X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=src%2Fedu%2Fberkeley%2Fsbp%2Fmeta%2FMetaGrammarBindings.java;h=b0b86da4b86b33be7aaaeed99290b0d3029eada2;hb=fb8694140dd9736855795e64a9bd4c3d50f7f2ea;hp=cae45c0c75485ab94ba5e3fbf8bc634330200933;hpb=62be1c1ae2ac13086b508e34eeffdb7e536d5b61;p=sbp.git

diff --git a/src/edu/berkeley/sbp/meta/MetaGrammarBindings.java b/src/edu/berkeley/sbp/meta/MetaGrammarBindings.java
index cae45c0..b0b86da 100644
--- 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; }
@@ -266,6 +266,10 @@ 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); }
 
@@ -389,15 +393,19 @@ public class MetaGrammarBindings extends AnnotationGrammarBindings {
     public static @bind.as("~")   ElementNode tilde(final ElementNode e) {
         return new ElementNodeWrapper(e) {
                 public Atom toAtom(Context cx) {
-                    return infer((Topology<Character>)e.toAtom(cx).complement().minus(CharAtom.braces));
+                    return infer((Topology<Character>)e.toAtom(cx).complement()/*.minus(CharAtom.braces)*/);
                 }
                 public Element build(Context cx, NonTerminalNode cnt) {
-                    return infer((Topology<Character>)e.toAtom(cx).complement().minus(CharAtom.braces));
+                    return infer((Topology<Character>)e.toAtom(cx).complement()/*.minus(CharAtom.braces)*/);
                 } }; }
 
     public static @bind.as("Word")        String word(String s) { return s; }
     public static @bind.as("Quoted")      String quoted(String s) { return s; }
-    public static @bind.as("escaped")     String c(char c) { return c+""; }
+    public static @bind.as("escaped")     String c(char c) {
+        if (c=='{') return CharAtom.left+"";
+        if (c=='}') return CharAtom.right+"";
+        return c+"";
+    }
     public static @bind.as("EmptyString") String emptystring() { return ""; }
     public static @bind.as("\n")          String retur() { return "\n"; }
     public static @bind.as("\r")          String lf() { return "\r"; }