X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2Fmeta%2FGrammarAST.java;h=1c1ef3de09dfb6302742049d243cee5e80c35fae;hp=046c3ac6a039f1a24110bb0493d62649e6da95a4;hb=fec264a3cce7bb2f0016343c86c3cc63d7321eac;hpb=5fa948c7db9597445448194418537a1c74f46a27

diff --git a/src/edu/berkeley/sbp/meta/GrammarAST.java b/src/edu/berkeley/sbp/meta/GrammarAST.java
index 046c3ac..1c1ef3d 100644
--- a/src/edu/berkeley/sbp/meta/GrammarAST.java
+++ b/src/edu/berkeley/sbp/meta/GrammarAST.java
@@ -96,6 +96,7 @@ public class GrammarAST {
         if (head.equals("Elements")) return new Seq((ElementNode[])Reflection.rebuild(walkChildren(t), ElementNode[].class));
         if (head.equals("NonTerminalReference")) return new ReferenceNode(stringifyChildren(t.child(0)));
         if (head.equals(")"))   return new ReferenceNode(stringifyChildren(t.child(0)), true);
+        if (head.equals(":"))   return new LabelNode(stringifyChildren(t.child(0)), walkElement(t.child(1)));
         if (head.equals("::"))  return walkSeq(t.child(1)).tag(walkString(t.child(0)));
         if (head.equals("...")) return new DropNode(new RepeatNode(new TildeNode(new AtomNode()), null, true,  true,  false));
 
@@ -137,6 +138,7 @@ public class GrammarAST {
         }
         if (head.equals("\"\"")) return "";
         if (head.equals("\n"))   return "\n";
+        if (head.equals("\t"))   return "\t";
         if (head.equals("\r"))   return "\r";
         if (head.equals("SubGrammar")) return GrammarAST.buildFromAST(t.child(0), "s", resolver);
         if (head.equals("NonTerminal"))
@@ -212,104 +214,45 @@ public class GrammarAST {
         }
     }
 
-    /** a node in the AST which is resolved into an Element */
-    private abstract class ElementNode {
-        public boolean isLifted() { return false; }
-        public boolean isDropped(Context cx) { return false; }
-        public Atom toAtom(Context cx) { throw new Error("can't convert a " + this.getClass().getName() + " to an atom: " + this); }
-        public abstract Element build(Context cx, NonTerminalNode cnt, boolean dropall);
-    }
-
-    private class UnionNode extends ElementNode {
-        public Seq[][] sequences;
-        public String  sep = null;
-        public boolean rep;
-        public UnionNode(Seq seq) { this(new Seq[][] { new Seq[] { seq } }); }
-        public UnionNode(Seq[][] sequences) { this(sequences, false, null); }
-        public UnionNode(Seq[][] sequences, boolean rep, String sep) {
-            this.sequences = sequences;
-            this.rep = rep;
-            this.sep = sep;
-        }
-        public boolean isDropped(Context cx) {
-            for(Seq[] seqs : sequences)
-                for(Seq seq : seqs)
-                    if (!seq.isDropped(cx))
-                        return false;
-            return true;
-        }
-        public Atom toAtom(Context cx) {
-            Atom ret = null;
-            for(Seq[] ss : sequences)
-                for(Seq s : ss)
-                    ret = ret==null ? s.toAtom(cx) : (Atom)ret.union(s.toAtom(cx));
-            return ret;
-        }
-        public Element build(Context cx, NonTerminalNode cnt, boolean dropall) {
-            return buildIntoPreallocatedUnion(cx, cnt, dropall, new Union(null, false)); }
-        public Element buildIntoPreallocatedUnion(Context cx, NonTerminalNode cnt, boolean dropall, Union u) {
-            Union urep = null;
-            if (rep) {
-                urep = new Union(null, false);
-                urep.add(Sequence.create(cnt.name, new Element[0]));
-                urep.add(sep==null
-                         ? Sequence.create(new Element[] { u }, 0)
-                         : Sequence.create(new Element[] { cx.get(sep), u }, 1));
-            }
-            HashSet<Sequence> bad2 = new HashSet<Sequence>();
-            for(int i=0; i<sequences.length; i++) {
-                Seq[] group = sequences[i];
-                Union u2 = new Union(null, false);
-                if (sequences.length==1) u2 = u;
-                for(int j=0; j<group.length; j++)
-                    if (!rep)
-                        group[j].build(cx, u2, cnt, dropall);
-                    else {
-                        Union u3 = new Union(null, false);
-                        group[j].build(cx, u3, cnt, dropall);
-                        Sequence s = Sequence.create(cnt.name,
-                                                     new Element[] { u3, urep },
-                                                     new boolean[] { false, false },
-                                                     new boolean[] { false, true});
-                        u2.add(s);
-                    }
-                if (sequences.length==1) break;
-                Sequence seq = Sequence.create(u2);
-                for(Sequence s : bad2) seq = seq.andnot(s);
-                u.add(seq);
-                bad2.add(Sequence.create(u2));
-            }
-            return u;
-        }
-    }
-
-    private class NonTerminalNode extends UnionNode {
-        public boolean alwaysDrop;
-        public String  name = null;
-        public boolean isDropped(Context cx) { return alwaysDrop; }
+    /** a NonTerminal is always a union at the top level */
+    private class NonTerminalNode {
+        public final boolean alwaysDrop;
+        public final String  name;
+        public final ElementNode elementNode;
+        public final UnionNode unionNode;
         public NonTerminalNode(String name, Seq[][] sequences, boolean rep, String sep, boolean alwaysDrop) {
-            super(sequences, rep, sep==null?null:(prefix + sep));
             this.name = prefix + name;
             this.alwaysDrop = alwaysDrop;
+            this.unionNode = new UnionNode(sequences, rep, sep==null?null:(prefix + sep));
+            this.elementNode = alwaysDrop ? new DropNode(unionNode) : unionNode;
         }
+        public boolean isDropped(Context cx) { return alwaysDrop; }
         public Element build(Context cx, NonTerminalNode cnt, boolean dropall) { return cx.get(name); }
+        public ElementNode getElementNode() { return elementNode; }
+        public UnionNode   getUnionNode() { return unionNode; }
     }
 
+    /** a sequence */
     private class Seq {
+        /** elements of the sequence */
+        ElementNode[] elements;
+        /** follow-set, if explicit */
+        ElementNode follow;
+        /** tag to add when building the AST */
+        String tag = null;
+        /** positive conjuncts */
+        HashSet<Seq> and = new HashSet<Seq>();
+        /** negative conjuncts */
+        HashSet<Seq> not = new HashSet<Seq>();
         public boolean alwaysDrop = false;
         public boolean isDropped(Context cx) {
             if (alwaysDrop) return true;
             if (tag!=null) return false;
             for(int i=0; i<elements.length; i++)
-                if (!elements[i].isDropped(cx))
+                if (!elements[i].isDropped(cx) || ((elements[i] instanceof LiteralNode) && ((LiteralNode)elements[i]).caret))
                     return false;
             return true;
         }
-        HashSet<Seq> and = new HashSet<Seq>();
-        HashSet<Seq> not = new HashSet<Seq>();
-        ElementNode[] elements;
-        ElementNode follow;
-        String tag = null;
         public Seq(ElementNode e) { this(new ElementNode[] { e }); }
         public Seq(ElementNode[] elements) { this(elements, true); }
         public Seq(ElementNode[] el, boolean check) {
@@ -412,6 +355,91 @@ public class GrammarAST {
         }
     }
 
+    /** a node in the AST which is resolved into an Element */
+    private abstract class ElementNode {
+        /** the field name to be used when synthesizing AST classes; null if none suggested */
+        public String getFieldName() { return null; }
+        public boolean isLifted() { return false; }
+        public boolean isDropped(Context cx) { return false; }
+        public Atom toAtom(Context cx) { throw new Error("can't convert a " + this.getClass().getName() + " to an atom: " + this); }
+        public abstract Element build(Context cx, NonTerminalNode cnt, boolean dropall);
+    }
+
+    /** a union, produced by a ( .. | .. | .. ) construct */
+    private class UnionNode extends ElementNode {
+
+        /** each component of a union is a sequence */
+        public Seq[][] sequences;
+
+        /** if the union is a NonTerminal specified as Foo*=..., this is true */
+        public boolean rep;
+
+        /** if the union is a NonTerminal specified as Foo* /ws=..., then this is "ws" */
+        public String  sep = null;
+
+        public UnionNode(Seq seq) { this(new Seq[][] { new Seq[] { seq } }); }
+        public UnionNode(Seq[][] sequences) { this(sequences, false, null); }
+        public UnionNode(Seq[][] sequences, boolean rep, String sep) {
+            this.sequences = sequences;
+            this.rep = rep;
+            this.sep = sep;
+        }
+        public String getFieldName() { return null; }
+        public boolean isLifted() { return false; }
+        public boolean isDropped(Context cx) {
+            for(Seq[] seqs : sequences)
+                for(Seq seq : seqs)
+                    if (!seq.isDropped(cx))
+                        return false;
+            return true;
+        }
+        public Atom toAtom(Context cx) {
+            Atom ret = null;
+            for(Seq[] ss : sequences)
+                for(Seq s : ss)
+                    ret = ret==null ? s.toAtom(cx) : (Atom)ret.union(s.toAtom(cx));
+            return ret;
+        }
+
+        public Element build(Context cx, NonTerminalNode cnt, boolean dropall) {
+            return buildIntoPreallocatedUnion(cx, cnt, dropall, new Union(null, false)); }
+        public Element buildIntoPreallocatedUnion(Context cx, NonTerminalNode cnt, boolean dropall, Union u) {
+            Union urep = null;
+            if (rep) {
+                urep = new Union(null, false);
+                urep.add(Sequence.create(cnt.name, new Element[0]));
+                urep.add(sep==null
+                         ? Sequence.create(new Element[] { u }, 0)
+                         : Sequence.create(new Element[] { cx.get(sep), u }, 1));
+            }
+            HashSet<Sequence> bad2 = new HashSet<Sequence>();
+            for(int i=0; i<sequences.length; i++) {
+                Seq[] group = sequences[i];
+                Union u2 = new Union(null, false);
+                if (sequences.length==1) u2 = u;
+                for(int j=0; j<group.length; j++)
+                    if (!rep)
+                        group[j].build(cx, u2, cnt, dropall);
+                    else {
+                        Union u3 = new Union(null, false);
+                        group[j].build(cx, u3, cnt, dropall);
+                        Sequence s = Sequence.create(cnt.name,
+                                                     new Element[] { u3, urep },
+                                                     new boolean[] { false, false },
+                                                     new boolean[] { false, true});
+                        u2.add(s);
+                    }
+                if (sequences.length==1) break;
+                Sequence seq = Sequence.create(u2);
+                for(Sequence s : bad2) seq = seq.andnot(s);
+                u.add(seq);
+                bad2.add(Sequence.create(u2));
+            }
+            return u;
+        }
+    }
+
+    /** reference to a NonTerminal by name */
     private class ReferenceNode extends ElementNode {
         public String nonTerminal;
         public boolean parenthesized;
@@ -427,7 +455,7 @@ public class GrammarAST {
             return ret;
         }
         public Atom toAtom(Context cx) {
-            ElementNode ret = cx.grammar.get(nonTerminal);
+            ElementNode ret = cx.grammar.get(nonTerminal).getElementNode();
             if (ret == null) throw new RuntimeException("unknown nonterminal \""+nonTerminal+"\"");
             return ret.toAtom(cx);
         }
@@ -439,6 +467,7 @@ public class GrammarAST {
         }
     }
 
+    /** a literal string */
     private class LiteralNode extends ElementNode {
         private String string;
         private final String thePrefix = prefix;
@@ -460,6 +489,7 @@ public class GrammarAST {
         public Element build(Context cx, NonTerminalNode cnt, boolean dropall) { return CharAtom.string(string); }
     }
 
+    /** an atom (usually a character class) */
     private class AtomNode extends ElementNode {
         char[][] ranges;
         public AtomNode() { this(new char[0][]); }
@@ -473,6 +503,7 @@ public class GrammarAST {
         }
     }
 
+    /** a repetition */
     private class RepeatNode extends ElementNode {
         public ElementNode e, sep;
         public final boolean zero, many, max;
@@ -499,6 +530,7 @@ public class GrammarAST {
         }
     }
 
+    /** helper class for syntactic constructs that wrap another construct */
     private abstract class ElementNodeWrapper extends ElementNode {
         protected ElementNode _e;
         public ElementNodeWrapper(ElementNode e) { this._e = e; }
@@ -507,11 +539,13 @@ public class GrammarAST {
         public Element build(Context cx, NonTerminalNode cnt, boolean dropall) { return _e.build(cx, cnt, dropall); }
     }
 
+    /** a backtick node indicating that, when building the AST, the node's children should be inserted here */
     private class BacktickNode extends ElementNodeWrapper {
         public BacktickNode(ElementNode e) { super(e); }
         public boolean isLifted() { return true; }
     }
 
+    /** negation */
     private class TildeNode extends ElementNodeWrapper {
         public TildeNode(ElementNode e) { super(e); }
         public Atom toAtom(Context cx) { return (Atom)((Topology<Character>)_e.toAtom(cx).complement()); }
@@ -523,6 +557,12 @@ public class GrammarAST {
         public boolean isDropped(Context cx) { return true; }
     }
 
+    /** provides a label on the fields of a Seq */
+    private class LabelNode extends ElementNodeWrapper {
+        public final String label;
+        public LabelNode(String label, ElementNode e) { super(e); this.label = label; }
+    }
+
     //////////////////////////////////////////////////////////////////////////////
 
     public class Context {
@@ -550,7 +590,7 @@ public class GrammarAST {
             } else {
                 ret = new Union(name, false);
                 map.put(name, ret);
-                nt.buildIntoPreallocatedUnion(this, nt, nt.isDropped(this), ret);
+                nt.getUnionNode().buildIntoPreallocatedUnion(this, nt, nt.isDropped(this), ret);
             }
             return ret;
         }