auto merge of #16689 : wickerwaka/rust/crate-as, r=pcwalton

For review. Not sure about the link_attrs stuff. Will work on converting all the tests.

extern crate "foobar" as foo;
extern crate foobar as foo;

Implements remaining part of RFC #47.
Addresses issue #16461.

Removed link_attrs from rust.md, they don't appear to be supported by
the parser.

2 files changed, 15 insertions, 5 deletions

diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 01de001c043..816700681cf 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -4807,7 +4807,8 @@ impl<'a> Parser<'a> {
     /// # Example
     ///
     /// extern crate url;
-    /// extern crate foo = "bar";
+    /// extern crate foo = "bar"; //deprecated
+    /// extern crate "bar" as foo;
     fn parse_item_extern_crate(&mut self,
                                 lo: BytePos,
                                 visibility: Visibility,
@@ -4818,6 +4819,8 @@ impl<'a> Parser<'a> {
             token::IDENT(..) => {
                 let the_ident = self.parse_ident();
                 self.expect_one_of(&[], &[token::EQ, token::SEMI]);
+                // NOTE - #16689 change this to a warning once
+                //        the 'as' support is in stage0
                 let path = if self.token == token::EQ {
                     self.bump();
                     Some(self.parse_str())
@@ -4825,7 +4828,14 @@ impl<'a> Parser<'a> {
 
                 self.expect(&token::SEMI);
                 (path, the_ident)
-            }
+            },
+            token::LIT_STR(..) | token::LIT_STR_RAW(..) => {
+                let path = self.parse_str();
+                self.expect_keyword(keywords::As);
+                let the_ident = self.parse_ident();
+                self.expect(&token::SEMI);
+                (Some(path), the_ident)
+            },
             _ => {
                 let span = self.span;
                 let token_str = self.this_token_to_string();
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index d5b6c5652a0..41f95fa75f5 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -2363,13 +2363,13 @@ impl<'a> State<'a> {
         match item.node {
             ast::ViewItemExternCrate(id, ref optional_path, _) => {
                 try!(self.head("extern crate"));
-                try!(self.print_ident(id));
                 for &(ref p, style) in optional_path.iter() {
+                    try!(self.print_string(p.get(), style));
                     try!(space(&mut self.s));
-                    try!(word(&mut self.s, "="));
+                    try!(word(&mut self.s, "as"));
                     try!(space(&mut self.s));
-                    try!(self.print_string(p.get(), style));
                 }
+                try!(self.print_ident(id));
             }
 
             ast::ViewItemUse(ref vp) => {