Make type in ast::Local optional

7 files changed, 20 insertions, 22 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 12432c8c78f..93750867750 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -643,8 +643,8 @@ pub enum LocalSource {
 /// Local represents a `let` statement, e.g., `let <pat>:<ty> = <expr>;`
 #[deriving(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Show)]
 pub struct Local {
-    pub ty: P<Ty>,
     pub pat: P<Pat>,
+    pub ty: Option<P<Ty>>,
     pub init: Option<P<Expr>>,
     pub id: NodeId,
     pub span: Span,
diff --git a/src/libsyntax/ext/build.rs b/src/libsyntax/ext/build.rs
index 239af188909..ea345f3a458 100644
--- a/src/libsyntax/ext/build.rs
+++ b/src/libsyntax/ext/build.rs
@@ -482,8 +482,8 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
             self.pat_ident(sp, ident)
         };
         let local = P(ast::Local {
-            ty: self.ty_infer(sp),
             pat: pat,
+            ty: None,
             init: Some(ex),
             id: ast::DUMMY_NODE_ID,
             span: sp,
@@ -506,8 +506,8 @@ impl<'a> AstBuilder for ExtCtxt<'a> {
             self.pat_ident(sp, ident)
         };
         let local = P(ast::Local {
-            ty: typ,
             pat: pat,
+            ty: Some(typ),
             init: Some(ex),
             id: ast::DUMMY_NODE_ID,
             span: sp,
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index 5de7068563d..dcf25a26e2c 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -712,7 +712,7 @@ fn expand_non_macro_stmt(Spanned {node, span: stmt_span}: Stmt, fld: &mut MacroE
                 let rewritten_local = local.map(|Local {id, pat, ty, init, source, span}| {
                     // expand the ty since TyFixedLengthVec contains an Expr
                     // and thus may have a macro use
-                    let expanded_ty = fld.fold_ty(ty);
+                    let expanded_ty = ty.map(|t| fld.fold_ty(t));
                     // expand the pat (it might contain macro uses):
                     let expanded_pat = fld.fold_pat(pat);
                     // find the PatIdents in the pattern:
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index 4f0169e31f2..c134b11a0eb 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -553,7 +553,7 @@ pub fn noop_fold_parenthesized_parameter_data<T: Folder>(data: ParenthesizedPara
 pub fn noop_fold_local<T: Folder>(l: P<Local>, fld: &mut T) -> P<Local> {
     l.map(|Local {id, pat, ty, init, source, span}| Local {
         id: fld.new_id(id),
-        ty: fld.fold_ty(ty),
+        ty: ty.map(|t| fld.fold_ty(t)),
         pat: fld.fold_pat(pat),
         init: init.map(|e| fld.fold_expr(e)),
         source: source,
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 457085f5cc8..c7327a24bb6 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -3627,13 +3627,9 @@ impl<'a> Parser<'a> {
         let lo = self.span.lo;
         let pat = self.parse_pat();
 
-        let mut ty = P(Ty {
-            id: ast::DUMMY_NODE_ID,
-            node: TyInfer,
-            span: mk_sp(lo, lo),
-        });
+        let mut ty = None;
         if self.eat(&token::Colon) {
-            ty = self.parse_ty_sum();
+            ty = Some(self.parse_ty_sum());
         }
         let init = self.parse_initializer();
         P(ast::Local {
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 02a03285d3b..3f3af4ed709 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -1858,13 +1858,11 @@ impl<'a> State<'a> {
 
     pub fn print_local_decl(&mut self, loc: &ast::Local) -> IoResult<()> {
         try!(self.print_pat(&*loc.pat));
-        match loc.ty.node {
-            ast::TyInfer => Ok(()),
-            _ => {
-                try!(self.word_space(":"));
-                self.print_type(&*loc.ty)
-            }
+        if let Some(ref ty) = loc.ty {
+            try!(self.word_space(":"));
+            try!(self.print_type(&**ty));
         }
+        Ok(())
     }
 
     pub fn print_decl(&mut self, decl: &ast::Decl) -> IoResult<()> {
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index 40ca6354ca6..e532c76347f 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -211,7 +211,7 @@ pub fn walk_view_item<'v, V: Visitor<'v>>(visitor: &mut V, vi: &'v ViewItem) {
 
 pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local) {
     visitor.visit_pat(&*local.pat);
-    visitor.visit_ty(&*local.ty);
+    walk_ty_opt(visitor, &local.ty);
     walk_expr_opt(visitor, &local.init);
 }
 
@@ -381,6 +381,13 @@ pub fn skip_ty<'v, V: Visitor<'v>>(_: &mut V, _: &'v Ty) {
     // Empty!
 }
 
+pub fn walk_ty_opt<'v, V: Visitor<'v>>(visitor: &mut V, optional_type: &'v Option<P<Ty>>) {
+    match *optional_type {
+        Some(ref ty) => visitor.visit_ty(&**ty),
+        None => ()
+    }
+}
+
 pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty) {
     match typ.node {
         TyVec(ref ty) | TyParen(ref ty) => {
@@ -583,10 +590,7 @@ pub fn walk_ty_param_bound<'v, V: Visitor<'v>>(visitor: &mut V,
 pub fn walk_ty_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v TyParam) {
     visitor.visit_ident(param.span, param.ident);
     walk_ty_param_bounds_helper(visitor, &param.bounds);
-    match param.default {
-        Some(ref ty) => visitor.visit_ty(&**ty),
-        None => {}
-    }
+    walk_ty_opt(visitor, &param.default);
 }
 
 pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics) {