parse: refactor fun ret ty & param ty

4 files changed, 28 insertions, 61 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 5866f9db078..d90d74d7a26 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -254,7 +254,7 @@ pub struct ParenthesizedArgs {
     pub inputs: Vec<P<Ty>>,
 
     /// `C`
-    pub output: Option<P<Ty>>,
+    pub output: FunctionRetTy,
 }
 
 impl ParenthesizedArgs {
@@ -2185,7 +2185,7 @@ impl fmt::Debug for ImplPolarity {
 }
 
 #[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
-pub enum FunctionRetTy {
+pub enum FunctionRetTy { // FIXME(Centril): Rename to `FnRetTy` and in HIR also.
     /// Returns type is not specified.
     ///
     /// Functions default to `()` and closures default to inference.
diff --git a/src/libsyntax/mut_visit.rs b/src/libsyntax/mut_visit.rs
index bb0462c19cd..97a85b0fe7e 100644
--- a/src/libsyntax/mut_visit.rs
+++ b/src/libsyntax/mut_visit.rs
@@ -553,7 +553,7 @@ pub fn noop_visit_parenthesized_parameter_data<T: MutVisitor>(args: &mut Parenth
                                                               vis: &mut T) {
     let ParenthesizedArgs { inputs, output, span } = args;
     visit_vec(inputs, |input| vis.visit_ty(input));
-    visit_opt(output, |output| vis.visit_ty(output));
+    noop_visit_fn_ret_ty(output, vis);
     vis.visit_span(span);
 }
 
@@ -742,7 +742,11 @@ pub fn noop_visit_asyncness<T: MutVisitor>(asyncness: &mut IsAsync, vis: &mut T)
 pub fn noop_visit_fn_decl<T: MutVisitor>(decl: &mut P<FnDecl>, vis: &mut T) {
     let FnDecl { inputs, output } = decl.deref_mut();
     inputs.flat_map_in_place(|param| vis.flat_map_param(param));
-    match output {
+    noop_visit_fn_ret_ty(output, vis);
+}
+
+pub fn noop_visit_fn_ret_ty<T: MutVisitor>(fn_ret_ty: &mut FunctionRetTy, vis: &mut T) {
+    match fn_ret_ty {
         FunctionRetTy::Default(span) => vis.visit_span(span),
         FunctionRetTy::Ty(ty) => vis.visit_ty(ty),
     }
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 03e394b8c7e..a141d4d71bb 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -887,17 +887,9 @@ impl<'a> PrintState<'a> for State<'a> {
 
             ast::GenericArgs::Parenthesized(ref data) => {
                 self.s.word("(");
-                self.commasep(
-                    Inconsistent,
-                    &data.inputs,
-                    |s, ty| s.print_type(ty));
+                self.commasep(Inconsistent, &data.inputs, |s, ty| s.print_type(ty));
                 self.s.word(")");
-
-                if let Some(ref ty) = data.output {
-                    self.space_if_not_bol();
-                    self.word_space("->");
-                    self.print_type(ty);
-                }
+                self.print_fn_ret_ty(&data.output);
             }
         }
     }
@@ -1579,6 +1571,7 @@ impl<'a> State<'a> {
         self.ann.post(self, AnnNode::SubItem(ti.id))
     }
 
+    // FIXME(Centril): merge with function above.
     crate fn print_impl_item(&mut self, ii: &ast::ImplItem) {
         self.ann.pre(self, AnnNode::SubItem(ii.id));
         self.hardbreak_if_not_bol();
@@ -2104,7 +2097,7 @@ impl<'a> State<'a> {
                 self.print_asyncness(asyncness);
                 self.print_capture_clause(capture_clause);
 
-                self.print_fn_block_params(decl);
+                self.print_fn_params_and_ret(decl, true);
                 self.s.space();
                 self.print_expr(body);
                 self.end(); // need to close a box
@@ -2535,36 +2528,16 @@ impl<'a> State<'a> {
             self.print_ident(name);
         }
         self.print_generic_params(&generics.params);
-        self.print_fn_params_and_ret(decl);
+        self.print_fn_params_and_ret(decl, false);
         self.print_where_clause(&generics.where_clause)
     }
 
-    crate fn print_fn_params_and_ret(&mut self, decl: &ast::FnDecl) {
-        self.popen();
-        self.commasep(Inconsistent, &decl.inputs, |s, param| s.print_param(param, false));
-        self.pclose();
-
-        self.print_fn_output(decl)
-    }
-
-    crate fn print_fn_block_params(&mut self, decl: &ast::FnDecl) {
-        self.s.word("|");
-        self.commasep(Inconsistent, &decl.inputs, |s, param| s.print_param(param, true));
-        self.s.word("|");
-
-        if let ast::FunctionRetTy::Default(..) = decl.output {
-            return;
-        }
-
-        self.space_if_not_bol();
-        self.word_space("->");
-        match decl.output {
-            ast::FunctionRetTy::Ty(ref ty) => {
-                self.print_type(ty);
-                self.maybe_print_comment(ty.span.lo())
-            }
-            ast::FunctionRetTy::Default(..) => unreachable!(),
-        }
+    crate fn print_fn_params_and_ret(&mut self, decl: &ast::FnDecl, is_closure: bool) {
+        let (open, close) = if is_closure { ("|", "|") } else { ("(", ")") };
+        self.word(open);
+        self.commasep(Inconsistent, &decl.inputs, |s, param| s.print_param(param, is_closure));
+        self.word(close);
+        self.print_fn_ret_ty(&decl.output)
     }
 
     crate fn print_movability(&mut self, movability: ast::Movability) {
@@ -2786,24 +2759,14 @@ impl<'a> State<'a> {
         self.end();
     }
 
-    crate fn print_fn_output(&mut self, decl: &ast::FnDecl) {
-        if let ast::FunctionRetTy::Default(..) = decl.output {
-            return;
-        }
-
-        self.space_if_not_bol();
-        self.ibox(INDENT_UNIT);
-        self.word_space("->");
-        match decl.output {
-            ast::FunctionRetTy::Default(..) => unreachable!(),
-            ast::FunctionRetTy::Ty(ref ty) =>
-                self.print_type(ty),
-        }
-        self.end();
-
-        match decl.output {
-            ast::FunctionRetTy::Ty(ref output) => self.maybe_print_comment(output.span.lo()),
-            _ => {}
+    crate fn print_fn_ret_ty(&mut self, fn_ret_ty: &ast::FunctionRetTy) {
+        if let ast::FunctionRetTy::Ty(ty) = fn_ret_ty {
+            self.space_if_not_bol();
+            self.ibox(INDENT_UNIT);
+            self.word_space("->");
+            self.print_type(ty);
+            self.end();
+            self.maybe_print_comment(ty.span.lo());
         }
     }
 
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index 7cc1a769e52..74df808b37e 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -420,7 +420,7 @@ pub fn walk_generic_args<'a, V>(visitor: &mut V,
         }
         GenericArgs::Parenthesized(ref data) => {
             walk_list!(visitor, visit_ty, &data.inputs);
-            walk_list!(visitor, visit_ty, &data.output);
+            walk_fn_ret_ty(visitor, &data.output);
         }
     }
 }