---

yaml
---
r: 79500
b: refs/heads/snap-stage3
c: 1a06584
h: refs/heads/master
v: v3

Author: jbclements

[refs]

@@ -1,7 +1,7 @@
 ---
 refs/heads/master: 124eb2119c78651cfaaa7a046a101fa2e20f83ca
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
-refs/heads/snap-stage3: dc7f3df27fd17b41b3448f461138947db4c9bab2
+refs/heads/snap-stage3: 1a065841172a0824046b1f041bdb1134ba820db8
 refs/heads/try: ac820906c0e53eab79a98ee64f7231f57c3887b4
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b

branches/snap-stage3/src/libsyntax/ext/expand.rs

@@ -1410,6 +1410,17 @@ pub fn expand_crate(parse_sess: @mut parse::ParseSess,
     return ret;
 }
 
+// HYGIENIC CONTEXT EXTENSION:
+// all of these functions are for walking over
+// ASTs and making some change to the context of every
+// element that has one. a CtxtFn is a trait-ified
+// version of a closure in (SyntaxContext -> SyntaxContext).
+// the ones defined here include:
+// Renamer - add a rename to a context
+// MultiRenamer - add a set of renames to a context
+// Marker - add a mark to a context
+// Repainter - replace a context (maybe Replacer would be a better name?)
+
 // a function in SyntaxContext -> SyntaxContext
 pub trait CtxtFn{
     fn f(&self, ast::SyntaxContext) -> ast::SyntaxContext;