syntax: Permit visibility on tuple fields

This change is in preparation for #8122. Nothing is currently done with these
visibility qualifiers, they are just parsed and accepted by the compiler.

RFC: 0004-private-fields

5 files changed, 18 insertions, 9 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 24b8a345776..a7d458df0cf 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -1080,7 +1080,16 @@ pub type StructField = Spanned<StructField_>;
 #[deriving(Clone, Eq, TotalEq, Encodable, Decodable, Hash)]
 pub enum StructFieldKind {
     NamedField(Ident, Visibility),
-    UnnamedField // element of a tuple-like struct
+    UnnamedField(Visibility), // element of a tuple-like struct
+}
+
+impl StructFieldKind {
+    pub fn is_unnamed(&self) -> bool {
+        match *self {
+            UnnamedField(..) => true,
+            NamedField(..) => false,
+        }
+    }
 }
 
 #[deriving(Eq, TotalEq, Encodable, Decodable, Hash)]
diff --git a/src/libsyntax/ast_util.rs b/src/libsyntax/ast_util.rs
index 9d841255aa9..3dbd10b625c 100644
--- a/src/libsyntax/ast_util.rs
+++ b/src/libsyntax/ast_util.rs
@@ -290,8 +290,7 @@ pub fn split_trait_methods(trait_methods: &[TraitMethod])
 
 pub fn struct_field_visibility(field: ast::StructField) -> Visibility {
     match field.node.kind {
-        ast::NamedField(_, visibility) => visibility,
-        ast::UnnamedField => ast::Public
+        ast::NamedField(_, v) | ast::UnnamedField(v) => v
     }
 }
 
diff --git a/src/libsyntax/ext/deriving/generic.rs b/src/libsyntax/ext/deriving/generic.rs
index 89a8b2cd336..9c1d6a1d5ca 100644
--- a/src/libsyntax/ext/deriving/generic.rs
+++ b/src/libsyntax/ext/deriving/generic.rs
@@ -1007,7 +1007,7 @@ impl<'a> TraitDef<'a> {
             let sp = self.set_expn_info(cx, field.span);
             match field.node.kind {
                 ast::NamedField(ident, _) => named_idents.push((ident, sp)),
-                ast::UnnamedField => just_spans.push(sp),
+                ast::UnnamedField(..) => just_spans.push(sp),
             }
         }
 
@@ -1061,8 +1061,8 @@ impl<'a> TraitDef<'a> {
                     struct_type = Record;
                     Some(ident)
                 }
-                ast::UnnamedField if (struct_type == Unknown ||
-                                      struct_type == Tuple) => {
+                ast::UnnamedField(..) if (struct_type == Unknown ||
+                                          struct_type == Tuple) => {
                     struct_type = Tuple;
                     None
                 }
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index adf3ac0e17d..9b12987361e 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -3985,7 +3985,7 @@ impl<'a> Parser<'a> {
                 let attrs = p.parse_outer_attributes();
                 let lo = p.span.lo;
                 let struct_field_ = ast::StructField_ {
-                    kind: UnnamedField,
+                    kind: UnnamedField(p.parse_visibility()),
                     id: ast::DUMMY_NODE_ID,
                     ty: p.parse_ty(false),
                     attrs: attrs,
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index a9ab596b300..e1d6f821ba9 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -743,7 +743,8 @@ impl<'a> State<'a> {
                     |s, field| {
                         match field.node.kind {
                             ast::NamedField(..) => fail!("unexpected named field"),
-                            ast::UnnamedField => {
+                            ast::UnnamedField(vis) => {
+                                try!(s.print_visibility(vis));
                                 try!(s.maybe_print_comment(field.span.lo));
                                 s.print_type(field.node.ty)
                             }
@@ -762,7 +763,7 @@ impl<'a> State<'a> {
 
             for field in struct_def.fields.iter() {
                 match field.node.kind {
-                    ast::UnnamedField => fail!("unexpected unnamed field"),
+                    ast::UnnamedField(..) => fail!("unexpected unnamed field"),
                     ast::NamedField(ident, visibility) => {
                         try!(self.hardbreak_if_not_bol());
                         try!(self.maybe_print_comment(field.span.lo));