Reuse Closure type in Value::Closure (#10894)

# Description
Reuses the existing `Closure` type in `Value::Closure`. This will help
with the span refactoring for `Value`. Additionally, this allows us to
more easily box or unbox the `Closure` case should we chose to do so in
the future.

# User-Facing Changes
Breaking API change for `nu_protocol`.

crates/nu-command/src/charting/hashable_value.rs

@@ -178,7 +178,10 @@ impl PartialEq for HashableValue {
 #[cfg(test)]
 mod test {
     use super::*;
-    use nu_protocol::ast::{CellPath, PathMember};
+    use nu_protocol::{
+        ast::{CellPath, PathMember},
+        engine::Closure,
+    };
     use std::collections::{HashMap, HashSet};
 
     #[test]
@@ -237,7 +240,13 @@ mod test {
         let span = Span::test_data();
         let values = [
             Value::list(vec![Value::bool(true, span)], span),
-            Value::closure(0, HashMap::new(), span),
+            Value::closure(
+                Closure {
+                    block_id: 0,
+                    captures: HashMap::new(),
+                },
+                span,
+            ),
             Value::nothing(span),
             Value::error(ShellError::DidYouMean("what?".to_string(), span), span),
             Value::cell_path(

crates/nu-command/src/database/commands/into_sqlite.rs

@@ -259,7 +259,7 @@ fn nu_value_to_string(value: Value, separator: &str) -> String {
             Err(error) => format!("{error:?}"),
         },
         Value::Block { val, .. } => format!("<Block {val}>"),
-        Value::Closure { val, .. } => format!("<Closure {val}>"),
+        Value::Closure { val, .. } => format!("<Closure {}>", val.block_id),
         Value::Nothing { .. } => String::new(),
         Value::Error { error, .. } => format!("{error:?}"),
         Value::Binary { val, .. } => format!("{val:?}"),

crates/nu-command/src/debug/explain.rs

@@ -253,7 +253,7 @@ pub fn debug_string_without_formatting(value: &Value) -> String {
         },
         //TODO: It would be good to drill in deeper to blocks and closures.
         Value::Block { val, .. } => format!("<Block {val}>"),
-        Value::Closure { val, .. } => format!("<Closure {val}>"),
+        Value::Closure { val, .. } => format!("<Closure {}>", val.block_id),
         Value::Nothing { .. } => String::new(),
         Value::Error { error, .. } => format!("{error:?}"),
         Value::Binary { val, .. } => format!("{val:?}"),

crates/nu-command/src/debug/view_source.rs

@@ -37,17 +37,6 @@ impl Command for ViewSource {
         let arg_span = arg.span();
 
         match arg {
-            Value::Block { val: block_id, .. } | Value::Closure { val: block_id, .. } => {
-                let block = engine_state.get_block(block_id);
-
-                if let Some(span) = block.span {
-                    let contents = engine_state.get_span_contents(span);
-                    Ok(Value::string(String::from_utf8_lossy(contents), call.head)
-                        .into_pipeline_data())
-                } else {
-                    Ok(Value::string("<internal command>", call.head).into_pipeline_data())
-                }
-            }
             Value::String { val, .. } => {
                 if let Some(decl_id) = engine_state.find_decl(val.as_bytes(), &[]) {
                     // arg is a command
@@ -139,13 +128,27 @@ impl Command for ViewSource {
                     ))
                 }
             }
-            _ => Err(ShellError::GenericError(
-                "Cannot view value".to_string(),
-                "this value cannot be viewed".to_string(),
-                Some(arg_span),
-                None,
-                Vec::new(),
-            )),
+            value => {
+                if let Ok(block_id) = value.as_block() {
+                    let block = engine_state.get_block(block_id);
+
+                    if let Some(span) = block.span {
+                        let contents = engine_state.get_span_contents(span);
+                        Ok(Value::string(String::from_utf8_lossy(contents), call.head)
+                            .into_pipeline_data())
+                    } else {
+                        Ok(Value::string("<internal command>", call.head).into_pipeline_data())
+                    }
+                } else {
+                    Err(ShellError::GenericError(
+                        "Cannot view value".to_string(),
+                        "this value cannot be viewed".to_string(),
+                        Some(arg_span),
+                        None,
+                        Vec::new(),
+                    ))
+                }
+            }
         }
     }
 

crates/nu-command/src/formats/to/text.rs

@@ -142,7 +142,7 @@ fn local_into_string(value: Value, separator: &str, config: &Config) -> String {
             Err(error) => format!("{error:?}"),
         },
         Value::Block { val, .. } => format!("<Block {val}>"),
-        Value::Closure { val, .. } => format!("<Closure {val}>"),
+        Value::Closure { val, .. } => format!("<Closure {}>", val.block_id),
         Value::Nothing { .. } => String::new(),
         Value::Error { error, .. } => format!("{error:?}"),
         Value::Binary { val, .. } => format!("{val:?}"),