Add "move column" command. (#2123)

crates/nu-cli/src/commands/move_/column.rs

@@ -0,0 +1,335 @@
+use crate::commands::WholeStreamCommand;
+use crate::context::CommandRegistry;
+use crate::data::base::select_fields;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ColumnPath, ReturnSuccess, Signature, SyntaxShape, Value};
+use nu_source::span_for_spanned_list;
+
+pub struct SubCommand;
+
+#[derive(Deserialize)]
+pub struct Arguments {
+    rest: Vec<ColumnPath>,
+    after: Option<ColumnPath>,
+    before: Option<ColumnPath>,
+}
+
+#[async_trait]
+impl WholeStreamCommand for SubCommand {
+    fn name(&self) -> &str {
+        "move column"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("move column")
+            .rest(SyntaxShape::ColumnPath, "the columns to move")
+            .named(
+                "after",
+                SyntaxShape::ColumnPath,
+                "the column that will precede the columns moved",
+                None,
+            )
+            .named(
+                "before",
+                SyntaxShape::ColumnPath,
+                "the column that will be next the columns moved",
+                None,
+            )
+    }
+
+    fn usage(&self) -> &str {
+        "Move columns."
+    }
+
+    async fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        operate(args, registry).await
+    }
+}
+
+async fn operate(
+    raw_args: CommandArgs,
+    registry: &CommandRegistry,
+) -> Result<OutputStream, ShellError> {
+    let name = raw_args.call_info.name_tag.clone();
+    let registry = registry.clone();
+    let (
+        Arguments {
+            rest: mut columns,
+            before,
+            after,
+        },
+        input,
+    ) = raw_args.process(&registry).await?;
+
+    if columns.is_empty() {
+        return Err(ShellError::labeled_error(
+            "expected columns",
+            "expected columns",
+            name,
+        ));
+    }
+
+    if columns.iter().any(|c| c.members().len() > 1) {
+        return Err(ShellError::labeled_error(
+            "expected columns",
+            "expected columns",
+            name,
+        ));
+    }
+
+    if vec![&after, &before]
+        .iter()
+        .map(|o| if o.is_some() { 1 } else { 0 })
+        .sum::<usize>()
+        > 1
+    {
+        return Err(ShellError::labeled_error(
+            "can't move column(s)",
+            "pick exactly one (before, after)",
+            name,
+        ));
+    }
+
+    if let Some(after) = after {
+        let member = columns.remove(0);
+
+        Ok(input
+            .map(move |item| {
+                let member = vec![member.clone()];
+                let column_paths = vec![&member, &columns]
+                    .into_iter()
+                    .flatten()
+                    .collect::<Vec<&ColumnPath>>();
+
+                let after_span = span_for_spanned_list(after.members().iter().map(|p| p.span));
+
+                if after.members().len() == 1 {
+                    let keys = column_paths
+                        .iter()
+                        .filter_map(|c| c.last())
+                        .map(|c| c.as_string())
+                        .collect::<Vec<_>>();
+
+                    if let Some(column) = after.last() {
+                        if !keys.contains(&column.as_string()) {
+                            ReturnSuccess::value(move_after(&item, &keys, &after, &name)?)
+                        } else {
+                            let msg =
+                                format!("can't move column {} after itself", column.as_string());
+                            Err(ShellError::labeled_error(
+                                "can't move column",
+                                msg,
+                                after_span,
+                            ))
+                        }
+                    } else {
+                        Err(ShellError::labeled_error(
+                            "expected column",
+                            "expected column",
+                            after_span,
+                        ))
+                    }
+                } else {
+                    Err(ShellError::labeled_error(
+                        "expected column",
+                        "expected column",
+                        after_span,
+                    ))
+                }
+            })
+            .to_output_stream())
+    } else if let Some(before) = before {
+        let member = columns.remove(0);
+
+        Ok(input
+            .map(move |item| {
+                let member = vec![member.clone()];
+                let column_paths = vec![&member, &columns]
+                    .into_iter()
+                    .flatten()
+                    .collect::<Vec<&ColumnPath>>();
+
+                let before_span = span_for_spanned_list(before.members().iter().map(|p| p.span));
+
+                if before.members().len() == 1 {
+                    let keys = column_paths
+                        .iter()
+                        .filter_map(|c| c.last())
+                        .map(|c| c.as_string())
+                        .collect::<Vec<_>>();
+
+                    if let Some(column) = before.last() {
+                        if !keys.contains(&column.as_string()) {
+                            ReturnSuccess::value(move_before(&item, &keys, &before, &name)?)
+                        } else {
+                            let msg =
+                                format!("can't move column {} before itself", column.as_string());
+                            Err(ShellError::labeled_error(
+                                "can't move column",
+                                msg,
+                                before_span,
+                            ))
+                        }
+                    } else {
+                        Err(ShellError::labeled_error(
+                            "expected column",
+                            "expected column",
+                            before_span,
+                        ))
+                    }
+                } else {
+                    Err(ShellError::labeled_error(
+                        "expected column",
+                        "expected column",
+                        before_span,
+                    ))
+                }
+            })
+            .to_output_stream())
+    } else {
+        Err(ShellError::labeled_error(
+            "no columns given",
+            "no columns given",
+            name,
+        ))
+    }
+}
+
+fn move_after(
+    table: &Value,
+    columns: &[String],
+    from: &ColumnPath,
+    tag: impl Into<Tag>,
+) -> Result<Value, ShellError> {
+    let tag = tag.into();
+    let from_fields = span_for_spanned_list(from.members().iter().map(|p| p.span));
+    let from = if let Some((last, _)) = from.split_last() {
+        last.as_string()
+    } else {
+        return Err(ShellError::labeled_error(
+            "unknown column",
+            "unknown column",
+            from_fields,
+        ));
+    };
+
+    let columns_moved = table
+        .data_descriptors()
+        .into_iter()
+        .map(|name| {
+            if columns.contains(&name) {
+                None
+            } else {
+                Some(name)
+            }
+        })
+        .collect::<Vec<_>>();
+
+    let mut reordered_columns = vec![];
+    let mut insert = false;
+    let mut inserted = false;
+
+    for name in columns_moved.into_iter() {
+        if let Some(name) = name {
+            reordered_columns.push(Some(name.clone()));
+
+            if !inserted && name == from {
+                insert = true;
+            }
+        } else {
+            reordered_columns.push(None);
+        }
+
+        if insert {
+            for column in columns {
+                reordered_columns.push(Some(column.clone()));
+            }
+            inserted = true;
+        }
+    }
+
+    Ok(select_fields(
+        table,
+        &reordered_columns
+            .into_iter()
+            .filter_map(|v| v)
+            .collect::<Vec<_>>(),
+        &tag,
+    ))
+}
+
+fn move_before(
+    table: &Value,
+    columns: &[String],
+    from: &ColumnPath,
+    tag: impl Into<Tag>,
+) -> Result<Value, ShellError> {
+    let tag = tag.into();
+    let from_fields = span_for_spanned_list(from.members().iter().map(|p| p.span));
+    let from = if let Some((last, _)) = from.split_last() {
+        last.as_string()
+    } else {
+        return Err(ShellError::labeled_error(
+            "unknown column",
+            "unknown column",
+            from_fields,
+        ));
+    };
+
+    let columns_moved = table
+        .data_descriptors()
+        .into_iter()
+        .map(|name| {
+            if columns.contains(&name) {
+                None
+            } else {
+                Some(name)
+            }
+        })
+        .collect::<Vec<_>>();
+
+    let mut reordered_columns = vec![];
+    let mut inserted = false;
+
+    for name in columns_moved.into_iter() {
+        if let Some(name) = name {
+            if !inserted && name == from {
+                for column in columns {
+                    reordered_columns.push(Some(column.clone()));
+                }
+
+                inserted = true;
+            }
+
+            reordered_columns.push(Some(name.clone()));
+        } else {
+            reordered_columns.push(None);
+        }
+    }
+
+    Ok(select_fields(
+        table,
+        &reordered_columns
+            .into_iter()
+            .filter_map(|v| v)
+            .collect::<Vec<_>>(),
+        &tag,
+    ))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::SubCommand;
+
+    #[test]
+    fn examples_work_as_expected() {
+        use crate::examples::test as test_examples;
+
+        test_examples(SubCommand {})
+    }
+}

crates/nu-cli/src/commands/move_/command.rs

@@ -0,0 +1,46 @@
+use crate::commands::WholeStreamCommand;
+use crate::prelude::*;
+use nu_errors::ShellError;
+use nu_protocol::{ReturnSuccess, Signature, UntaggedValue};
+
+#[derive(Clone)]
+pub struct Command;
+
+#[async_trait]
+impl WholeStreamCommand for Command {
+    fn name(&self) -> &str {
+        "move"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("move")
+    }
+
+    fn usage(&self) -> &str {
+        "moves across desired subcommand."
+    }
+
+    async fn run(
+        &self,
+        _args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        let registry = registry.clone();
+        Ok(OutputStream::one(Ok(ReturnSuccess::Value(
+            UntaggedValue::string(crate::commands::help::get_help(&Command, &registry))
+                .into_value(Tag::unknown()),
+        ))))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Command;
+
+    #[test]
+    fn examples_work_as_expected() {
+        use crate::examples::test as test_examples;
+
+        test_examples(Command {})
+    }
+}

crates/nu-cli/src/commands/move_/mod.rs

@@ -0,0 +1,7 @@
+mod column;
+mod command;
+pub mod mv;
+
+pub use column::SubCommand as MoveColumn;
+pub use command::Command as Move;
+pub use mv::Mv;

crates/nu-cli/src/commands/move_/mv.rs

@@ -6,16 +6,16 @@ use nu_protocol::{Signature, SyntaxShape};
 use nu_source::Tagged;
 use std::path::PathBuf;
 
-pub struct Move;
+pub struct Mv;
 
 #[derive(Deserialize)]
-pub struct MoveArgs {
+pub struct Arguments {
     pub src: Tagged<PathBuf>,
     pub dst: Tagged<PathBuf>,
 }
 
 #[async_trait]
-impl WholeStreamCommand for Move {
+impl WholeStreamCommand for Mv {
     fn name(&self) -> &str {
         "mv"
     }
@@ -78,12 +78,12 @@ async fn mv(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStrea
 
 #[cfg(test)]
 mod tests {
-    use super::Move;
+    use super::Mv;
 
     #[test]
     fn examples_work_as_expected() {
         use crate::examples::test as test_examples;
 
-        test_examples(Move {})
+        test_examples(Mv {})
     }
 }