X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2Fmisc%2FMetaGrammar.java;h=656f878e2bb6793dc4cc8d824da81b1fbcec400b;hp=ab359c619396447ac72e7e355fb3b79ea692f493;hb=ea83c68e20abf2e74f901502a053b413b93e5289;hpb=eeba855277aa8280f844757b18b681bbea68b174

diff --git a/src/edu/berkeley/sbp/misc/MetaGrammar.java b/src/edu/berkeley/sbp/misc/MetaGrammar.java
index ab359c6..656f878 100644
--- a/src/edu/berkeley/sbp/misc/MetaGrammar.java
+++ b/src/edu/berkeley/sbp/misc/MetaGrammar.java
@@ -87,20 +87,15 @@ public class MetaGrammar extends ReflectiveWalker {
                                new PreSequence[] {
                                    new PreSequence(new Element[] { leftBrace(),
                                                                    p.buildUnion(),
-                                                                   rightBrace() })
+                                                                   rightBrace()
+                                   })
                                }
                            },
                            false,
                            false);
     }
 
-    public PreSequence rewrite(Object[] o)                     { return new PreSequence(o, null); }
-
-    public PreSequence seqx(PreSequence p, String tag) { return _equals__greater_(p, tag); }
-    public PreSequence _equals__greater_(PreSequence p, String tag) {
-        p.tag = tag;
-        return p;
-    }
+    public PreSequence _equals__greater_(PreSequence p, String tag) { p.tag = tag; return p; }
 
     public PreSequence ps(Object[] o) { return new PreSequence(o); }
     public PreSequence ps2(Object[] o1, String s, Object[] o2) {
@@ -124,11 +119,17 @@ public class MetaGrammar extends ReflectiveWalker {
     public Object _plus__plus_(final Element r)             { return Repeat.maximal(Repeat.many1(r)); }
     public Element _question_(final Element r)              { return Repeat.maybe(r); }
 
-    public MetaGrammar gram(Object o, MetaGrammar g, Object o2) { return g; }
-    public MetaGrammar  grammar(Object[] o) { return this; }
+    public Object walk(Tree<String> tree) {
+        String head = tree.head();
+        if (tree.numChildren()==0) return super.walk(tree);
+        if      ("\\n".equals(head)) return new Character('\n');
+        else if ("\\r".equals(head)) return new Character('\r');
+        else return super.walk(tree);
+    }
+
     public MetaGrammar grammar(Object o, Union[] u, Object x) { return this; }
-    public char    _backslash_n() { return '\n'; }
-    public char    _backslash_r() { return '\r'; }
+    public Object gram(Object o, Object g, Object o2) { return g; }
+    public MetaGrammar  grammar(Object[] o) { return this; }
     public Element    literal(String s) { Element ret = string(s); dropAll.add(ret); return ret; }
     public Range     _minus_(char a, char b) { return new Range(a, b); }
     public Range     range(char a)         { return new Range(a, a); }
@@ -143,6 +144,8 @@ public class MetaGrammar extends ReflectiveWalker {
         return set(ret);
     }
 
+    //////////////////////////////////////////////////////////////////////////////
+
     public class PreSequence {
         public final HashSet<Sequence> and  = new HashSet<Sequence>();
         public final HashSet<Sequence> not  = new HashSet<Sequence>();