Implement bytes! syntax extension

src/libsyntax/ext/base.rs

@@ -139,6 +139,8 @@ pub fn syntax_expander_table() -> SyntaxEnv {
         @SE(ItemDecorator(ext::auto_encode::expand_auto_decode)));
     syntax_expanders.insert(@~"env",
                             builtin_normal_tt(ext::env::expand_syntax_ext));
+    syntax_expanders.insert(@~"bytes",
+                            builtin_normal_tt(ext::bytes::expand_syntax_ext));
     syntax_expanders.insert(@~"concat_idents",
                             builtin_normal_tt(
                                 ext::concat_idents::expand_syntax_ext));

src/libsyntax/ext/bytes.rs

@@ -0,0 +1,28 @@
+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+/* The compiler code necessary to support the bytes! extension. */
+
+use ast;
+use codemap::span;
+use ext::base::*;
+use ext::base;
+use ext::build::{mk_u8, mk_slice_vec_e};
+
+pub fn expand_syntax_ext(cx: @ext_ctxt, sp: span, tts: &[ast::token_tree])
+    -> base::MacResult {
+    let var = get_single_str_from_tts(cx, sp, tts, "bytes!");
+    let mut bytes = ~[];
+    for var.each |byte| {
+        bytes.push(mk_u8(cx, sp, byte));
+    }
+    let e = mk_slice_vec_e(cx, sp, bytes);
+    MRExpr(e)
+}

src/libsyntax/syntax.rc

@@ -78,6 +78,7 @@ pub mod ext {
 
     pub mod fmt;
     pub mod env;
+    pub mod bytes;
     pub mod concat_idents;
     pub mod log_syntax;
     pub mod auto_encode;

src/test/run-pass/syntax-extension-bytes.rs

@@ -0,0 +1,16 @@
+// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+fn main() {
+    let vec = bytes!("abc");
+    assert_eq!(vec[0], 97);
+    assert_eq!(vec[1], 98);
+    assert_eq!(vec[2], 99);
+}