn examples(&self) -> Vec<Example> {
-                $examples
-            }
-
-            fn run(
-                &self,
-                _engine_state: &EngineState,
-                _stack: &mut Stack,
-                call: &Call,
-                input: PipelineData,
-            ) -> Result<PipelineData, ShellError> {
-                let value = input.into_value(call.head);
-
-                if NuExpression::can_downcast(&value) {
-                    let expr = NuExpression::try_from_value(value)?;
-                    let expr: NuExpression = expr.into_polars().$func().into();
-
-                    Ok(PipelineData::Value(
-                        NuExpression::into_value(expr, call.head),
-                        None,
-                    ))
-                } else {
-                    let lazy = NuLazyFrame::try_from_value(value)?;
-                    let lazy = NuLazyFrame::new(lazy.from_eager, lazy.into_polars().$func());
-
-                    Ok(PipelineData::Value(lazy.into_value(call.head)?, None))
-                }
-            }
-        }
-
-        #[cfg(test)]
-        mod $test {
-            use super::super::super::test_dataframe::test_dataframe;
-            use super::*;
-            use crate::dataframe::lazy::aggregate::LazyAggregate;
-            use crate::dataframe::lazy::groupby::ToLazyGroupBy;
-
-            #[test]
-            fn test_examples() {
-                test_dataframe(vec![
-                    Box::new($command {}),
-                    Box::new(LazyAggregate {}),
-                    Box::new(ToLazyGroupBy {}),
-                ])
-            }
-        }
-    };
-}
-
 // LazyMax command
 // Expands to a command definition for max aggregation
-lazy_expr_command!(
+lazy_command!(
     LazyMax,
-    "dfr max",
-    "Aggregates columns to their max value or creates a max expression",
-    vec![
-        Example {
-            description: "Max value from columns in a dataframe",
-            example: "[[a b]; [6 2] [1 4] [4 1]] | dfr to-df | dfr max",
-            result: Some(
-                NuDataFrame::try_from_columns(vec![
-                    Column::new("a".to_string(), vec![Value::test_int(6)],),
-                    Column::new("b".to_string(), vec![Value::test_int(4)],),
-                ])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        },
-        Example {
-            description: "Max aggregation for a group by",
-            example: r#"[[a b]; [one 2] [one 4] [two 1]]
-    | dfr to-df
-    | dfr group-by a
-    | dfr agg ("b" | dfr max)"#,
-            result: Some(
-                NuDataFrame::try_from_columns(vec![
-                    Column::new(
-                        "a".to_string(),
-                        vec![Value::test_string("one"), Value::test_string("two")],
-                    ),
-                    Column::new(
-                        "b".to_string(),
-                        vec![Value::test_int(4), Value::test_int(1)],
-                    ),
-                ])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        },
-    ],
+    "max",
+    "Aggregates columns to their max value",
+    vec![Example {
+        description: "Max value from columns in a dataframe",
+        example: "[[a b]; [6 2] [1 4] [4 1]] | to-df | max",
+        result: Some(
+            NuDataFrame::try_from_columns(vec![
+                Column::new("a".to_string(), vec![Value::test_int(6)],),
+                Column::new("b".to_string(), vec![Value::test_int(4)],),
+            ])
+            .expect("simple df for test should not fail")
+            .into_value(Span::test_data()),
+        ),
+    },],
     max,
     test_max
 );
 
 // LazyMin command
 // Expands to a command definition for min aggregation
-lazy_expr_command!(
+lazy_command!(
     LazyMin,
-    "dfr min",
-    "Aggregates columns to their min value or creates a min expression",
-    vec![
-        Example {
-            description: "Min value from columns in a dataframe",
-            example: "[[a b]; [6 2] [1 4] [4 1]] | dfr to-df | dfr min",
-            result: Some(
-                NuDataFrame::try_from_columns(vec![
-                    Column::new("a".to_string(), vec![Value::test_int(1)],),
-                    Column::new("b".to_string(), vec![Value::test_int(1)],),
-                ])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        },
-        Example {
-            description: "Min aggregation for a group by",
-            example: r#"[[a b]; [one 2] [one 4] [two 1]]
-    | dfr to-df
-    | dfr group-by a
-    | dfr agg ("b" | dfr min)"#,
-            result: Some(
-                NuDataFrame::try_from_columns(vec![
-                    Column::new(
-                        "a".to_string(),
-                        vec![Value::test_string("one"), Value::test_string("two")],
-                    ),
-                    Column::new(
-                        "b".to_string(),
-                        vec![Value::test_int(2), Value::test_int(1)],
-                    ),
-                ])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        },
-    ],
+    "min",
+    "Aggregates columns to their min value",
+    vec![Example {
+        description: "Min value from columns in a dataframe",
+        example: "[[a b]; [6 2] [1 4] [4 1]] | to-df | min",
+        result: Some(
+            NuDataFrame::try_from_columns(vec![
+                Column::new("a".to_string(), vec![Value::test_int(1)],),
+                Column::new("b".to_string(), vec![Value::test_int(1)],),
+            ])
+            .expect("simple df for test should not fail")
+            .into_value(Span::test_data()),
+        ),
+    },],
     min,
     test_min
 );
 
 // LazySum command
 // Expands to a command definition for sum aggregation
-lazy_expr_command!(
+lazy_command!(
     LazySum,
-    "dfr sum",
-    "Aggregates columns to their sum value or creates a sum expression for an aggregation",
-    vec![
-        Example {
-            description: "Sums all columns in a dataframe",
-            example: "[[a b]; [6 2] [1 4] [4 1]] | dfr to-df | dfr sum",
-            result: Some(
-                NuDataFrame::try_from_columns(vec![
-                    Column::new("a".to_string(), vec![Value::test_int(11)],),
-                    Column::new("b".to_string(), vec![Value::test_int(7)],),
-                ])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        },
-        Example {
-            description: "Sum aggregation for a group by",
-            example: r#"[[a b]; [one 2] [one 4] [two 1]]
-    | dfr to-df
-    | dfr group-by a
-    | dfr agg ("b" | dfr sum)"#,
-            result: Some(
-                NuDataFrame::try_from_columns(vec![
-                    Column::new(
-                        "a".to_string(),
-                        vec![Value::test_string("one"), Value::test_string("two")],
-                    ),
-                    Column::new(
-                        "b".to_string(),
-                        vec![Value::test_int(6), Value::test_int(1)],
-                    ),
-                ])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        },
-    ],
+    "sum",
+    "Aggregates columns to their sum value",
+    vec![Example {
+        description: "Sums all columns in a dataframe",
+        example: "[[a b]; [6 2] [1 4] [4 1]] | to-df | sum",
+        result: Some(
+            NuDataFrame::try_from_columns(vec![
+                Column::new("a".to_string(), vec![Value::test_int(11)],),
+                Column::new("b".to_string(), vec![Value::test_int(7)],),
+            ])
+            .expect("simple df for test should not fail")
+            .into_value(Span::test_data()),
+        ),
+    },],
     sum,
     test_sum
 );
 
 // LazyMean command
 // Expands to a command definition for mean aggregation
-lazy_expr_command!(
+lazy_command!(
     LazyMean,
-    "dfr mean",
-    "Aggregates columns to their mean value or creates a mean expression for an aggregation",
-    vec![
-        Example {
-            description: "Mean value from columns in a dataframe",
-            example: "[[a b]; [6 2] [4 2] [2 2]] | dfr to-df | dfr mean",
-            result: Some(
-                NuDataFrame::try_from_columns(vec![
-                    Column::new("a".to_string(), vec![Value::test_float(4.0)],),
-                    Column::new("b".to_string(), vec![Value::test_float(2.0)],),
-                ])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        },
-        Example {
-            description: "Mean aggregation for a group by",
-            example: r#"[[a b]; [one 2] [one 4] [two 1]]
-    | dfr to-df
-    | dfr group-by a
-    | dfr agg ("b" | dfr mean)"#,
-            result: Some(
-                NuDataFrame::try_from_columns(vec![
-                    Column::new(
-                        "a".to_string(),
-                        vec![Value::test_string("one"), Value::test_string("two")],
-                    ),
-                    Column::new(
-                        "b".to_string(),
-                        vec![Value::test_float(3.0), Value::test_float(1.0)],
-                    ),
-                ])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        },
-    ],
+    "mean",
+    "Aggregates columns to their mean value",
+    vec![Example {
+        description: "Mean value from columns in a dataframe",
+        example: "[[a b]; [6 2] [4 2] [2 2]] | to-df | mean",
+        result: Some(
+            NuDataFrame::try_from_columns(vec![
+                Column::new("a".to_string(), vec![Value::test_float(4.0)],),
+                Column::new("b".to_string(), vec![Value::test_float(2.0)],),
+            ])
+            .expect("simple df for test should not fail")
+            .into_value(Span::test_data()),
+        ),
+    },],
     mean,
     test_mean
 );
 
 // LazyMedian command
 // Expands to a command definition for median aggregation
-lazy_expr_command!(
+lazy_command!(
     LazyMedian,
-    "dfr median",
-    "Aggregates columns to their median value or creates a median expression for an aggregation",
-    vec![
-        Example {
-            description: "Median value from columns in a dataframe",
-            example: "[[a b]; [6 2] [4 2] [2 2]] | dfr to-df | dfr median",
-            result: Some(
-                NuDataFrame::try_from_columns(vec![
-                    Column::new("a".to_string(), vec![Value::test_float(4.0)],),
-                    Column::new("b".to_string(), vec![Value::test_float(2.0)],),
-                ])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        },
-        Example {
-            description: "Median aggregation for a group by",
-            example: r#"[[a b]; [one 2] [one 4] [two 1]]
-    | dfr to-df
-    | dfr group-by a
-    | dfr agg ("b" | dfr median)"#,
-            result: Some(
-                NuDataFrame::try_from_columns(vec![
-                    Column::new(
-                        "a".to_string(),
-                        vec![Value::test_string("one"), Value::test_string("two")],
-                    ),
-                    Column::new(
-                        "b".to_string(),
-                        vec![Value::test_float(3.0), Value::test_float(1.0)],
-                    ),
-                ])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        },
-    ],
+    "median",
+    "Aggregates columns to their median value",
+    vec![Example {
+        description: "Median value from columns in a dataframe",
+        example: "[[a b]; [6 2] [4 2] [2 2]] | to-df | median",
+        result: Some(
+            NuDataFrame::try_from_columns(vec![
+                Column::new("a".to_string(), vec![Value::test_float(4.0)],),
+                Column::new("b".to_string(), vec![Value::test_float(2.0)],),
+            ])
+            .expect("simple df for test should not fail")
+            .into_value(Span::test_data()),
+        ),
+    },],
     median,
     test_median
 );
 
 // LazyStd command
 // Expands to a command definition for std aggregation
-lazy_expr_command!(
+lazy_command!(
     LazyStd,
-    "dfr std",
-    "Aggregates columns to their std value or creates a std expression for an aggregation",
-    vec![
-        Example {
-            description: "Std value from columns in a dataframe",
-            example: "[[a b]; [6 2] [4 2] [2 2]] | dfr to-df | dfr std",
-            result: Some(
-                NuDataFrame::try_from_columns(vec![
-                    Column::new("a".to_string(), vec![Value::test_float(2.0)],),
-                    Column::new("b".to_string(), vec![Value::test_float(0.0)],),
-                ])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        },
-        Example {
-            description: "Std aggregation for a group by",
-            example: r#"[[a b]; [one 2] [one 2] [two 1] [two 1]]
-    | dfr to-df
-    | dfr group-by a
-    | dfr agg ("b" | dfr std)"#,
-            result: Some(
-                NuDataFrame::try_from_columns(vec![
-                    Column::new(
-                        "a".to_string(),
-                        vec![Value::test_string("one"), Value::test_string("two")],
-                    ),
-                    Column::new(
-                        "b".to_string(),
-                        vec![Value::test_float(0.0), Value::test_float(0.0)],
-                    ),
-                ])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        },
-    ],
+    "std",
+    "Aggregates columns to their std value",
+    vec![Example {
+        description: "Std value from columns in a dataframe",
+        example: "[[a b]; [6 2] [4 2] [2 2]] | to-df | std",
+        result: Some(
+            NuDataFrame::try_from_columns(vec![
+                Column::new("a".to_string(), vec![Value::test_float(2.0)],),
+                Column::new("b".to_string(), vec![Value::test_float(0.0)],),
+            ])
+            .expect("simple df for test should not fail")
+            .into_value(Span::test_data()),
+        ),
+    },],
     std,
     test_std
 );
 
 // LazyVar command
 // Expands to a command definition for var aggregation
-lazy_expr_command!(
+lazy_command!(
     LazyVar,
-    "dfr var",
-    "Aggregates columns to their var value or create a var expression for an aggregation",
-    vec![
-        Example {
-            description: "Var value from columns in a dataframe",
-            example: "[[a b]; [6 2] [4 2] [2 2]] | dfr to-df | dfr var",
-            result: Some(
-                NuDataFrame::try_from_columns(vec![
-                    Column::new("a".to_string(), vec![Value::test_float(4.0)],),
-                    Column::new("b".to_string(), vec![Value::test_float(0.0)],),
-                ])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        },
-        Example {
-            description: "Var aggregation for a group by",
-            example: r#"[[a b]; [one 2] [one 2] [two 1] [two 1]]
-    | dfr to-df
-    | dfr group-by a
-    | dfr agg ("b" | dfr var)"#,
-            result: Some(
-                NuDataFrame::try_from_columns(vec![
-                    Column::new(
-                        "a".to_string(),
-                        vec![Value::test_string("one"), Value::test_string("two")],
-                    ),
-                    Column::new(
-                        "b".to_string(),
-                        vec![Value::test_float(0.0), Value::test_float(0.0)],
-                    ),
-                ])
-                .expect("simple df for test should not fail")
-                .into_value(Span::test_data()),
-            ),
-        },
-    ],
+    "var",
+    "Aggregates columns to their var value",
+    vec![Example {
+        description: "Var value from columns in a dataframe",
+        example: "[[a b]; [6 2] [4 2] [2 2]] | to-df | var",
+        result: Some(
+            NuDataFrame::try_from_columns(vec![
+                Column::new("a".to_string(), vec![Value::test_float(4.0)],),
+                Column::new("b".to_string(), vec![Value::test_float(0.0)],),
+            ])
+            .expect("simple df for test should not fail")
+            .into_value(Span::test_data()),
+        ),
+    },],
     var,
     test_var
 );

crates/nu-command/src/dataframe/lazy/mod.rs

@@ -1,9 +1,9 @@
-mod aggregate;
+pub mod aggregate;
 mod collect;
 mod fetch;
 mod fill_na;
 mod fill_null;
-mod groupby;
+pub mod groupby;
 mod join;
 mod macro_commands;
 mod quantile;

crates/nu-command/src/dataframe/lazy/quantile.rs

@@ -1,9 +1,9 @@
-use crate::dataframe::values::{Column, NuDataFrame, NuExpression, NuLazyFrame};
+use crate::dataframe::values::{Column, NuDataFrame, NuLazyFrame};
 use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::QuantileInterpolOptions;
 
@@ -12,7 +12,7 @@ pub struct LazyQuantile;
 
 impl Command for LazyQuantile {
     fn name(&self) -> &str {
-        "dfr quantile"
+        "quantile"
     }
 
     fn usage(&self) -> &str {
@@ -30,41 +30,26 @@ impl Command for LazyQuantile {
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![
-            Example {
-                description: "quantile value from columns in a dataframe",
-                example: "[[a b]; [6 2] [1 4] [4 1]] | dfr to-df | dfr quantile 0.5",
-                result: Some(
-                    NuDataFrame::try_from_columns(vec![
-                        Column::new("a".to_string(), vec![Value::test_float(4.0)]),
-                        Column::new("b".to_string(), vec![Value::test_float(2.0)]),
-                    ])
-                    .expect("simple df for test should not fail")
-                    .into_value(Span::test_data()),
-                ),
-            },
-            Example {
-                description: "Quantile aggregation for a group by",
-                example: r#"[[a b]; [one 2] [one 4] [two 1]] 
-    | dfr to-df 
-    | dfr group-by a
-    | dfr agg ("b" | dfr quantile 0.5)"#,
-                result: Some(
-                    NuDataFrame::try_from_columns(vec![
-                        Column::new(
-                            "a".to_string(),
-                            vec![Value::test_string("one"), Value::test_string("two")],
-                        ),
-                        Column::new(
-                            "b".to_string(),
-                            vec![Value::test_float(4.0), Value::test_float(1.0)],
-                        ),
-                    ])
-                    .expect("simple df for test should not fail")
-                    .into_value(Span::test_data()),
-                ),
-            },
-        ]
+        vec![Example {
+            description: "quantile value from columns in a dataframe",
+            example: "[[a b]; [6 2] [1 4] [4 1]] | to-df | quantile 0.5",
+            result: Some(
+                NuDataFrame::try_from_columns(vec![
+                    Column::new("a".to_string(), vec![Value::test_float(4.0)]),
+                    Column::new("b".to_string(), vec![Value::test_float(2.0)]),
+                ])
+                .expect("simple df for test should not fail")
+                .into_value(Span::test_data()),
+            ),
+        }]
+    }
+
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
     }
 
     fn run(
@@ -77,27 +62,14 @@ impl Command for LazyQuantile {
         let value = input.into_value(call.head);
         let quantile: f64 = call.req(engine_state, stack, 0)?;
 
-        if NuExpression::can_downcast(&value) {
-            let expr = NuExpression::try_from_value(value)?;
-            let expr: NuExpression = expr
-                .into_polars()
-                .quantile(quantile, QuantileInterpolOptions::default())
-                .into();
+        let lazy = NuLazyFrame::try_from_value(value)?;
+        let lazy = NuLazyFrame::new(
+            lazy.from_eager,
+            lazy.into_polars()
+                .quantile(quantile, QuantileInterpolOptions::default()),
+        );
 
-            Ok(PipelineData::Value(
-                NuExpression::into_value(expr, call.head),
-                None,
-            ))
-        } else {
-            let lazy = NuLazyFrame::try_from_value(value)?;
-            let lazy = NuLazyFrame::new(
-                lazy.from_eager,
-                lazy.into_polars()
-                    .quantile(quantile, QuantileInterpolOptions::default()),
-            );
-
-            Ok(PipelineData::Value(lazy.into_value(call.head)?, None))
-        }
+        Ok(PipelineData::Value(lazy.into_value(call.head)?, None))
     }
 }
 
@@ -105,15 +77,9 @@ impl Command for LazyQuantile {
 mod test {
     use super::super::super::test_dataframe::test_dataframe;
     use super::*;
-    use crate::dataframe::lazy::aggregate::LazyAggregate;
-    use crate::dataframe::lazy::groupby::ToLazyGroupBy;
 
     #[test]
     fn test_examples() {
-        test_dataframe(vec![
-            Box::new(LazyQuantile {}),
-            Box::new(LazyAggregate {}),
-            Box::new(ToLazyGroupBy {}),
-        ])
+        test_dataframe(vec![Box::new(LazyQuantile {})])
     }
 }

crates/nu-command/src/dataframe/lazy/select.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::Expr;
 
@@ -13,7 +13,7 @@ pub struct LazySelect;
 
 impl Command for LazySelect {
     fn name(&self) -> &str {
-        "dfr select"
+        "select"
     }
 
     fn usage(&self) -> &str {
@@ -33,7 +33,7 @@ impl Command for LazySelect {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Select a column from the dataframe",
-            example: "[[a b]; [6 2] [4 2] [2 2]] | dfr to-df | dfr select a",
+            example: "[[a b]; [6 2] [4 2] [2 2]] | to-df | select a",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "a".to_string(),
@@ -45,6 +45,14 @@ impl Command for LazySelect {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/lazy/sort_by_expr.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -12,7 +12,7 @@ pub struct LazySortBy;
 
 impl Command for LazySortBy {
     fn name(&self) -> &str {
-        "dfr sort-by"
+        "sort-by"
     }
 
     fn usage(&self) -> &str {
@@ -39,7 +39,7 @@ impl Command for LazySortBy {
         vec![
             Example {
                 description: "Sort dataframe by one column",
-                example: "[[a b]; [6 2] [1 4] [4 1]] | dfr to-df | dfr sort-by a",
+                example: "[[a b]; [6 2] [1 4] [4 1]] | to-df | sort-by a",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -57,8 +57,7 @@ impl Command for LazySortBy {
             },
             Example {
                 description: "Sort column using two columns",
-                example:
-                    "[[a b]; [6 2] [1 1] [1 4] [2 4]] | dfr to-df | dfr sort-by [a b] -r [false true]",
+                example: "[[a b]; [6 2] [1 1] [1 4] [2 4]] | to-df | sort-by [a b] -r [false true]",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![
                         Column::new(
@@ -87,6 +86,14 @@ impl Command for LazySortBy {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/lazy/to_lazy.rs

@@ -3,7 +3,7 @@ use super::super::values::{NuDataFrame, NuLazyFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Value,
+    Category, Example, PipelineData, ShellError, Signature, Type, Value,
 };
 
 #[derive(Clone)]
@@ -11,7 +11,7 @@ pub struct ToLazyFrame;
 
 impl Command for ToLazyFrame {
     fn name(&self) -> &str {
-        "dfr to-lazy"
+        "to-lazy"
     }
 
     fn usage(&self) -> &str {
@@ -25,11 +25,19 @@ impl Command for ToLazyFrame {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Takes a dictionary and creates a lazy dataframe",
-            example: "[[a b];[1 2] [3 4]] | dfr to-df | dfl to-lazy",
+            example: "[[a b];[1 2] [3 4]] | to-lazy",
             result: None,
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Any
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         _engine_state: &EngineState,

crates/nu-command/src/dataframe/series/all_false.rs

@@ -3,7 +3,7 @@ use super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 
 #[derive(Clone)]
@@ -11,7 +11,7 @@ pub struct AllFalse;
 
 impl Command for AllFalse {
     fn name(&self) -> &str {
-        "dfr all-false"
+        "all-false"
     }
 
     fn usage(&self) -> &str {
@@ -26,7 +26,7 @@ impl Command for AllFalse {
         vec![
             Example {
                 description: "Returns true if all values are false",
-                example: "[false false false] | dfr to-df | dfr all-false",
+                example: "[false false false] | to-df | all-false",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "all_false".to_string(),
@@ -38,9 +38,9 @@ impl Command for AllFalse {
             },
             Example {
                 description: "Checks the result from a comparison",
-                example: r#"let s = ([5 6 2 10] | dfr to-df);
+                example: r#"let s = ([5 6 2 10] | to-df);
     let res = ($s > 9);
-    $res | dfr all-false"#,
+    $res | all-false"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "all_false".to_string(),
@@ -53,6 +53,14 @@ impl Command for AllFalse {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/all_true.rs

@@ -3,7 +3,7 @@ use super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 
 #[derive(Clone)]
@@ -11,7 +11,7 @@ pub struct AllTrue;
 
 impl Command for AllTrue {
     fn name(&self) -> &str {
-        "dfr all-true"
+        "all-true"
     }
 
     fn usage(&self) -> &str {
@@ -26,7 +26,7 @@ impl Command for AllTrue {
         vec![
             Example {
                 description: "Returns true if all values are true",
-                example: "[true true true] | dfr to-df | dfr all-true",
+                example: "[true true true] | to-df | all-true",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "all_true".to_string(),
@@ -38,9 +38,9 @@ impl Command for AllTrue {
             },
             Example {
                 description: "Checks the result from a comparison",
-                example: r#"let s = ([5 6 2 8] | dfr to-df);
+                example: r#"let s = ([5 6 2 8] | to-df);
     let res = ($s > 9);
-    $res | dfr all-true"#,
+    $res | all-true"#,
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "all_true".to_string(),
@@ -53,6 +53,14 @@ impl Command for AllTrue {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/arg_max.rs

@@ -3,7 +3,7 @@ use super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::{IntoSeries, NewChunkedArray, UInt32Chunked};
 
@@ -12,7 +12,7 @@ pub struct ArgMax;
 
 impl Command for ArgMax {
     fn name(&self) -> &str {
-        "dfr arg-max"
+        "arg-max"
     }
 
     fn usage(&self) -> &str {
@@ -26,7 +26,7 @@ impl Command for ArgMax {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Returns index for max value",
-            example: "[1 3 2] | dfr to-df | dfr arg-max",
+            example: "[1 3 2] | to-df | arg-max",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "arg_max".to_string(),
@@ -38,6 +38,14 @@ impl Command for ArgMax {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/arg_min.rs

@@ -3,7 +3,7 @@ use super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::{IntoSeries, NewChunkedArray, UInt32Chunked};
 
@@ -12,7 +12,7 @@ pub struct ArgMin;
 
 impl Command for ArgMin {
     fn name(&self) -> &str {
-        "dfr arg-min"
+        "arg-min"
     }
 
     fn usage(&self) -> &str {
@@ -26,7 +26,7 @@ impl Command for ArgMin {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Returns index for min value",
-            example: "[1 3 2] | dfr to-df | dfr arg-min",
+            example: "[1 3 2] | to-df | arg-min",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "arg_min".to_string(),
@@ -38,6 +38,14 @@ impl Command for ArgMin {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/cumulative.rs

@@ -4,7 +4,8 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Type,
+    Value,
 };
 use polars::prelude::{DataType, IntoSeries};
 
@@ -44,7 +45,7 @@ pub struct Cumulative;
 
 impl Command for Cumulative {
     fn name(&self) -> &str {
-        "dfr cumulative"
+        "cumulative"
     }
 
     fn usage(&self) -> &str {
@@ -61,7 +62,7 @@ impl Command for Cumulative {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Cumulative sum for a series",
-            example: "[1 2 3 4 5] | dfr to-df | dfr cumulative sum",
+            example: "[1 2 3 4 5] | to-df | cumulative sum",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0_cumulative_sum".to_string(),
@@ -79,6 +80,14 @@ impl Command for Cumulative {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/date/as_date.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, SyntaxShape,
+    Category, Example, PipelineData, ShellError, Signature, SyntaxShape, Type,
 };
 use polars::prelude::{IntoSeries, Utf8Methods};
 
@@ -13,7 +13,7 @@ pub struct AsDate;
 
 impl Command for AsDate {
     fn name(&self) -> &str {
-        "dfr as-date"
+        "as-date"
     }
 
     fn usage(&self) -> &str {
@@ -37,11 +37,19 @@ impl Command for AsDate {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Converts string to date",
-            example: r#"["2021-12-30" "2021-12-31"] | dfr to-df | dfr as-datetime "%Y-%m-%d""#,
+            example: r#"["2021-12-30" "2021-12-31"] | to-df | as-datetime "%Y-%m-%d""#,
             result: None,
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/date/as_datetime.rs

@@ -5,7 +5,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::{IntoSeries, TimeUnit, Utf8Methods};
 
@@ -14,7 +14,7 @@ pub struct AsDateTime;
 
 impl Command for AsDateTime {
     fn name(&self) -> &str {
-        "dfr as-datetime"
+        "as-datetime"
     }
 
     fn usage(&self) -> &str {
@@ -46,7 +46,7 @@ impl Command for AsDateTime {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Converts string to datetime",
-            example: r#"["2021-12-30 00:00:00" "2021-12-31 00:00:00"] | dfr to-df | dfr as-datetime "%Y-%m-%d %H:%M:%S""#,
+            example: r#"["2021-12-30 00:00:00" "2021-12-31 00:00:00"] | to-df | as-datetime "%Y-%m-%d %H:%M:%S""#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "datetime".to_string(),
@@ -75,6 +75,14 @@ impl Command for AsDateTime {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/date/get_day.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::{DatetimeMethods, IntoSeries};
 
@@ -12,7 +12,7 @@ pub struct GetDay;
 
 impl Command for GetDay {
     fn name(&self) -> &str {
-        "dfr get-day"
+        "get-day"
     }
 
     fn usage(&self) -> &str {
@@ -27,8 +27,8 @@ impl Command for GetDay {
         vec![Example {
             description: "Returns day from a date",
             example: r#"let dt = ('2020-08-04T16:39:18+00:00' | into datetime -z 'UTC');
-    let df = ([$dt $dt] | dfr to-df);
-    $df | dfr get-day"#,
+    let df = ([$dt $dt] | to-df);
+    $df | get-day"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -40,6 +40,14 @@ impl Command for GetDay {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/date/get_hour.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::{DatetimeMethods, IntoSeries};
 
@@ -12,7 +12,7 @@ pub struct GetHour;
 
 impl Command for GetHour {
     fn name(&self) -> &str {
-        "dfr get-hour"
+        "get-hour"
     }
 
     fn usage(&self) -> &str {
@@ -27,8 +27,8 @@ impl Command for GetHour {
         vec![Example {
             description: "Returns hour from a date",
             example: r#"let dt = ('2020-08-04T16:39:18+00:00' | into datetime -z 'UTC');
-    let df = ([$dt $dt] | dfr to-df);
-    $df | dfr get-hour"#,
+    let df = ([$dt $dt] | to-df);
+    $df | get-hour"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -40,6 +40,14 @@ impl Command for GetHour {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/date/get_minute.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::{DatetimeMethods, IntoSeries};
 
@@ -12,7 +12,7 @@ pub struct GetMinute;
 
 impl Command for GetMinute {
     fn name(&self) -> &str {
-        "dfr get-minute"
+        "get-minute"
     }
 
     fn usage(&self) -> &str {
@@ -27,8 +27,8 @@ impl Command for GetMinute {
         vec![Example {
             description: "Returns minute from a date",
             example: r#"let dt = ('2020-08-04T16:39:18+00:00' | into datetime -z 'UTC');
-    let df = ([$dt $dt] | dfr to-df);
-    $df | dfr get-minute"#,
+    let df = ([$dt $dt] | to-df);
+    $df | get-minute"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -40,6 +40,14 @@ impl Command for GetMinute {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/date/get_month.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::{DatetimeMethods, IntoSeries};
 
@@ -12,7 +12,7 @@ pub struct GetMonth;
 
 impl Command for GetMonth {
     fn name(&self) -> &str {
-        "dfr get-month"
+        "get-month"
     }
 
     fn usage(&self) -> &str {
@@ -27,8 +27,8 @@ impl Command for GetMonth {
         vec![Example {
             description: "Returns month from a date",
             example: r#"let dt = ('2020-08-04T16:39:18+00:00' | into datetime -z 'UTC');
-    let df = ([$dt $dt] | dfr to-df);
-    $df | dfr get-month"#,
+    let df = ([$dt $dt] | to-df);
+    $df | get-month"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -40,6 +40,14 @@ impl Command for GetMonth {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/date/get_nanosecond.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::{DatetimeMethods, IntoSeries};
 
@@ -12,7 +12,7 @@ pub struct GetNanosecond;
 
 impl Command for GetNanosecond {
     fn name(&self) -> &str {
-        "dfr get-nanosecond"
+        "get-nanosecond"
     }
 
     fn usage(&self) -> &str {
@@ -27,8 +27,8 @@ impl Command for GetNanosecond {
         vec![Example {
             description: "Returns nanosecond from a date",
             example: r#"let dt = ('2020-08-04T16:39:18+00:00' | into datetime -z 'UTC');
-    let df = ([$dt $dt] | dfr to-df);
-    $df | dfr get-nanosecond"#,
+    let df = ([$dt $dt] | to-df);
+    $df | get-nanosecond"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -40,6 +40,14 @@ impl Command for GetNanosecond {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/date/get_ordinal.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::{DatetimeMethods, IntoSeries};
 
@@ -12,7 +12,7 @@ pub struct GetOrdinal;
 
 impl Command for GetOrdinal {
     fn name(&self) -> &str {
-        "dfr get-ordinal"
+        "get-ordinal"
     }
 
     fn usage(&self) -> &str {
@@ -27,8 +27,8 @@ impl Command for GetOrdinal {
         vec![Example {
             description: "Returns ordinal from a date",
             example: r#"let dt = ('2020-08-04T16:39:18+00:00' | into datetime -z 'UTC');
-    let df = ([$dt $dt] | dfr to-df);
-    $df | dfr get-ordinal"#,
+    let df = ([$dt $dt] | to-df);
+    $df | get-ordinal"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -40,6 +40,14 @@ impl Command for GetOrdinal {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/date/get_second.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::{DatetimeMethods, IntoSeries};
 
@@ -12,7 +12,7 @@ pub struct GetSecond;
 
 impl Command for GetSecond {
     fn name(&self) -> &str {
-        "dfr get-second"
+        "get-second"
     }
 
     fn usage(&self) -> &str {
@@ -27,8 +27,8 @@ impl Command for GetSecond {
         vec![Example {
             description: "Returns second from a date",
             example: r#"let dt = ('2020-08-04T16:39:18+00:00' | into datetime -z 'UTC');
-    let df = ([$dt $dt] | dfr to-df);
-    $df | dfr get-second"#,
+    let df = ([$dt $dt] | to-df);
+    $df | get-second"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -40,6 +40,14 @@ impl Command for GetSecond {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/date/get_week.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::{DatetimeMethods, IntoSeries};
 
@@ -12,7 +12,7 @@ pub struct GetWeek;
 
 impl Command for GetWeek {
     fn name(&self) -> &str {
-        "dfr get-week"
+        "get-week"
     }
 
     fn usage(&self) -> &str {
@@ -27,8 +27,8 @@ impl Command for GetWeek {
         vec![Example {
             description: "Returns week from a date",
             example: r#"let dt = ('2020-08-04T16:39:18+00:00' | into datetime -z 'UTC');
-    let df = ([$dt $dt] | dfr to-df);
-    $df | dfr get-week"#,
+    let df = ([$dt $dt] | to-df);
+    $df | get-week"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -40,6 +40,14 @@ impl Command for GetWeek {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/date/get_weekday.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::{DatetimeMethods, IntoSeries};
 
@@ -12,7 +12,7 @@ pub struct GetWeekDay;
 
 impl Command for GetWeekDay {
     fn name(&self) -> &str {
-        "dfr get-weekday"
+        "get-weekday"
     }
 
     fn usage(&self) -> &str {
@@ -27,8 +27,8 @@ impl Command for GetWeekDay {
         vec![Example {
             description: "Returns weekday from a date",
             example: r#"let dt = ('2020-08-04T16:39:18+00:00' | into datetime -z 'UTC');
-    let df = ([$dt $dt] | dfr to-df);
-    $df | dfr get-weekday"#,
+    let df = ([$dt $dt] | to-df);
+    $df | get-weekday"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -40,6 +40,14 @@ impl Command for GetWeekDay {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/date/get_year.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::{DatetimeMethods, IntoSeries};
 
@@ -12,7 +12,7 @@ pub struct GetYear;
 
 impl Command for GetYear {
     fn name(&self) -> &str {
-        "dfr get-year"
+        "get-year"
     }
 
     fn usage(&self) -> &str {
@@ -27,8 +27,8 @@ impl Command for GetYear {
         vec![Example {
             description: "Returns year from a date",
             example: r#"let dt = ('2020-08-04T16:39:18+00:00' | into datetime -z 'UTC');
-    let df = ([$dt $dt] | dfr to-df);
-    $df | dfr get-year"#,
+    let df = ([$dt $dt] | to-df);
+    $df | get-year"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -40,6 +40,14 @@ impl Command for GetYear {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/indexes/arg_sort.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::{IntoSeries, SortOptions};
 
@@ -12,7 +12,7 @@ pub struct ArgSort;
 
 impl Command for ArgSort {
     fn name(&self) -> &str {
-        "dfr arg-sort"
+        "arg-sort"
     }
 
     fn usage(&self) -> &str {
@@ -30,7 +30,7 @@ impl Command for ArgSort {
         vec![
             Example {
                 description: "Returns indexes for a sorted series",
-                example: "[1 2 2 3 3] | dfr to-df | dfr arg-sort",
+                example: "[1 2 2 3 3] | to-df | arg-sort",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "arg_sort".to_string(),
@@ -48,7 +48,7 @@ impl Command for ArgSort {
             },
             Example {
                 description: "Returns indexes for a sorted series",
-                example: "[1 2 2 3 3] | dfr to-df | dfr arg-sort -r",
+                example: "[1 2 2 3 3] | to-df | arg-sort -r",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "arg_sort".to_string(),
@@ -67,6 +67,14 @@ impl Command for ArgSort {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/indexes/arg_true.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -12,7 +12,7 @@ pub struct ArgTrue;
 
 impl Command for ArgTrue {
     fn name(&self) -> &str {
-        "dfr arg-true"
+        "arg-true"
     }
 
     fn usage(&self) -> &str {
@@ -26,7 +26,7 @@ impl Command for ArgTrue {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Returns indexes where values are true",
-            example: "[false true false] | dfr to-df | dfr arg-true",
+            example: "[false true false] | to-df | arg-true",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "arg_true".to_string(),
@@ -38,6 +38,14 @@ impl Command for ArgTrue {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/indexes/arg_unique.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -12,7 +12,7 @@ pub struct ArgUnique;
 
 impl Command for ArgUnique {
     fn name(&self) -> &str {
-        "dfr arg-unique"
+        "arg-unique"
     }
 
     fn usage(&self) -> &str {
@@ -26,7 +26,7 @@ impl Command for ArgUnique {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Returns indexes for unique values",
-            example: "[1 2 2 3 3] | dfr to-df | dfr arg-unique",
+            example: "[1 2 2 3 3] | to-df | arg-unique",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "arg_unique".to_string(),
@@ -38,6 +38,14 @@ impl Command for ArgUnique {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/indexes/set_with_idx.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::{ChunkSet, DataType, IntoSeries};
 
@@ -13,7 +13,7 @@ pub struct SetWithIndex;
 
 impl Command for SetWithIndex {
     fn name(&self) -> &str {
-        "dfr set-with-idx"
+        "set-with-idx"
     }
 
     fn usage(&self) -> &str {
@@ -35,9 +35,9 @@ impl Command for SetWithIndex {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Set value in selected rows from series",
-            example: r#"let series = ([4 1 5 2 4 3] | dfr to-df);
-    let indices = ([0 2] | dfr to-df);
-    $series | dfr set-with-idx 6 -i $indices"#,
+            example: r#"let series = ([4 1 5 2 4 3] | to-df);
+    let indices = ([0 2] | to-df);
+    $series | set-with-idx 6 -i $indices"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -56,6 +56,14 @@ impl Command for SetWithIndex {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/masks/is_duplicated.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -12,7 +12,7 @@ pub struct IsDuplicated;
 
 impl Command for IsDuplicated {
     fn name(&self) -> &str {
-        "dfr is-duplicated"
+        "is-duplicated"
     }
 
     fn usage(&self) -> &str {
@@ -26,7 +26,7 @@ impl Command for IsDuplicated {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Create mask indicating duplicated values",
-            example: "[5 6 6 6 8 8 8] | dfr to-df | dfr is-duplicated",
+            example: "[5 6 6 6 8 8 8] | to-df | is-duplicated",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "is_duplicated".to_string(),
@@ -46,6 +46,14 @@ impl Command for IsDuplicated {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/masks/is_in.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -13,7 +13,7 @@ pub struct IsIn;
 
 impl Command for IsIn {
     fn name(&self) -> &str {
-        "dfr is-in"
+        "is-in"
     }
 
     fn usage(&self) -> &str {
@@ -29,8 +29,8 @@ impl Command for IsIn {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Checks if elements from a series are contained in right series",
-            example: r#"let other = ([1 3 6] | dfr to-df);
-    [5 6 6 6 8 8 8] | dfr to-df | dfr is-in $other"#,
+            example: r#"let other = ([1 3 6] | to-df);
+    [5 6 6 6 8 8 8] | to-df | is-in $other"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "is_in".to_string(),
@@ -50,6 +50,14 @@ impl Command for IsIn {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/masks/is_not_null.rs

@@ -1,9 +1,8 @@
 use super::super::super::values::{Column, NuDataFrame};
-use crate::dataframe::values::NuExpression;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -12,44 +11,45 @@ pub struct IsNotNull;
 
 impl Command for IsNotNull {
     fn name(&self) -> &str {
-        "dfr is-not-null"
+        "is-not-null"
     }
 
     fn usage(&self) -> &str {
-        "Creates mask where value is not null or creates a is-not-null expression"
+        "Creates mask where value is not null"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("dataframe or lazyframe".into()))
+        Signature::build(self.name()).category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![
-            Example {
-                description: "Create mask where values are not null",
-                example: r#"let s = ([5 6 0 8] | dfr to-df);
+        vec![Example {
+            description: "Create mask where values are not null",
+            example: r#"let s = ([5 6 0 8] | to-df);
     let res = ($s / $s);
-    $res | dfr is-not-null"#,
-                result: Some(
-                    NuDataFrame::try_from_columns(vec![Column::new(
-                        "is_not_null".to_string(),
-                        vec![
-                            Value::test_bool(true),
-                            Value::test_bool(true),
-                            Value::test_bool(false),
-                            Value::test_bool(true),
-                        ],
-                    )])
-                    .expect("simple df for test should not fail")
-                    .into_value(Span::test_data()),
-                ),
-            },
-            Example {
-                description: "Creates a is not null expression from a column",
-                example: "dfr col a | dfr is-not-null",
-                result: None,
-            },
-        ]
+    $res | is-not-null"#,
+            result: Some(
+                NuDataFrame::try_from_columns(vec![Column::new(
+                    "is_not_null".to_string(),
+                    vec![
+                        Value::test_bool(true),
+                        Value::test_bool(true),
+                        Value::test_bool(false),
+                        Value::test_bool(true),
+                    ],
+                )])
+                .expect("simple df for test should not fail")
+                .into_value(Span::test_data()),
+            ),
+        }]
+    }
+
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
     }
 
     fn run(
@@ -59,27 +59,8 @@ impl Command for IsNotNull {
         call: &Call,
         input: PipelineData,
     ) -> Result<PipelineData, ShellError> {
-        let value = input.into_value(call.head);
-
-        if NuExpression::can_downcast(&value) {
-            let expr = NuExpression::try_from_value(value)?;
-            let expr: NuExpression = expr.into_polars().is_not_null().into();
-
-            Ok(PipelineData::Value(
-                NuExpression::into_value(expr, call.head),
-                None,
-            ))
-        } else if NuDataFrame::can_downcast(&value) {
-            let df = NuDataFrame::try_from_value(value)?;
-            command(engine_state, stack, call, df)
-        } else {
-            Err(ShellError::CantConvert(
-                "expression or query".into(),
-                value.get_type().to_string(),
-                value.span()?,
-                None,
-            ))
-        }
+        let df = NuDataFrame::try_from_pipeline(input, call.head)?;
+        command(engine_state, stack, call, df)
     }
 }
 

crates/nu-command/src/dataframe/series/masks/is_null.rs

@@ -1,9 +1,8 @@
 use super::super::super::values::{Column, NuDataFrame};
-use crate::dataframe::values::NuExpression;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -12,44 +11,45 @@ pub struct IsNull;
 
 impl Command for IsNull {
     fn name(&self) -> &str {
-        "dfr is-null"
+        "is-null"
     }
 
     fn usage(&self) -> &str {
-        "Creates mask where value is null or creates a is-null expression"
+        "Creates mask where value is null"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("dataframe or expression".into()))
+        Signature::build(self.name()).category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![
-            Example {
-                description: "Create mask where values are null",
-                example: r#"let s = ([5 6 0 8] | dfr to-df);
+        vec![Example {
+            description: "Create mask where values are null",
+            example: r#"let s = ([5 6 0 8] | to-df);
     let res = ($s / $s);
-    $res | dfr is-null"#,
-                result: Some(
-                    NuDataFrame::try_from_columns(vec![Column::new(
-                        "is_null".to_string(),
-                        vec![
-                            Value::test_bool(false),
-                            Value::test_bool(false),
-                            Value::test_bool(true),
-                            Value::test_bool(false),
-                        ],
-                    )])
-                    .expect("simple df for test should not fail")
-                    .into_value(Span::test_data()),
-                ),
-            },
-            Example {
-                description: "Creates a is not null expression from a column",
-                example: "dfr col a | dfr is-null",
-                result: None,
-            },
-        ]
+    $res | is-null"#,
+            result: Some(
+                NuDataFrame::try_from_columns(vec![Column::new(
+                    "is_null".to_string(),
+                    vec![
+                        Value::test_bool(false),
+                        Value::test_bool(false),
+                        Value::test_bool(true),
+                        Value::test_bool(false),
+                    ],
+                )])
+                .expect("simple df for test should not fail")
+                .into_value(Span::test_data()),
+            ),
+        }]
+    }
+
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
     }
 
     fn run(
@@ -59,27 +59,8 @@ impl Command for IsNull {
         call: &Call,
         input: PipelineData,
     ) -> Result<PipelineData, ShellError> {
-        let value = input.into_value(call.head);
-
-        if NuExpression::can_downcast(&value) {
-            let expr = NuExpression::try_from_value(value)?;
-            let expr: NuExpression = expr.into_polars().is_null().into();
-
-            Ok(PipelineData::Value(
-                NuExpression::into_value(expr, call.head),
-                None,
-            ))
-        } else if NuDataFrame::can_downcast(&value) {
-            let df = NuDataFrame::try_from_value(value)?;
-            command(engine_state, stack, call, df)
-        } else {
-            Err(ShellError::CantConvert(
-                "expression or query".into(),
-                value.get_type().to_string(),
-                value.span()?,
-                None,
-            ))
-        }
+        let df = NuDataFrame::try_from_pipeline(input, call.head)?;
+        command(engine_state, stack, call, df)
     }
 }
 

crates/nu-command/src/dataframe/series/masks/is_unique.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -12,7 +12,7 @@ pub struct IsUnique;
 
 impl Command for IsUnique {
     fn name(&self) -> &str {
-        "dfr is-unique"
+        "is-unique"
     }
 
     fn usage(&self) -> &str {
@@ -26,7 +26,7 @@ impl Command for IsUnique {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Create mask indicating unique values",
-            example: "[5 6 6 6 8 8 8] | dfr to-df | dfr is-unique",
+            example: "[5 6 6 6 8 8 8] | to-df | is-unique",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "is_unique".to_string(),
@@ -46,6 +46,14 @@ impl Command for IsUnique {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/masks/not.rs

@@ -1,9 +1,8 @@
 use super::super::super::values::{Column, NuDataFrame};
-use crate::dataframe::values::NuExpression;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -14,41 +13,42 @@ pub struct NotSeries;
 
 impl Command for NotSeries {
     fn name(&self) -> &str {
-        "dfr not"
+        "df-not"
     }
 
     fn usage(&self) -> &str {
-        "Inverts boolean mask or creates a not expression"
+        "Inverts boolean mask"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("dataframe or lazyframes".into()))
+        Signature::build(self.name()).category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![
-            Example {
-                description: "Inverts boolean mask",
-                example: "[true false true] | dfr to-df | dfr not",
-                result: Some(
-                    NuDataFrame::try_from_columns(vec![Column::new(
-                        "0".to_string(),
-                        vec![
-                            Value::test_bool(false),
-                            Value::test_bool(true),
-                            Value::test_bool(false),
-                        ],
-                    )])
-                    .expect("simple df for test should not fail")
-                    .into_value(Span::test_data()),
-                ),
-            },
-            Example {
-                description: "Creates a not expression from a column",
-                example: "((dfr col a) > 2) | dfr not",
-                result: None,
-            },
-        ]
+        vec![Example {
+            description: "Inverts boolean mask",
+            example: "[true false true] | to-df | df-not",
+            result: Some(
+                NuDataFrame::try_from_columns(vec![Column::new(
+                    "0".to_string(),
+                    vec![
+                        Value::test_bool(false),
+                        Value::test_bool(true),
+                        Value::test_bool(false),
+                    ],
+                )])
+                .expect("simple df for test should not fail")
+                .into_value(Span::test_data()),
+            ),
+        }]
+    }
+
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
     }
 
     fn run(
@@ -58,27 +58,8 @@ impl Command for NotSeries {
         call: &Call,
         input: PipelineData,
     ) -> Result<PipelineData, ShellError> {
-        let value = input.into_value(call.head);
-
-        if NuExpression::can_downcast(&value) {
-            let expr = NuExpression::try_from_value(value)?;
-            let expr: NuExpression = expr.into_polars().is_null().into();
-
-            Ok(PipelineData::Value(
-                NuExpression::into_value(expr, call.head),
-                None,
-            ))
-        } else if NuDataFrame::can_downcast(&value) {
-            let df = NuDataFrame::try_from_value(value)?;
-            command(engine_state, stack, call, df)
-        } else {
-            Err(ShellError::CantConvert(
-                "expression or query".into(),
-                value.get_type().to_string(),
-                value.span()?,
-                None,
-            ))
-        }
+        let df = NuDataFrame::try_from_pipeline(input, call.head)?;
+        command(engine_state, stack, call, df)
     }
 }
 

crates/nu-command/src/dataframe/series/masks/set.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::{ChunkSet, DataType, IntoSeries};
 
@@ -13,7 +13,7 @@ pub struct SetSeries;
 
 impl Command for SetSeries {
     fn name(&self) -> &str {
-        "dfr set"
+        "set"
     }
 
     fn usage(&self) -> &str {
@@ -35,9 +35,9 @@ impl Command for SetSeries {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Shifts the values by a given period",
-            example: r#"let s = ([1 2 2 3 3] | dfr to-df | dfr shift 2);
-    let mask = ($s | dfr is-null);
-    $s | dfr set 0 --mask $mask"#,
+            example: r#"let s = ([1 2 2 3 3] | to-df | shift 2);
+    let mask = ($s | is-null);
+    $s | set 0 --mask $mask"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -55,6 +55,14 @@ impl Command for SetSeries {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/n_null.rs

@@ -3,7 +3,7 @@ use super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 
 #[derive(Clone)]
@@ -11,7 +11,7 @@ pub struct NNull;
 
 impl Command for NNull {
     fn name(&self) -> &str {
-        "dfr count-null"
+        "count-null"
     }
 
     fn usage(&self) -> &str {
@@ -25,8 +25,8 @@ impl Command for NNull {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Counts null values",
-            example: r#"let s = ([1 1 0 0 3 3 4] | dfr to-df);
-    ($s / $s) | dfr count-null"#,
+            example: r#"let s = ([1 1 0 0 3 3 4] | to-df);
+    ($s / $s) | count-null"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "count_null".to_string(),
@@ -38,6 +38,14 @@ impl Command for NNull {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/n_unique.rs

@@ -1,9 +1,8 @@
 use super::super::values::{Column, NuDataFrame};
-use crate::dataframe::values::NuExpression;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 
 #[derive(Clone)]
@@ -11,37 +10,38 @@ pub struct NUnique;
 
 impl Command for NUnique {
     fn name(&self) -> &str {
-        "dfr n-unique"
+        "n-unique"
     }
 
     fn usage(&self) -> &str {
-        "Counts unique values or creates a n-unique expression"
+        "Counts unique values"
     }
 
     fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Custom("dataframe or expression".into()))
+        Signature::build(self.name()).category(Category::Custom("dataframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
-        vec![
-            Example {
-                description: "Counts unique values",
-                example: "[1 1 2 2 3 3 4] | dfr to-df | dfr n-unique",
-                result: Some(
-                    NuDataFrame::try_from_columns(vec![Column::new(
-                        "count_unique".to_string(),
-                        vec![Value::test_int(4)],
-                    )])
-                    .expect("simple df for test should not fail")
-                    .into_value(Span::test_data()),
-                ),
-            },
-            Example {
-                description: "Creates a is n-unique expression from a column",
-                example: "dfr col a | dfr n-unique",
-                result: None,
-            },
-        ]
+        vec![Example {
+            description: "Counts unique values",
+            example: "[1 1 2 2 3 3 4] | to-df | n-unique",
+            result: Some(
+                NuDataFrame::try_from_columns(vec![Column::new(
+                    "count_unique".to_string(),
+                    vec![Value::test_int(4)],
+                )])
+                .expect("simple df for test should not fail")
+                .into_value(Span::test_data()),
+            ),
+        }]
+    }
+
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
     }
 
     fn run(
@@ -51,27 +51,8 @@ impl Command for NUnique {
         call: &Call,
         input: PipelineData,
     ) -> Result<PipelineData, ShellError> {
-        let value = input.into_value(call.head);
-
-        if NuExpression::can_downcast(&value) {
-            let expr = NuExpression::try_from_value(value)?;
-            let expr: NuExpression = expr.into_polars().n_unique().into();
-
-            Ok(PipelineData::Value(
-                NuExpression::into_value(expr, call.head),
-                None,
-            ))
-        } else if NuDataFrame::can_downcast(&value) {
-            let df = NuDataFrame::try_from_value(value)?;
-            command(engine_state, stack, call, df)
-        } else {
-            Err(ShellError::CantConvert(
-                "expression or query".into(),
-                value.get_type().to_string(),
-                value.span()?,
-                None,
-            ))
-        }
+        let df = NuDataFrame::try_from_pipeline(input, call.head)?;
+        command(engine_state, stack, call, df)
     }
 }
 

crates/nu-command/src/dataframe/series/rolling.rs

@@ -4,7 +4,8 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Spanned, SyntaxShape, Type,
+    Value,
 };
 use polars::prelude::{DataType, IntoSeries, RollingOptions};
 
@@ -47,7 +48,7 @@ pub struct Rolling;
 
 impl Command for Rolling {
     fn name(&self) -> &str {
-        "dfr rolling"
+        "rolling"
     }
 
     fn usage(&self) -> &str {
@@ -65,7 +66,7 @@ impl Command for Rolling {
         vec![
             Example {
                 description: "Rolling sum for a series",
-                example: "[1 2 3 4 5] | dfr to-df | dfr rolling sum 2 | dfr drop-nulls",
+                example: "[1 2 3 4 5] | to-df | rolling sum 2 | drop-nulls",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "0_rolling_sum".to_string(),
@@ -82,7 +83,7 @@ impl Command for Rolling {
             },
             Example {
                 description: "Rolling max for a series",
-                example: "[1 2 3 4 5] | dfr to-df | dfr rolling max 2 | dfr drop-nulls",
+                example: "[1 2 3 4 5] | to-df | rolling max 2 | drop-nulls",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "0_rolling_max".to_string(),
@@ -100,6 +101,14 @@ impl Command for Rolling {
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/shift.rs

@@ -6,7 +6,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 
 #[derive(Clone)]
@@ -14,7 +14,7 @@ pub struct Shift;
 
 impl Command for Shift {
     fn name(&self) -> &str {
-        "dfr shift"
+        "shift"
     }
 
     fn usage(&self) -> &str {
@@ -36,7 +36,7 @@ impl Command for Shift {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Shifts the values by a given period",
-            example: "[1 2 2 3 3] | dfr to-df | dfr shift 2 | dfr drop-nulls",
+            example: "[1 2 2 3 3] | to-df | shift 2 | drop-nulls",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -48,6 +48,14 @@ impl Command for Shift {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,
@@ -60,16 +68,9 @@ impl Command for Shift {
         if NuLazyFrame::can_downcast(&value) {
             let df = NuLazyFrame::try_from_value(value)?;
             command_lazy(engine_state, stack, call, df)
-        } else if NuDataFrame::can_downcast(&value) {
+        } else {
             let df = NuDataFrame::try_from_value(value)?;
             command_eager(engine_state, stack, call, df)
-        } else {
-            Err(ShellError::CantConvert(
-                "expression or query".into(),
-                value.get_type().to_string(),
-                value.span()?,
-                None,
-            ))
         }
     }
 }

crates/nu-command/src/dataframe/series/string/concatenate.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -13,7 +13,7 @@ pub struct Concatenate;
 
 impl Command for Concatenate {
     fn name(&self) -> &str {
-        "dfr concatenate"
+        "concatenate"
     }
 
     fn usage(&self) -> &str {
@@ -33,8 +33,8 @@ impl Command for Concatenate {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Concatenate string",
-            example: r#"let other = ([za xs cd] | dfr to-df);
-    [abc abc abc] | dfr to-df | dfr concatenate $other"#,
+            example: r#"let other = ([za xs cd] | to-df);
+    [abc abc abc] | to-df | concatenate $other"#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -50,6 +50,14 @@ impl Command for Concatenate {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/string/contains.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -13,7 +13,7 @@ pub struct Contains;
 
 impl Command for Contains {
     fn name(&self) -> &str {
-        "dfr contains"
+        "contains"
     }
 
     fn usage(&self) -> &str {
@@ -33,7 +33,7 @@ impl Command for Contains {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Returns boolean indicating if pattern was found",
-            example: "[abc acb acb] | dfr to-df | dfr contains ab",
+            example: "[abc acb acb] | to-df | contains ab",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -49,6 +49,14 @@ impl Command for Contains {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/string/replace.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -13,7 +13,7 @@ pub struct Replace;
 
 impl Command for Replace {
     fn name(&self) -> &str {
-        "dfr replace"
+        "replace"
     }
 
     fn usage(&self) -> &str {
@@ -40,7 +40,7 @@ impl Command for Replace {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Replaces string",
-            example: "[abc abc abc] | dfr to-df | dfr replace -p ab -r AB",
+            example: "[abc abc abc] | to-df | replace -p ab -r AB",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -56,6 +56,14 @@ impl Command for Replace {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/string/replace_all.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -13,7 +13,7 @@ pub struct ReplaceAll;
 
 impl Command for ReplaceAll {
     fn name(&self) -> &str {
-        "dfr replace-all"
+        "replace-all"
     }
 
     fn usage(&self) -> &str {
@@ -40,7 +40,7 @@ impl Command for ReplaceAll {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Replaces string",
-            example: "[abac abac abac] | dfr to-df | dfr replace-all -p a -r A",
+            example: "[abac abac abac] | to-df | replace-all -p a -r A",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -56,6 +56,14 @@ impl Command for ReplaceAll {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/string/str_lengths.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -12,7 +12,7 @@ pub struct StrLengths;
 
 impl Command for StrLengths {
     fn name(&self) -> &str {
-        "dfr str-lengths"
+        "str-lengths"
     }
 
     fn usage(&self) -> &str {
@@ -26,7 +26,7 @@ impl Command for StrLengths {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Returns string lengths",
-            example: "[a ab abc] | dfr to-df | dfr str-lengths",
+            example: "[a ab abc] | to-df | str-lengths",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -38,6 +38,14 @@ impl Command for StrLengths {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/string/str_slice.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -13,7 +13,7 @@ pub struct StrSlice;
 
 impl Command for StrSlice {
     fn name(&self) -> &str {
-        "dfr str-slice"
+        "str-slice"
     }
 
     fn usage(&self) -> &str {
@@ -30,7 +30,7 @@ impl Command for StrSlice {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Creates slices from the strings",
-            example: "[abcded abc321 abc123] | dfr to-df | dfr str-slice 1 -l 2",
+            example: "[abcded abc321 abc123] | to-df | str-slice 1 -l 2",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -46,6 +46,14 @@ impl Command for StrSlice {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/string/strftime.rs

@@ -4,7 +4,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -13,7 +13,7 @@ pub struct StrFTime;
 
 impl Command for StrFTime {
     fn name(&self) -> &str {
-        "dfr strftime"
+        "strftime"
     }
 
     fn usage(&self) -> &str {
@@ -30,8 +30,8 @@ impl Command for StrFTime {
         vec![Example {
             description: "Formats date",
             example: r#"let dt = ('2020-08-04T16:39:18+00:00' | into datetime -z 'UTC');
-    let df = ([$dt $dt] | dfr to-df);
-    $df | dfr strftime "%Y/%m/%d""#,
+    let df = ([$dt $dt] | to-df);
+    $df | strftime "%Y/%m/%d""#,
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -46,6 +46,14 @@ impl Command for StrFTime {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/string/to_lowercase.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -12,7 +12,7 @@ pub struct ToLowerCase;
 
 impl Command for ToLowerCase {
     fn name(&self) -> &str {
-        "dfr to-lowercase"
+        "to-lowercase"
     }
 
     fn usage(&self) -> &str {
@@ -26,7 +26,7 @@ impl Command for ToLowerCase {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Modifies strings to lowercase",
-            example: "[Abc aBc abC] | dfr to-df | dfr to-lowercase",
+            example: "[Abc aBc abC] | to-df | to-lowercase",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -42,6 +42,14 @@ impl Command for ToLowerCase {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/string/to_uppercase.rs

@@ -3,7 +3,7 @@ use super::super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 use polars::prelude::IntoSeries;
 
@@ -12,7 +12,7 @@ pub struct ToUpperCase;
 
 impl Command for ToUpperCase {
     fn name(&self) -> &str {
-        "dfr to-uppercase"
+        "to-uppercase"
     }
 
     fn usage(&self) -> &str {
@@ -26,7 +26,7 @@ impl Command for ToUpperCase {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Modifies strings to uppercase",
-            example: "[Abc aBc abC] | dfr to-df | dfr to-uppercase",
+            example: "[Abc aBc abC] | to-df | to-uppercase",
             result: Some(
                 NuDataFrame::try_from_columns(vec![Column::new(
                     "0".to_string(),
@@ -42,6 +42,14 @@ impl Command for ToUpperCase {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/series/unique.rs

@@ -6,7 +6,7 @@ use nu_engine::CallExt;
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, SyntaxShape, Type, Value,
 };
 use polars::prelude::{IntoSeries, UniqueKeepStrategy};
 
@@ -15,11 +15,11 @@ pub struct Unique;
 
 impl Command for Unique {
     fn name(&self) -> &str {
-        "dfr unique"
+        "unique"
     }
 
     fn usage(&self) -> &str {
-        "Returns unique values from a series"
+        "Returns unique values from a dataframe"
     }
 
     fn signature(&self) -> Signature {
@@ -40,14 +40,14 @@ impl Command for Unique {
                 "Keep the same order as the original DataFrame (lazy df)",
                 Some('k'),
             )
-            .category(Category::Custom("dataframe or expression".into()))
+            .category(Category::Custom("dataframe or lazyframe".into()))
     }
 
     fn examples(&self) -> Vec<Example> {
         vec![
             Example {
                 description: "Returns unique values from a series",
-                example: "[2 2 2 2 2] | dfr to-df | dfr unique",
+                example: "[2 2 2 2 2] | to-df | unique",
                 result: Some(
                     NuDataFrame::try_from_columns(vec![Column::new(
                         "0".to_string(),
@@ -59,12 +59,20 @@ impl Command for Unique {
             },
             Example {
                 description: "Creates a is unique expression from a column",
-                example: "dfr col a | dfr unique",
+                example: "col a | unique",
                 result: None,
             },
         ]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,
@@ -77,16 +85,9 @@ impl Command for Unique {
         if NuLazyFrame::can_downcast(&value) {
             let df = NuLazyFrame::try_from_value(value)?;
             command_lazy(engine_state, stack, call, df)
-        } else if NuDataFrame::can_downcast(&value) {
+        } else {
             let df = NuDataFrame::try_from_value(value)?;
             command_eager(engine_state, stack, call, df)
-        } else {
-            Err(ShellError::CantConvert(
-                "expression or query".into(),
-                value.get_type().to_string(),
-                value.span()?,
-                None,
-            ))
         }
     }
 }

crates/nu-command/src/dataframe/series/value_counts.rs

@@ -3,7 +3,7 @@ use super::super::values::{Column, NuDataFrame};
 use nu_protocol::{
     ast::Call,
     engine::{Command, EngineState, Stack},
-    Category, Example, PipelineData, ShellError, Signature, Span, Value,
+    Category, Example, PipelineData, ShellError, Signature, Span, Type, Value,
 };
 
 #[derive(Clone)]
@@ -11,7 +11,7 @@ pub struct ValueCount;
 
 impl Command for ValueCount {
     fn name(&self) -> &str {
-        "dfr value-counts"
+        "value-counts"
     }
 
     fn usage(&self) -> &str {
@@ -25,7 +25,7 @@ impl Command for ValueCount {
     fn examples(&self) -> Vec<Example> {
         vec![Example {
             description: "Calculates value counts",
-            example: "[5 5 5 5 6 6] | dfr to-df | dfr value-counts",
+            example: "[5 5 5 5 6 6] | to-df | value-counts",
             result: Some(
                 NuDataFrame::try_from_columns(vec![
                     Column::new(
@@ -43,6 +43,14 @@ impl Command for ValueCount {
         }]
     }
 
+    fn input_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
+    fn output_type(&self) -> Type {
+        Type::Custom("dataframe".into())
+    }
+
     fn run(
         &self,
         engine_state: &EngineState,

crates/nu-command/src/dataframe/test_dataframe.rs

@@ -6,6 +6,7 @@ use nu_protocol::{
 };
 
 use super::eager::ToDataFrame;
+use super::expressions::ExprCol;
 use super::lazy::{LazyCollect, ToLazyFrame};
 use crate::Let;
 
@@ -26,6 +27,7 @@ pub fn test_dataframe(cmds: Vec<Box<dyn Command + 'static>>) {
         working_set.add_decl(Box::new(ToDataFrame));
         working_set.add_decl(Box::new(ToLazyFrame));
         working_set.add_decl(Box::new(LazyCollect));
+        working_set.add_decl(Box::new(ExprCol));
 
         // Adding the command that is being tested to the working set
         for cmd in cmds {

crates/nu-command/src/dataframe/values/nu_expression/mod.rs

@@ -174,7 +174,16 @@ pub fn expr_to_value(expr: &Expr, span: Span) -> Value {
     let cols = vec!["expr".to_string(), "value".to_string()];
 
     match expr {
-        Expr::Not(_) => todo!(),
+        Expr::Not(expr) => {
+            let expr = expr_to_value(expr.as_ref(), span);
+            let cols = vec!["expr".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr],
+                span,
+            }
+        }
         Expr::Alias(expr, alias) => {
             let expr = expr_to_value(expr.as_ref(), span);
             let alias = Value::String {
@@ -182,7 +191,7 @@ pub fn expr_to_value(expr: &Expr, span: Span) -> Value {
                 span,
             };
 
-            let cols = vec!["expr".to_string(), "alias".to_string()];
+            let cols = vec!["expr".into(), "alias".into()];
 
             Value::Record {
                 cols,
@@ -192,7 +201,7 @@ pub fn expr_to_value(expr: &Expr, span: Span) -> Value {
         }
         Expr::Column(name) => {
             let expr_type = Value::String {
-                val: "column".into(),
+                val: "column".to_string(),
                 span,
             };
             let value = Value::String {
@@ -222,7 +231,6 @@ pub fn expr_to_value(expr: &Expr, span: Span) -> Value {
             let vals = vec![expr_type, value];
             Value::Record { cols, vals, span }
         }
-        Expr::DtypeColumn(_) => todo!(),
         Expr::Literal(literal) => {
             let expr_type = Value::String {
                 val: "literal".into(),
@@ -245,7 +253,7 @@ pub fn expr_to_value(expr: &Expr, span: Span) -> Value {
                 span,
             };
 
-            let cols = vec!["left".to_string(), "op".to_string(), "right".to_string()];
+            let cols = vec!["left".into(), "op".into(), "right".into()];
 
             Value::Record {
                 cols,
@@ -262,11 +270,7 @@ pub fn expr_to_value(expr: &Expr, span: Span) -> Value {
             let truthy = expr_to_value(truthy.as_ref(), span);
             let falsy = expr_to_value(falsy.as_ref(), span);
 
-            let cols = vec![
-                "predicate".to_string(),
-                "truthy".to_string(),
-                "falsy".to_string(),
-            ];
+            let cols = vec!["predicate".into(), "truthy".into(), "falsy".into()];
 
             Value::Record {
                 cols,
@@ -289,7 +293,29 @@ pub fn expr_to_value(expr: &Expr, span: Span) -> Value {
                 | AggExpr::AggGroups(expr)
                 | AggExpr::Std(expr)
                 | AggExpr::Var(expr) => expr_to_value(expr.as_ref(), span),
-                AggExpr::Quantile { .. } => todo!(),
+                AggExpr::Quantile {
+                    expr,
+                    quantile,
+                    interpol,
+                } => {
+                    let expr = expr_to_value(expr.as_ref(), span);
+                    let quantile = Value::Float {
+                        val: *quantile,
+                        span,
+                    };
+                    let interpol = Value::String {
+                        val: format!("{:?}", interpol),
+                        span,
+                    };
+
+                    let cols = vec!["expr".into(), "quantile".into(), "interpol".into()];
+
+                    Value::Record {
+                        cols,
+                        vals: vec![expr, quantile, interpol],
+                        span,
+                    }
+                }
             };
 
             let expr_type = Value::String {
@@ -300,27 +326,371 @@ pub fn expr_to_value(expr: &Expr, span: Span) -> Value {
             let vals = vec![expr_type, value];
             Value::Record { cols, vals, span }
         }
-        Expr::IsNotNull(_) => todo!(),
-        Expr::IsNull(_) => todo!(),
-        Expr::Cast { .. } => todo!(),
-        Expr::Sort { .. } => todo!(),
-        Expr::Take { .. } => todo!(),
-        Expr::SortBy { .. } => todo!(),
-        Expr::Function { .. } => todo!(),
-        Expr::Shift { .. } => todo!(),
-        Expr::Reverse(_) => todo!(),
-        Expr::Duplicated(_) => todo!(),
-        Expr::IsUnique(_) => todo!(),
-        Expr::Explode(_) => todo!(),
-        Expr::Filter { .. } => todo!(),
-        Expr::Window { .. } => todo!(),
-        Expr::Wildcard => todo!(),
-        Expr::Slice { .. } => todo!(),
-        Expr::Exclude(_, _) => todo!(),
-        Expr::KeepName(_) => todo!(),
-        Expr::RenameAlias { .. } => todo!(),
-        Expr::Count => todo!(),
-        Expr::Nth(_) => todo!(),
-        Expr::AnonymousFunction { .. } => todo!(),
+        Expr::IsNotNull(expr) => {
+            let expr = expr_to_value(expr.as_ref(), span);
+            let cols = vec!["expr".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr],
+                span,
+            }
+        }
+        Expr::IsNull(expr) => {
+            let expr = expr_to_value(expr.as_ref(), span);
+            let cols = vec!["expr".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr],
+                span,
+            }
+        }
+        Expr::Count => {
+            let expr = Value::String {
+                val: "count".into(),
+                span,
+            };
+            let cols = vec!["expr".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr],
+                span,
+            }
+        }
+        Expr::Wildcard => {
+            let expr = Value::String {
+                val: "wildcard".into(),
+                span,
+            };
+            let cols = vec!["expr".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr],
+                span,
+            }
+        }
+        Expr::Reverse(expr) => {
+            let expr = expr_to_value(expr.as_ref(), span);
+            let cols = vec!["expr".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr],
+                span,
+            }
+        }
+        Expr::Duplicated(expr) => {
+            let expr = expr_to_value(expr.as_ref(), span);
+            let cols = vec!["expr".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr],
+                span,
+            }
+        }
+        Expr::IsUnique(expr) => {
+            let expr = expr_to_value(expr.as_ref(), span);
+            let cols = vec!["expr".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr],
+                span,
+            }
+        }
+        Expr::Explode(expr) => {
+            let expr = expr_to_value(expr.as_ref(), span);
+            let cols = vec!["expr".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr],
+                span,
+            }
+        }
+        Expr::KeepName(expr) => {
+            let expr = expr_to_value(expr.as_ref(), span);
+            let cols = vec!["expr".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr],
+                span,
+            }
+        }
+        Expr::Nth(i) => {
+            let expr = Value::int(*i, span);
+            let cols = vec!["expr".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr],
+                span,
+            }
+        }
+        Expr::DtypeColumn(dtypes) => {
+            let vals = dtypes
+                .iter()
+                .map(|d| Value::String {
+                    val: format!("{}", d),
+                    span,
+                })
+                .collect();
+
+            Value::List { vals, span }
+        }
+        Expr::Sort { expr, options } => {
+            let expr = expr_to_value(expr.as_ref(), span);
+            let options = Value::String {
+                val: format!("{:?}", options),
+                span,
+            };
+            let cols = vec!["expr".into(), "options".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr, options],
+                span,
+            }
+        }
+        Expr::Cast {
+            expr,
+            data_type,
+            strict,
+        } => {
+            let expr = expr_to_value(expr.as_ref(), span);
+            let dtype = Value::String {
+                val: format!("{:?}", data_type),
+                span,
+            };
+            let strict = Value::Bool { val: *strict, span };
+
+            let cols = vec!["expr".into(), "dtype".into(), "strict".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr, dtype, strict],
+                span,
+            }
+        }
+        Expr::Take { expr, idx } => {
+            let expr = expr_to_value(expr.as_ref(), span);
+            let idx = expr_to_value(idx.as_ref(), span);
+
+            let cols = vec!["expr".into(), "idx".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr, idx],
+                span,
+            }
+        }
+        Expr::SortBy { expr, by, reverse } => {
+            let expr = expr_to_value(expr.as_ref(), span);
+            let by: Vec<Value> = by.iter().map(|b| expr_to_value(b, span)).collect();
+            let by = Value::List { vals: by, span };
+
+            let reverse: Vec<Value> = reverse
+                .iter()
+                .map(|r| Value::Bool { val: *r, span })
+                .collect();
+            let reverse = Value::List {
+                vals: reverse,
+                span,
+            };
+
+            let cols = vec!["expr".into(), "by".into(), "reverse".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr, by, reverse],
+                span,
+            }
+        }
+        Expr::Shift { input, periods } => {
+            let expr = expr_to_value(input.as_ref(), span);
+            let periods = Value::Int {
+                val: *periods,
+                span,
+            };
+
+            let cols = vec!["expr".into(), "periods".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr, periods],
+                span,
+            }
+        }
+        Expr::Filter { input, by } => {
+            let input = expr_to_value(input.as_ref(), span);
+            let by = expr_to_value(by.as_ref(), span);
+
+            let cols = vec!["input".into(), "by".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![input, by],
+                span,
+            }
+        }
+        Expr::Slice {
+            input,
+            offset,
+            length,
+        } => {
+            let input = expr_to_value(input.as_ref(), span);
+            let offset = expr_to_value(offset.as_ref(), span);
+            let length = expr_to_value(length.as_ref(), span);
+
+            let cols = vec!["input".into(), "offset".into(), "length".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![input, offset, length],
+                span,
+            }
+        }
+        Expr::Exclude(expr, excluded) => {
+            let expr = expr_to_value(expr.as_ref(), span);
+            let excluded = excluded
+                .iter()
+                .map(|e| Value::String {
+                    val: format!("{:?}", e),
+                    span,
+                })
+                .collect();
+            let excluded = Value::List {
+                vals: excluded,
+                span,
+            };
+
+            let cols = vec!["expr".into(), "excluded".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr, excluded],
+                span,
+            }
+        }
+        Expr::RenameAlias { expr, function } => {
+            let expr = expr_to_value(expr.as_ref(), span);
+            let function = Value::String {
+                val: format!("{:?}", function),
+                span,
+            };
+
+            let cols = vec!["expr".into(), "function".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![expr, function],
+                span,
+            }
+        }
+        Expr::AnonymousFunction {
+            input,
+            function,
+            output_type,
+            options,
+        } => {
+            let input: Vec<Value> = input.iter().map(|e| expr_to_value(e, span)).collect();
+            let input = Value::List { vals: input, span };
+
+            let function = Value::String {
+                val: format!("{:?}", function),
+                span,
+            };
+            let output_type = Value::String {
+                val: format!("{:?}", output_type),
+                span,
+            };
+            let options = Value::String {
+                val: format!("{:?}", options),
+                span,
+            };
+
+            let cols = vec![
+                "input".into(),
+                "function".into(),
+                "output_type".into(),
+                "options".into(),
+            ];
+
+            Value::Record {
+                cols,
+                vals: vec![input, function, output_type, options],
+                span,
+            }
+        }
+        Expr::Function {
+            input,
+            function,
+            options,
+        } => {
+            let input: Vec<Value> = input.iter().map(|e| expr_to_value(e, span)).collect();
+            let input = Value::List { vals: input, span };
+
+            let function = Value::String {
+                val: format!("{:?}", function),
+                span,
+            };
+            let options = Value::String {
+                val: format!("{:?}", options),
+                span,
+            };
+
+            let cols = vec!["input".into(), "function".into(), "options".into()];
+
+            Value::Record {
+                cols,
+                vals: vec![input, function, options],
+                span,
+            }
+        }
+        Expr::Window {
+            function,
+            partition_by,
+            order_by,
+            options,
+        } => {
+            let function = expr_to_value(function, span);
+
+            let partition_by: Vec<Value> = partition_by
+                .iter()
+                .map(|e| expr_to_value(e, span))
+                .collect();
+            let partition_by = Value::List {
+                vals: partition_by,
+                span,
+            };
+
+            let order_by = order_by
+                .as_ref()
+                .map(|e| expr_to_value(e.as_ref(), span))
+                .unwrap_or_else(|| Value::nothing(span));
+
+            let options = Value::String {
+                val: format!("{:?}", options),
+                span,
+            };
+
+            let cols = vec![
+                "function".into(),
+                "partition_by".into(),
+                "order_by".into(),
+                "options".into(),
+            ];
+
+            Value::Record {
+                cols,
+                vals: vec![function, partition_by, order_by, options],
+                span,
+            }
+        }
     }
 }

crates/nu-command/src/default_context.rs

@@ -400,9 +400,6 @@ pub fn create_default_context(cwd: impl AsRef<Path>) -> EngineState {
             KeepWhileDeprecated,
         };
 
-        #[cfg(feature = "dataframe")]
-        bind_command!(DataframeDeprecated);
-
         #[cfg(feature = "plugin")]
         bind_command!(Register);
 

crates/nu-command/src/deprecated/dataframe.rs

@@ -1,36 +0,0 @@
-use nu_protocol::{
-    ast::Call,
-    engine::{Command, EngineState, Stack},
-    Category, PipelineData, Signature,
-};
-
-#[derive(Clone)]
-pub struct DataframeDeprecated;
-
-impl Command for DataframeDeprecated {
-    fn name(&self) -> &str {
-        "dataframe"
-    }
-
-    fn signature(&self) -> Signature {
-        Signature::build(self.name()).category(Category::Deprecated)
-    }
-
-    fn usage(&self) -> &str {
-        "Deprecated command"
-    }
-
-    fn run(
-        &self,
-        _engine_state: &EngineState,
-        _stack: &mut Stack,
-        call: &Call,
-        _input: PipelineData,
-    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
-        Err(nu_protocol::ShellError::DeprecatedCommand(
-            self.name().to_string(),
-            "dfr".to_string(),
-            call.head,
-        ))
-    }
-}

crates/nu-command/src/deprecated/mod.rs

@@ -21,9 +21,3 @@ pub use str_decimal::StrDecimalDeprecated;
 pub use str_find_replace::StrFindReplaceDeprecated;
 pub use str_int::StrIntDeprecated;
 pub use unalias::UnaliasDeprecated;
-
-#[cfg(feature = "dataframe")]
-mod dataframe;
-
-#[cfg(feature = "dataframe")]
-pub use dataframe::DataframeDeprecated;

crates/nu-parser/src/parse_keywords.rs

@@ -21,7 +21,7 @@ use crate::{
     parser::{
         check_call, check_name, garbage, garbage_pipeline, parse, parse_block_expression,
         parse_internal_call, parse_multispan_value, parse_signature, parse_string,
-        parse_var_with_opt_type, trim_quotes,
+        parse_var_with_opt_type, trim_quotes, ParsedInternalCall,
     },
     unescape_unquote_string, ParseError,
 };
@@ -127,13 +127,18 @@ pub fn parse_for(
         }
         Some(decl_id) => {
             working_set.enter_scope();
-            let (call, mut err) = parse_internal_call(
+            let ParsedInternalCall {
+                call,
+                error: mut err,
+                output,
+            } = parse_internal_call(
                 working_set,
                 spans[0],
                 &spans[1..],
                 decl_id,
                 expand_aliases_denylist,
             );
+
             working_set.exit_scope();
 
             let call_span = span(spans);
@@ -165,7 +170,7 @@ pub fn parse_for(
                     Expression {
                         expr: Expr::Call(call),
                         span: call_span,
-                        ty: Type::Any,
+                        ty: output,
                         custom_completion: None,
                     },
                     err,
@@ -296,13 +301,18 @@ pub fn parse_def(
         }
         Some(decl_id) => {
             working_set.enter_scope();
-            let (call, mut err) = parse_internal_call(
+            let ParsedInternalCall {
+                call,
+                error: mut err,
+                output,
+            } = parse_internal_call(
                 working_set,
                 spans[0],
                 &spans[1..],
                 decl_id,
                 expand_aliases_denylist,
             );
+
             working_set.exit_scope();
 
             let call_span = span(spans);
@@ -334,7 +344,7 @@ pub fn parse_def(
                     Pipeline::from_vec(vec![Expression {
                         expr: Expr::Call(call),
                         span: call_span,
-                        ty: Type::Any,
+                        ty: output,
                         custom_completion: None,
                     }]),
                     err,
@@ -439,7 +449,9 @@ pub fn parse_extern(
         }
         Some(decl_id) => {
             working_set.enter_scope();
-            let (call, err) = parse_internal_call(
+            let ParsedInternalCall {
+                call, error: err, ..
+            } = parse_internal_call(
                 working_set,
                 spans[0],
                 &spans[1..],
@@ -521,7 +533,7 @@ pub fn parse_alias(
         }
 
         if let Some(decl_id) = working_set.find_decl(b"alias", &Type::Any) {
-            let (call, _) = parse_internal_call(
+            let ParsedInternalCall { call, output, .. } = parse_internal_call(
                 working_set,
                 spans[0],
                 &spans[1..],
@@ -534,7 +546,7 @@ pub fn parse_alias(
                     Pipeline::from_vec(vec![Expression {
                         expr: Expr::Call(call),
                         span: span(spans),
-                        ty: Type::Any,
+                        ty: output,
                         custom_completion: None,
                     }]),
                     None,
@@ -1243,7 +1255,11 @@ pub fn parse_use(
 
     let (call, call_span, use_decl_id) = match working_set.find_decl(b"use", &Type::Any) {
         Some(decl_id) => {
-            let (call, mut err) = parse_internal_call(
+            let ParsedInternalCall {
+                call,
+                error: mut err,
+                output,
+            } = parse_internal_call(
                 working_set,
                 spans[0],
                 &spans[1..],
@@ -1260,7 +1276,7 @@ pub fn parse_use(
                     Pipeline::from_vec(vec![Expression {
                         expr: Expr::Call(call),
                         span: call_span,
-                        ty: Type::Any,
+                        ty: output,
                         custom_completion: None,
                     }]),
                     err,
@@ -1476,7 +1492,11 @@ pub fn parse_hide(
 
     let (call, call_span, hide_decl_id) = match working_set.find_decl(b"hide", &Type::Any) {
         Some(decl_id) => {
-            let (call, mut err) = parse_internal_call(
+            let ParsedInternalCall {
+                call,
+                error: mut err,
+                output,
+            } = parse_internal_call(
                 working_set,
                 spans[0],
                 &spans[1..],
@@ -1493,7 +1513,7 @@ pub fn parse_hide(
                     Pipeline::from_vec(vec![Expression {
                         expr: Expr::Call(call),
                         span: call_span,
-                        ty: Type::Any,
+                        ty: output,
                         custom_completion: None,
                     }]),
                     err,
@@ -1701,7 +1721,11 @@ pub fn parse_overlay(
                 // TODO: Abstract this code blob, it's repeated all over the place:
                 let call = match working_set.find_decl(b"overlay list", &Type::Any) {
                     Some(decl_id) => {
-                        let (call, mut err) = parse_internal_call(
+                        let ParsedInternalCall {
+                            call,
+                            error: mut err,
+                            output,
+                        } = parse_internal_call(
                             working_set,
                             span(&spans[..2]),
                             if spans.len() > 2 { &spans[2..] } else { &[] },
@@ -1718,7 +1742,7 @@ pub fn parse_overlay(
                                 Pipeline::from_vec(vec![Expression {
                                     expr: Expr::Call(call),
                                     span: call_span,
-                                    ty: Type::Any,
+                                    ty: output,
                                     custom_completion: None,
                                 }]),
                                 err,
@@ -1760,7 +1784,11 @@ pub fn parse_overlay(
 
     let call = match working_set.find_decl(b"overlay", &Type::Any) {
         Some(decl_id) => {
-            let (call, mut err) = parse_internal_call(
+            let ParsedInternalCall {
+                call,
+                error: mut err,
+                output,
+            } = parse_internal_call(
                 working_set,
                 spans[0],
                 &spans[1..],
@@ -1777,7 +1805,7 @@ pub fn parse_overlay(
                     Pipeline::from_vec(vec![Expression {
                         expr: Expr::Call(call),
                         span: call_span,
-                        ty: Type::Any,
+                        ty: output,
                         custom_completion: None,
                     }]),
                     err,
@@ -1825,7 +1853,11 @@ pub fn parse_overlay_new(
 
     let (call, call_span) = match working_set.find_decl(b"overlay new", &Type::Any) {
         Some(decl_id) => {
-            let (call, mut err) = parse_internal_call(
+            let ParsedInternalCall {
+                call,
+                error: mut err,
+                output,
+            } = parse_internal_call(
                 working_set,
                 span(&spans[0..2]),
                 &spans[2..],
@@ -1842,7 +1874,7 @@ pub fn parse_overlay_new(
                     Pipeline::from_vec(vec![Expression {
                         expr: Expr::Call(call),
                         span: call_span,
-                        ty: Type::Any,
+                        ty: output,
                         custom_completion: None,
                     }]),
                     err,
@@ -1916,7 +1948,11 @@ pub fn parse_overlay_add(
     // TODO: Allow full import pattern as argument (requires custom naming of module/overlay)
     let (call, call_span) = match working_set.find_decl(b"overlay add", &Type::Any) {
         Some(decl_id) => {
-            let (call, mut err) = parse_internal_call(
+            let ParsedInternalCall {
+                call,
+                error: mut err,
+                output,
+            } = parse_internal_call(
                 working_set,
                 span(&spans[0..2]),
                 &spans[2..],
@@ -1933,7 +1969,7 @@ pub fn parse_overlay_add(
                     Pipeline::from_vec(vec![Expression {
                         expr: Expr::Call(call),
                         span: call_span,
-                        ty: Type::Any,
+                        ty: output,
                         custom_completion: None,
                     }]),
                     err,
@@ -2103,7 +2139,11 @@ pub fn parse_overlay_remove(
 
     let call = match working_set.find_decl(b"overlay remove", &Type::Any) {
         Some(decl_id) => {
-            let (call, mut err) = parse_internal_call(
+            let ParsedInternalCall {
+                call,
+                error: mut err,
+                output,
+            } = parse_internal_call(
                 working_set,
                 span(&spans[0..2]),
                 &spans[2..],
@@ -2120,7 +2160,7 @@ pub fn parse_overlay_remove(
                     Pipeline::from_vec(vec![Expression {
                         expr: Expr::Call(call),
                         span: call_span,
-                        ty: Type::Any,
+                        ty: output,
                         custom_completion: None,
                     }]),
                     err,
@@ -2247,7 +2287,6 @@ pub fn parse_let(
                         error = error.or(err);
 
                         let var_id = lvalue.as_var();
-
                         let rhs_type = rvalue.ty.clone();
 
                         if let Some(var_id) = var_id {
@@ -2277,7 +2316,11 @@ pub fn parse_let(
                     }
                 }
             }
-            let (call, err) = parse_internal_call(
+            let ParsedInternalCall {
+                call,
+                error: err,
+                output,
+            } = parse_internal_call(
                 working_set,
                 spans[0],
                 &spans[1..],
@@ -2290,7 +2333,7 @@ pub fn parse_let(
                     expressions: vec![Expression {
                         expr: Expr::Call(call),
                         span: nu_protocol::span(spans),
-                        ty: Type::Any,
+                        ty: output,
                         custom_completion: None,
                     }],
                 },
@@ -2320,7 +2363,11 @@ pub fn parse_source(
             let cwd = working_set.get_cwd();
             // Is this the right call to be using here?
             // Some of the others (`parse_let`) use it, some of them (`parse_hide`) don't.
-            let (call, err) = parse_internal_call(
+            let ParsedInternalCall {
+                call,
+                error: err,
+                output,
+            } = parse_internal_call(
                 working_set,
                 spans[0],
                 &spans[1..],
@@ -2334,7 +2381,7 @@ pub fn parse_source(
                     Pipeline::from_vec(vec![Expression {
                         expr: Expr::Call(call),
                         span: span(spans),
-                        ty: Type::Any,
+                        ty: output,
                         custom_completion: None,
                     }]),
                     error,
@@ -2459,7 +2506,11 @@ pub fn parse_register(
             )
         }
         Some(decl_id) => {
-            let (call, mut err) = parse_internal_call(
+            let ParsedInternalCall {
+                call,
+                error: mut err,
+                output,
+            } = parse_internal_call(
                 working_set,
                 spans[0],
                 &spans[1..],
@@ -2476,7 +2527,7 @@ pub fn parse_register(
                     Pipeline::from_vec(vec![Expression {
                         expr: Expr::Call(call),
                         span: call_span,
-                        ty: Type::Any,
+                        ty: output,
                         custom_completion: None,
                     }]),
                     err,

crates/nu-parser/src/parser.rs

@@ -724,13 +724,19 @@ pub fn parse_multispan_value(
     }
 }
 
+pub struct ParsedInternalCall {
+    pub call: Box<Call>,
+    pub output: Type,
+    pub error: Option<ParseError>,
+}
+
 pub fn parse_internal_call(
     working_set: &mut StateWorkingSet,
     command_span: Span,
     spans: &[Span],
     decl_id: usize,
     expand_aliases_denylist: &[usize],
-) -> (Box<Call>, Option<ParseError>) {
+) -> ParsedInternalCall {
     trace!("parsing: internal call (decl id: {})", decl_id);
 
     let mut error = None;
@@ -742,7 +748,8 @@ pub fn parse_internal_call(
     let decl = working_set.get_decl(decl_id);
     let signature = decl.signature();
     let output = decl.output_type();
-    working_set.found_outputs.push(output);
+
+    working_set.type_scope.add_type(output.clone());
 
     if signature.creates_scope {
         working_set.enter_scope();
@@ -925,8 +932,11 @@ pub fn parse_internal_call(
         working_set.exit_scope();
     }
 
-    // FIXME: output type unknown
-    (Box::new(call), error)
+    ParsedInternalCall {
+        call: Box::new(call),
+        output,
+        error,
+    }
 }
 
 pub fn parse_call(
@@ -1012,7 +1022,7 @@ pub fn parse_call(
         pos += 1;
     }
 
-    let input = working_set.found_outputs.last().unwrap_or(&Type::Any);
+    let input = working_set.type_scope.get_previous();
     let mut maybe_decl_id = working_set.find_decl(&name, input);
 
     while maybe_decl_id.is_none() {
@@ -1060,21 +1070,22 @@ pub fn parse_call(
         trace!("parsing: internal call");
 
         // parse internal command
-        let (call, err) = parse_internal_call(
+        let parsed_call = parse_internal_call(
             working_set,
             span(&spans[cmd_start..pos]),
             &spans[pos..],
             decl_id,
             expand_aliases_denylist,
         );
+
         (
             Expression {
-                expr: Expr::Call(call),
+                expr: Expr::Call(parsed_call.call),
                 span: span(spans),
-                ty: Type::Any, // FIXME: calls should have known output types
+                ty: parsed_call.output,
                 custom_completion: None,
             },
-            err,
+            parsed_call.error,
         )
     } else {
         // We might be parsing left-unbounded range ("..10")
@@ -1853,8 +1864,14 @@ pub fn parse_full_cell_path(
             let (output, err) = lite_parse(&output);
             error = error.or(err);
 
+            // Creating a Type scope to parse the new block. This will keep track of
+            // the previous input type found in that block
             let (output, err) =
                 parse_block(working_set, &output, true, expand_aliases_denylist, true);
+            working_set
+                .type_scope
+                .add_type(working_set.type_scope.get_last_output());
+
             error = error.or(err);
 
             let block_id = working_set.add_block(output);
@@ -1864,7 +1881,7 @@ pub fn parse_full_cell_path(
                 Expression {
                     expr: Expr::Subexpression(block_id),
                     span: head_span,
-                    ty: Type::Any, // FIXME
+                    ty: working_set.type_scope.get_last_output(),
                     custom_completion: None,
                 },
                 true,
@@ -1929,8 +1946,8 @@ pub fn parse_full_cell_path(
         if !tail.is_empty() {
             (
                 Expression {
+                    ty: head.ty.clone(), // FIXME. How to access the last type of tail?
                     expr: Expr::FullCellPath(Box::new(FullCellPath { head, tail })),
-                    ty: Type::Any,
                     span: full_cell_span,
                     custom_completion: None,
                 },
@@ -4581,6 +4598,9 @@ pub fn parse_variable(
 
     if is_variable(bytes) {
         if let Some(var_id) = working_set.find_variable(bytes) {
+            let input = working_set.get_variable(var_id).ty.clone();
+            working_set.type_scope.add_type(input);
+
             (Some(var_id), None)
         } else {
             (None, None)
@@ -4612,19 +4632,20 @@ pub fn parse_builtin_commands(
         b"source" => parse_source(working_set, &lite_command.parts, expand_aliases_denylist),
         b"export" => {
             if let Some(decl_id) = working_set.find_decl(b"alias", &Type::Any) {
-                let (call, _) = parse_internal_call(
+                let parsed_call = parse_internal_call(
                     working_set,
                     lite_command.parts[0],
                     &lite_command.parts[1..],
                     decl_id,
                     expand_aliases_denylist,
                 );
-                if call.has_flag("help") {
+
+                if parsed_call.call.has_flag("help") {
                     (
                         Pipeline::from_vec(vec![Expression {
-                            expr: Expr::Call(call),
+                            expr: Expr::Call(parsed_call.call),
                             span: span(&lite_command.parts),
-                            ty: Type::Any,
+                            ty: parsed_call.output,
                             custom_completion: None,
                         }]),
                         None,
@@ -4759,6 +4780,7 @@ pub fn parse_block(
     if scoped {
         working_set.enter_scope();
     }
+    working_set.type_scope.enter_scope();
 
     let mut error = None;
 
@@ -4789,6 +4811,8 @@ pub fn parse_block(
                         let (expr, err) =
                             parse_expression(working_set, &command.parts, expand_aliases_denylist);
 
+                        working_set.type_scope.add_type(expr.ty.clone());
+
                         if error.is_none() {
                             error = err;
                         }
@@ -4872,6 +4896,7 @@ pub fn parse_block(
     if scoped {
         working_set.exit_scope();
     }
+    working_set.type_scope.exit_scope();
 
     (block, error)
 }