histogram: optionally use a valuator for histogram value.

crates/nu-cli/src/commands/histogram.rs

@@ -1,16 +1,13 @@
 use crate::commands::WholeStreamCommand;
 use crate::prelude::*;
 use nu_errors::ShellError;
-use nu_protocol::{ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder, UntaggedValue, Value};
+use nu_protocol::{
+    ColumnPath, ReturnSuccess, Signature, SyntaxShape, TaggedDictBuilder, UntaggedValue, Value,
+};
 use nu_source::Tagged;
 
 pub struct Histogram;
 
-#[derive(Deserialize)]
-pub struct HistogramArgs {
-    rest: Vec<Tagged<String>>,
-}
-
 #[async_trait]
 impl WholeStreamCommand for Histogram {
     fn name(&self) -> &str {
@@ -18,10 +15,17 @@ impl WholeStreamCommand for Histogram {
     }
 
     fn signature(&self) -> Signature {
-        Signature::build("histogram").rest(
+        Signature::build("histogram")
-            SyntaxShape::String,
+            .named(
-            "column name to give the histogram's frequency column",
+                "use",
-        )
+                SyntaxShape::ColumnPath,
+                "Use data at the column path given as valuator",
+                None,
+            )
+            .rest(
+                SyntaxShape::ColumnPath,
+                "column name to give the histogram's frequency column",
+            )
     }
 
     fn usage(&self) -> &str {
@@ -64,22 +68,37 @@ pub async fn histogram(
 ) -> Result<OutputStream, ShellError> {
     let registry = registry.clone();
     let name = args.call_info.name_tag.clone();
+    let (input, args) = args.evaluate_once(&registry).await?.parts();
 
-    let (HistogramArgs { rest: mut columns }, input) = args.process(&registry).await?;
     let values: Vec<Value> = input.collect().await;
 
-    let column_grouper = if !columns.is_empty() {
+    let mut columns = args
-        Some(columns.remove(0))
+        .positional_iter()
+        .map(|c| c.as_column_path())
+        .filter_map(Result::ok)
+        .collect::<Vec<_>>();
+
+    let evaluate_with = if let Some(path) = args.get("use") {
+        Some(evaluator(path.as_column_path()?.item))
     } else {
         None
     };
 
-    let column_names_supplied: Vec<_> = columns.iter().map(|f| f.item.clone()).collect();
+    let column_grouper = if !columns.is_empty() {
-
+        match columns.remove(0).split_last() {
-    let frequency_column_name = if column_names_supplied.is_empty() {
+            Some((key, _)) => Some(key.as_string().tagged(&name)),
-        "frequency".to_string()
+            None => None,
+        }
     } else {
-        column_names_supplied[0].clone()
+        None
+    };
+
+    let frequency_column_name = if columns.is_empty() {
+        "frequency".to_string()
+    } else if let Some((key, _)) = columns[0].split_last() {
+            key.as_string()
+    } else {
+            "frecuency".to_string()
     };
 
     let column = if let Some(ref column) = column_grouper {
@@ -94,7 +113,7 @@ pub async fn histogram(
             grouper: Some(Box::new(move |_, _| Ok(String::from("frequencies")))),
             splitter: Some(splitter(column_grouper)),
             format: None,
-            eval: &None,
+            eval: &evaluate_with,
         },
         &name,
     )?;
@@ -155,6 +174,23 @@ pub async fn histogram(
     .to_output_stream())
 }
 
+fn evaluator(by: ColumnPath) -> Box<dyn Fn(usize, &Value) -> Result<Value, ShellError> + Send> {
+    Box::new(move |_: usize, value: &Value| {
+        let path = by.clone();
+
+        let eval = nu_value_ext::get_data_by_column_path(
+            value,
+            &path,
+            Box::new(move |(_, _, error)| error),
+        );
+
+        match eval {
+            Ok(with_value) => Ok(with_value),
+            Err(reason) => Err(reason),
+        }
+    })
+}
+
 fn splitter(
     by: Option<Tagged<String>>,
 ) -> Box<dyn Fn(usize, &Value) -> Result<String, ShellError> + Send> {

crates/nu-cli/src/data/value.rs

@@ -62,6 +62,43 @@ fn zero_division_error() -> UntaggedValue {
     UntaggedValue::Error(ShellError::untagged_runtime_error("division by zero"))
 }
 
+pub fn unsafe_compute_values(
+    operator: Operator,
+    left: &UntaggedValue,
+    right: &UntaggedValue,
+) -> Result<UntaggedValue, (&'static str, &'static str)> {
+    let computed = compute_values(operator, left, right);
+
+    if computed.is_ok() {
+        return computed;
+    }
+
+    match (left, right) {
+        (UntaggedValue::Primitive(lhs), UntaggedValue::Primitive(rhs)) => match (lhs, rhs) {
+            (Primitive::Filesize(x), Primitive::Int(y)) => match operator {
+                Operator::Plus => Ok(UntaggedValue::Primitive(Primitive::Int(x + y))),
+                Operator::Minus => Ok(UntaggedValue::Primitive(Primitive::Int(x - y))),
+                Operator::Multiply => Ok(UntaggedValue::Primitive(Primitive::Int(x * y))),
+                Operator::Divide => Ok(UntaggedValue::Primitive(Primitive::Decimal(
+                    bigdecimal::BigDecimal::from(*x) / bigdecimal::BigDecimal::from(y.clone()),
+                ))),
+                _ => Err((left.type_name(), right.type_name())),
+            },
+            (Primitive::Int(x), Primitive::Filesize(y)) => match operator {
+                Operator::Plus => Ok(UntaggedValue::Primitive(Primitive::Int(x + y))),
+                Operator::Minus => Ok(UntaggedValue::Primitive(Primitive::Int(x - y))),
+                Operator::Multiply => Ok(UntaggedValue::Primitive(Primitive::Int(x * y))),
+                Operator::Divide => Ok(UntaggedValue::Primitive(Primitive::Decimal(
+                    bigdecimal::BigDecimal::from(x.clone()) / bigdecimal::BigDecimal::from(*y),
+                ))),
+                _ => Err((left.type_name(), right.type_name())),
+            },
+            _ => Err((left.type_name(), right.type_name())),
+        },
+        _ => Err((left.type_name(), right.type_name())),
+    }
+}
+
 pub fn compute_values(
     operator: Operator,
     left: &UntaggedValue,