X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2Ftib%2FTib.java;h=9b4b97489a37d1577e9be97867398ee9ef13bb82;hp=59336df3787b36b744c4e0dc6a6f7ac0f3e666f3;hb=87f214f3da9f43c3ab93923313845c372f9a96be;hpb=bbaa9a17a69d38895efeb7ae6ddf03d73e64fd63

diff --git a/src/edu/berkeley/sbp/tib/Tib.java b/src/edu/berkeley/sbp/tib/Tib.java
index 59336df..9b4b974 100644
--- a/src/edu/berkeley/sbp/tib/Tib.java
+++ b/src/edu/berkeley/sbp/tib/Tib.java
@@ -289,23 +289,32 @@ public class Tib implements Token.Stream<CharToken> {
 
     public static class Grammar extends MetaGrammar {
         private int anon = 0;
+        private final Element ws = Repeat.maximal(Repeat.many0(nonTerminal("w")));
+        public Grammar() {
+            dropAll.add(ws);
+        }
         public Object walk(Tree<String> tree) {
             String head = tree.head();
             if (tree.numChildren()==0) return super.walk(tree);
-            if ("{".equals(head))
-                return nonTerminal("braced"+(anon++),
+            if ("{".equals(head)) {
+                String s = "braced"+(anon++);
+                Union u = nonTerminal(s);
+                Union u2 = ((PreSequence)walk(tree, 0)).sparse(ws).buildUnion();
+                u2.add(Sequence.singleton(new Element[] { u }, 0, null, null));
+                return nonTerminal(s,
                                    new PreSequence[][] {
                                        new PreSequence[] {
                                            new PreSequence(new Element[] { CharToken.leftBrace,
-                                                                           Repeat.maximal(Repeat.many0(nonTerminal("w"))),
-                                                                           ((PreSequence)walk(tree, 0)).buildUnion(),
-                                                                           Repeat.maximal(Repeat.many0(nonTerminal("w"))),
+                                                                           ws,
+                                                                           u2,
+                                                                           ws,
                                                                            CharToken.rightBrace
                                            })
                                        }
                                    },
                                    false,
                                    false);
+            }
             return super.walk(tree);
         }
     }