---

yaml
---
r: 152918
b: refs/heads/try2
c: 268f6c5
h: refs/heads/master
v: v3

Author: jbclements

[refs]

@@ -5,7 +5,7 @@ refs/heads/snap-stage3: 78a7676898d9f80ab540c6df5d4c9ce35bb50463
 refs/heads/try: 519addf6277dbafccbb4159db4b710c37eaa2ec5
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
-refs/heads/try2: 351a5fd2b40c2be90f94fe2580903e93353b95ee
+refs/heads/try2: 268f6c56c219e97b444d78dadc387cc549e27aa6
 refs/heads/dist-snap: ba4081a5a8573875fed17545846f6f6902c8ba8d
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503

branches/try2/src/libsyntax/fold.rs

@@ -391,23 +391,6 @@ fn fold_arg_<T: Folder>(a: &Arg, fld: &mut T) -> Arg {
 
 // build a new vector of tts by appling the Folder's fold_ident to
 // all of the identifiers in the token trees.
-//
-// This is part of hygiene magic. As far as hygiene is concerned, there
-// are three types of let pattern bindings or loop labels:
-//      - those defined and used in non-macro part of the program
-//      - those used as part of macro invocation arguments
-//      - those defined and used inside macro definitions
-// Lexically, type 1 and 2 are in one group and type 3 the other. If they
-// clash, in order for let and loop label to work hygienically, one group
-// or the other needs to be renamed. The problem is that type 2 and 3 are
-// parsed together (inside the macro expand function). After being parsed and
-// AST being constructed, they can no longer be distinguished from each other.
-//
-// For that reason, type 2 let bindings and loop labels are actually renamed
-// in the form of tokens instead of AST nodes, here. There are wasted effort
-// since many token::IDENT are not necessary part of let bindings and most
-// token::LIFETIME are certainly not loop labels. But we can't tell in their
-// token form. So this is less ideal and hacky but it works.
 pub fn fold_tts<T: Folder>(tts: &[TokenTree], fld: &mut T) -> Vec<TokenTree> {
     tts.iter().map(|tt| {
         match *tt {