ListStream touchup (#12524)

# Description

Does some misc changes to `ListStream`:
- Moves it into its own module/file separate from `RawStream`.
- `ListStream`s now have an associated `Span`.
- This required changes to `ListStreamInfo` in `nu-plugin`. Note sure if
this is a breaking change for the plugin protocol.
- Hides the internals of `ListStream` but also adds a few more methods.
- This includes two functions to more easily alter a stream (these take
a `ListStream` and return a `ListStream` instead of having to go through
the whole `into_pipeline_data(..)` route).
  -  `map`: takes a `FnMut(Value) -> Value`
  - `modify`: takes a function to modify the inner stream.

crates/nu-command/src/system/complete.rs

@@ -88,7 +88,7 @@ impl Command for Complete {
                 };
 
                 if let Some(exit_code) = exit_code {
-                    let mut v: Vec<_> = exit_code.collect();
+                    let mut v: Vec<_> = exit_code.into_iter().collect();
 
                     if let Some(v) = v.pop() {
                         record.push("exit_code", v);

crates/nu-command/src/system/ps.rs

@@ -195,5 +195,5 @@ fn run_ps(
 
     Ok(output
         .into_iter()
-        .into_pipeline_data(engine_state.ctrlc.clone()))
+        .into_pipeline_data(span, engine_state.ctrlc.clone()))
 }

crates/nu-command/src/system/registry_query.rs

@@ -106,7 +106,7 @@ fn registry_query(
                 *registry_key_span,
             ))
         }
-        Ok(reg_values.into_pipeline_data(engine_state.ctrlc.clone()))
+        Ok(reg_values.into_pipeline_data(call_span, engine_state.ctrlc.clone()))
     } else {
         match registry_value {
             Some(value) => {

crates/nu-command/src/system/run_external.rs

@@ -163,8 +163,6 @@ impl ExternalCommand {
     ) -> Result<PipelineData, ShellError> {
         let head = self.name.span;
 
-        let ctrlc = engine_state.ctrlc.clone();
-
         #[allow(unused_mut)]
         let (cmd, mut reader) = self.create_process(&input, false, head)?;
 
@@ -431,7 +429,7 @@ impl ExternalCommand {
                     (
                         Some(RawStream::new(
                             Box::new(ByteLines::new(combined)),
-                            ctrlc.clone(),
+                            engine_state.ctrlc.clone(),
                             head,
                             None,
                         )),
@@ -439,11 +437,21 @@ impl ExternalCommand {
                     )
                 } else {
                     let stdout = child.as_mut().stdout.take().map(|out| {
-                        RawStream::new(Box::new(ByteLines::new(out)), ctrlc.clone(), head, None)
+                        RawStream::new(
+                            Box::new(ByteLines::new(out)),
+                            engine_state.ctrlc.clone(),
+                            head,
+                            None,
+                        )
                     });
 
                     let stderr = child.as_mut().stderr.take().map(|err| {
-                        RawStream::new(Box::new(ByteLines::new(err)), ctrlc.clone(), head, None)
+                        RawStream::new(
+                            Box::new(ByteLines::new(err)),
+                            engine_state.ctrlc.clone(),
+                            head,
+                            None,
+                        )
                     });
 
                     if matches!(self.err, OutDest::Pipe) {
@@ -505,15 +513,16 @@ impl ExternalCommand {
                     })
                     .err_span(head)?;
 
-                let exit_code_receiver = ValueReceiver::new(exit_code_rx);
+                let exit_code = Some(ListStream::new(
+                    ValueReceiver::new(exit_code_rx),
+                    head,
+                    None,
+                ));
 
                 Ok(PipelineData::ExternalStream {
                     stdout,
                     stderr,
-                    exit_code: Some(ListStream::from_stream(
-                        Box::new(exit_code_receiver),
-                        ctrlc.clone(),
-                    )),
+                    exit_code,
                     span: head,
                     metadata: None,
                     trim_end_newline: true,

crates/nu-command/src/system/which_.rs

@@ -214,6 +214,7 @@ fn which(
     stack: &mut Stack,
     call: &Call,
 ) -> Result<PipelineData, ShellError> {
+    let head = call.head;
     let which_args = WhichArgs {
         applications: call.rest(engine_state, stack, 0)?,
         all: call.has_flag(engine_state, stack, "all")?,
@@ -223,7 +224,7 @@ fn which(
     if which_args.applications.is_empty() {
         return Err(ShellError::MissingParameter {
             param_name: "application".into(),
-            span: call.head,
+            span: head,
         });
     }
 
@@ -231,7 +232,7 @@ fn which(
 
     #[allow(deprecated)]
     let cwd = env::current_dir_str(engine_state, stack)?;
-    let paths = env::path_str(engine_state, stack, call.head)?;
+    let paths = env::path_str(engine_state, stack, head)?;
 
     for app in which_args.applications {
         let values = which_single(
@@ -244,7 +245,7 @@ fn which(
         output.extend(values);
     }
 
-    Ok(output.into_iter().into_pipeline_data(ctrlc))
+    Ok(output.into_iter().into_pipeline_data(head, ctrlc))
 }
 
 #[cfg(test)]