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.

Changed all the tests to use the new extern crate syntax

Change pretty printer to use 'as' syntax

Author: wickerwaka

src/doc/rust.md

@@ -891,9 +891,8 @@ There are several kinds of view item:
 ##### Extern crate declarations
 
 ~~~~ {.ebnf .gram}
-extern_crate_decl : "extern" "crate" ident [ '(' link_attrs ')' ] ? [ '=' string_lit ] ? ;
-link_attrs : link_attr [ ',' link_attrs ] + ;
-link_attr : ident '=' literal ;
+extern_crate_decl : "extern" "crate" crate_name
+crate_name: ident | ( string_lit as ident )
 ~~~~
 
 An _`extern crate` declaration_ specifies a dependency on an external crate.
@@ -913,11 +912,9 @@ Four examples of `extern crate` declarations:
 ~~~~ {.ignore}
 extern crate pcre;
 
-extern crate std; // equivalent to: extern crate std = "std";
+extern crate std; // equivalent to: extern crate std as std;
 
-extern crate ruststd = "std"; // linking to 'std' under another name
-
-extern crate foo = "some/where/rust-foo#foo:1.0"; // a full crate ID for external tools
+extern crate "std" as ruststd; // linking to 'std' under another name
 ~~~~
 
 ##### Use declarations

src/libsyntax/parse/parser.rs

@@ -4825,7 +4825,8 @@ 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,
@@ -4836,14 +4837,23 @@ 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())
                 } else {None};
 
                 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();

src/libsyntax/print/pprust.rs

@@ -2375,13 +2375,13 @@ 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) => {

src/test/auxiliary/crateresolve4b-1.rs

@@ -13,6 +13,6 @@
 #![crate_id="crateresolve4b#0.1"]
 #![crate_type = "lib"]
 
-extern crate crateresolve4a = "crateresolve4a#0.2";
+extern crate "crateresolve4a#0.2" as crateresolve4a;
 
 pub fn f() -> int { crateresolve4a::g() }

src/test/auxiliary/crateresolve4b-2.rs

@@ -13,6 +13,6 @@
 #![crate_id="crateresolve4b#0.2"]
 #![crate_type = "lib"]
 
-extern crate crateresolve4a = "crateresolve4a#0.1";
+extern crate "crateresolve4a#0.1" as crateresolve4a;
 
 pub fn g() -> int { crateresolve4a::f() }

src/test/auxiliary/issue-12133-dylib2.rs

@@ -12,6 +12,6 @@
 
 #![crate_type = "dylib"]
 
-extern crate a = "issue-12133-rlib";
-extern crate b = "issue-12133-dylib";
+extern crate "issue-12133-rlib" as a;
+extern crate "issue-12133-dylib" as b;
 

src/test/auxiliary/issue-13560-3.rs

@@ -13,6 +13,6 @@
 #![crate_type = "rlib"]
 #![feature(phase)]
 
-#[phase(plugin)] extern crate t1 = "issue-13560-1";
-#[phase(plugin, link)] extern crate t2 = "issue-13560-2";
+#[phase(plugin)] extern crate "issue-13560-1" as t1;
+#[phase(plugin, link)] extern crate "issue-13560-2" as t2;
 

src/test/auxiliary/issue-13620-2.rs

@@ -8,6 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern crate crate1 = "issue-13620-1";
+extern crate "issue-13620-1" as crate1;
 
 pub static FOO2: crate1::Foo = crate1::FOO;

src/test/auxiliary/issue-13872-2.rs

@@ -8,6 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern crate foo = "issue-13872-1";
+extern crate "issue-13872-1" as foo;
 
 pub use foo::B;

src/test/auxiliary/issue-13872-3.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern crate bar = "issue-13872-2";
+extern crate "issue-13872-2" as bar;
 
 use bar::B;