add backslash to braces in metagrammar

[sbp.git] / src / edu / berkeley / sbp / meta / MetaGrammarBindings.java

diff --git a/src/edu/berkeley/sbp/meta/MetaGrammarBindings.java b/src/edu/berkeley/sbp/meta/MetaGrammarBindings.java
index c51f71f..4ae0393 100644 (file)
--- a/src/edu/berkeley/sbp/meta/MetaGrammarBindings.java
+++ b/src/edu/berkeley/sbp/meta/MetaGrammarBindings.java
@@ -195,7 +195,7 @@ public class MetaGrammarBindings extends AnnotationGrammarBindings {
         public Seq(ElementNode e) { this(new ElementNode[] { e }); }
         public Seq(ElementNode[] elements) { this.elements = elements; }
         public Atom toAtom(Context cx) {
-            if (elements.length != 1) throw new Error("FIXME");
+            if (elements.length != 1) throw new Error("you attempted to use ->, **, ++, or a similar character-class operator on a [potentially] multicharacter production");
             return elements[0].toAtom(cx);
         }
         public Seq tag(String tag) { this.tag = prefix+tag; return this; }
@@ -225,9 +225,9 @@ public class MetaGrammarBindings extends AnnotationGrammarBindings {
         }
         public Sequence build(Context cx, Union u, NonTerminalNode cnt) {
             Sequence ret = build0(cx, cnt);
-            for(Seq s : and) { Sequence dork = s.build(cx, u, cnt); ret = ret.and(dork); }
-            for(Seq s : not) { Sequence dork = s.build(cx, u, cnt); ret = ret.andnot(dork); }
-            u.add(ret);
+            for(Seq s : and) { Sequence dork = s.build(cx, null, cnt); ret = ret.and(dork); }
+            for(Seq s : not) { Sequence dork = s.build(cx, null, cnt); ret = ret.andnot(dork); }
+            if (u!=null) u.add(ret);
             return ret;
         }
         public Sequence build0(Context cx, NonTerminalNode cnt) {
@@ -266,10 +266,6 @@ public class MetaGrammarBindings extends AnnotationGrammarBindings {
     public static @bind.as("Elements")  Seq  seq2(ElementNode[] elements)               { return new Seq(elements); }
     public static @bind.as        Seq  psx(Seq s)                        { return s; }
     public static @bind.as(":")   ElementNode   colon(String s, ElementNode e)             { return new Label(s, e); }
-    public static @bind.as("{") ElementNode   leftBrace() {
-        return new Drop(new CharClass(new Range[] { new Range(CharAtom.left, CharAtom.left) })); }
-    public static @bind.as("}") ElementNode   rightBrace() {
-        return new Drop(new CharClass(new Range[] { new Range(CharAtom.right, CharAtom.right) })); }
     public static @bind.as(")")   void close(String foo)                 { throw new Error("not supported"); }
     public static @bind.as("()")  ElementNode   epsilon()                         { return new Constant(epsilon); }