Implement tuple and tuple struct indexing

This allows code to access the fields of tuples and tuple structs:

    let x = (1i, 2i);
    assert_eq!(x.1, 2);

    struct Point(int, int);
    let origin = Point(0, 0);
    assert_eq!(origin.0, 0);
    assert_eq!(origin.1, 0);

1 files changed, 13 insertions, 0 deletions

diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index 7deabed04b8..30b7317fa56 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -134,6 +134,10 @@ pub trait Folder {
         noop_fold_ident(i, self)
     }
 
+    fn fold_uint(&mut self, i: uint) -> uint {
+        noop_fold_uint(i, self)
+    }
+
     fn fold_path(&mut self, p: &Path) -> Path {
         noop_fold_path(p, self)
     }
@@ -466,6 +470,10 @@ pub fn noop_fold_ident<T: Folder>(i: Ident, _: &mut T) -> Ident {
     i
 }
 
+pub fn noop_fold_uint<T: Folder>(i: uint, _: &mut T) -> uint {
+    i
+}
+
 pub fn noop_fold_path<T: Folder>(p: &Path, fld: &mut T) -> Path {
     ast::Path {
         span: fld.new_span(p.span),
@@ -1180,6 +1188,11 @@ pub fn noop_fold_expr<T: Folder>(e: Gc<Expr>, folder: &mut T) -> Gc<Expr> {
                       respan(id.span, folder.fold_ident(id.node)),
                       tys.iter().map(|&x| folder.fold_ty(x)).collect())
         }
+        ExprTupField(el, id, ref tys) => {
+            ExprTupField(folder.fold_expr(el),
+                      respan(id.span, folder.fold_uint(id.node)),
+                      tys.iter().map(|&x| folder.fold_ty(x)).collect())
+        }
         ExprIndex(el, er) => {
             ExprIndex(folder.fold_expr(el), folder.fold_expr(er))
         }