Merge pull request #112 from nushell/fix_for

Fix the for loop to create vars

crates/nu-command/src/core_commands/for_.rs

@@ -18,7 +18,7 @@ impl Command for For {
         Signature::build("for")
             .required(
                 "var_name",
-                SyntaxShape::Variable,
+                SyntaxShape::VarWithOptType,
                 "name of the looping variable",
             )
             .required(
@@ -34,6 +34,7 @@ impl Command for For {
                 SyntaxShape::Block(Some(vec![])),
                 "the block to run",
             )
+            .creates_scope()
     }
 
     fn run(

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

@@ -2,6 +2,7 @@ mod alias;
 mod def;
 mod do_;
 mod export_def;
+mod for_;
 mod help;
 mod hide;
 mod if_;
@@ -14,6 +15,7 @@ pub use alias::Alias;
 pub use def::Def;
 pub use do_::Do;
 pub use export_def::ExportDef;
+pub use for_::For;
 pub use help::Help;
 pub use hide::Hide;
 pub use if_::If;

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

@@ -1,5 +1,4 @@
 mod each;
-mod for_;
 mod get;
 mod length;
 mod lines;
@@ -8,7 +7,6 @@ mod where_;
 mod wrap;
 
 pub use each::Each;
-pub use for_::For;
 pub use get::Get;
 pub use length::Length;
 pub use lines::Lines;

crates/nu-parser/src/parser.rs

@@ -459,6 +459,10 @@ pub fn parse_internal_call(
 
     let signature = working_set.get_decl(decl_id).signature();
 
+    if signature.creates_scope {
+        working_set.enter_scope();
+    }
+
     // The index into the positional parameter in the definition
     let mut positional_idx = 0;
 
@@ -554,6 +558,10 @@ pub fn parse_internal_call(
     let err = check_call(command_span, &signature, &call);
     error = error.or(err);
 
+    if signature.creates_scope {
+        working_set.exit_scope();
+    }
+
     // FIXME: type unknown
     (Box::new(call), span(spans), error)
 }

crates/nu-protocol/src/signature.rs

@@ -36,6 +36,7 @@ pub struct Signature {
     pub rest_positional: Option<PositionalArg>,
     pub named: Vec<Flag>,
     pub is_filter: bool,
+    pub creates_scope: bool,
 }
 
 impl PartialEq for Signature {
@@ -62,6 +63,7 @@ impl Signature {
             rest_positional: None,
             named: vec![],
             is_filter: false,
+            creates_scope: false,
         }
     }
     pub fn build(name: impl Into<String>) -> Signature {
@@ -189,6 +191,12 @@ impl Signature {
         self
     }
 
+    /// Sets that signature will create a scope as it parses
+    pub fn creates_scope(mut self) -> Signature {
+        self.creates_scope = true;
+        self
+    }
+
     /// Get list of the short-hand flags
     pub fn get_shorts(&self) -> Vec<char> {
         self.named.iter().filter_map(|f| f.short).collect()

src/tests.rs

@@ -564,3 +564,8 @@ fn split_column() -> TestResult {
         "hello",
     )
 }
+
+#[test]
+fn for_loops() -> TestResult {
+    run_test(r#"(for x in [1, 2, 3] { $x + 10 }).1"#, "12")
+}