libsyntax: Implement the new box syntax for unique pointers.

Author: pcwalton

src/libsyntax/parse/parser.rs

@@ -2326,6 +2326,22 @@ impl Parser {
               _ => self.mk_unary(UnUniq, e)
             };
           }
+          token::IDENT(_, _) if self.is_keyword(keywords::Box) => {
+            self.bump();
+
+            let subexpression = self.parse_prefix_expr();
+            hi = subexpression.span.hi;
+            // HACK: turn `box [...]` into a boxed-evec
+            ex = match subexpression.node {
+                ExprVec(..) |
+                ExprLit(@codemap::Spanned {
+                    node: lit_str(..),
+                    span: _
+                }) |
+                ExprRepeat(..) => ExprVstore(subexpression, ExprVstoreUniq),
+                _ => self.mk_unary(UnUniq, subexpression)
+            };
+          }
           _ => return self.parse_dot_or_call_expr()
         }
         return self.mk_expr(lo, hi, ex);

src/libsyntax/parse/token.rs

@@ -465,15 +465,17 @@ declare_special_idents_and_keywords! {
         (45,                         While,      "while");
         (46,                         Continue,   "continue");
         (47,                         Proc,       "proc");
+        (48,                         Box,        "box");
 
         'reserved:
-        (48,                         Alignof,    "alignof");
-        (49,                         Be,         "be");
-        (50,                         Offsetof,   "offsetof");
-        (51,                         Pure,       "pure");
-        (52,                         Sizeof,     "sizeof");
-        (53,                         Typeof,     "typeof");
-        (54,                         Yield,      "yield");
+        (49,                         Alignof,    "alignof");
+        (50,                         Be,         "be");
+        (51,                         Offsetof,   "offsetof");
+        (52,                         Pure,       "pure");
+        (53,                         Sizeof,     "sizeof");
+        (54,                         Typeof,     "typeof");
+        (55,                         Unsized,    "unsized");
+        (56,                         Yield,      "yield");
     }
 }
 

src/test/run-pass/new-box-syntax.rs

@@ -0,0 +1,8 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+fn main() {
+    let x: ~int = box 3;
+    println!("{}", *x);
+}
+