---

yaml
---
r: 79370
b: refs/heads/try
c: a2384b6
h: refs/heads/master
v: v3

Author: jbclements

[refs]

@@ -2,7 +2,7 @@
 refs/heads/master: 3e6de6b7da8ee88bf84b0e217900051334be08da
 refs/heads/snap-stage1: e33de59e47c5076a89eadeb38f4934f58a3618a6
 refs/heads/snap-stage3: 60fba4d7d677ec098e6a43014132fe99f7547363
-refs/heads/try: ab2e83dd8753833ee572210c20876b0583f6d37e
+refs/heads/try: a2384b65e0eff63675a301ca2e340557de487c8c
 refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
 refs/heads/try2: 147ecfdd8221e4a4d4e090486829a06da1e0ca3c

branches/try/src/libsyntax/ast.rs

@@ -70,6 +70,15 @@ impl Eq for Ident {
 // storage.
 pub type SyntaxContext = uint;
 
+// the SCTable contains a table of SyntaxContext_'s. It
+// represents a flattened tree structure, to avoid having
+// managed pointers everywhere (that caused an ICE).
+// the mark_memo and rename_memo fields are side-tables
+// that ensure that adding the same mark to the same context
+// gives you back the same context as before. This shouldn't
+// change the semantics--everything here is immutable--but
+// it should cut down on memory use *a lot*; applying a mark
+// to a tree containing 50 identifiers would otherwise generate
 pub struct SCTable {
     table : ~[SyntaxContext_],
     mark_memo : HashMap<(SyntaxContext,Mrk),SyntaxContext>,