X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FSequence.java;h=6b615dcd4460f7ffa3a0133474120924e0947294;hp=83d9b6f16bd3dda24d8b662c430eb71dc1ea1775;hb=5d18f5606c9296e6b0c5749f05fc68f358ace2f6;hpb=f33c05adc5aa3dd324c5352cdbd6f4b55359acad

diff --git a/src/edu/berkeley/sbp/Sequence.java b/src/edu/berkeley/sbp/Sequence.java
index 83d9b6f..6b615dc 100644
--- a/src/edu/berkeley/sbp/Sequence.java
+++ b/src/edu/berkeley/sbp/Sequence.java
@@ -12,17 +12,28 @@ public abstract class Sequence extends Element implements Iterable<Element> {
 
     // Static Constructors //////////////////////////////////////////////////////////////////////////////
 
+    public Sequence and(Sequence s) { Sequence ret = dup(); ret.needs.add(s); s.needed.add(ret); return ret; }
+    public Sequence not(Sequence s) { Sequence ret = dup(); ret.hates.add(s); s.hated.add(ret); return ret; }
+    abstract Sequence _clone();
+    Sequence dup() {
+        Sequence ret = _clone();
+        for(Sequence s : needs) { ret.needs.add(s); s.needed.add(ret); }
+        for(Sequence s : hates) { ret.hates.add(s); s.hated.add(ret); }
+        ret.noFollow = noFollow;
+        return ret;
+    }
+
     /** the empty sequence (matches the empty string) */
     public static final Sequence empty = new Sequence.Constant.Empty();
 
     /** after matching the sequence, do not add anything to the output tree */
-    public static Sequence drop(Element[] e, HashSet<Sequence> and, HashSet<Sequence> not, boolean lame) { return new Constant.Drop(e, and, not, lame); }
+    public static Sequence drop(Element[] e, boolean lame) { return new Constant.Drop(e, lame); }
 
     /** after matching the sequence, insert a constant into the output tree */
-    public static Sequence constant(Element[] e, Object o, HashSet<Sequence> and, HashSet<Sequence> not) { return new Constant(e, o, and, not); }
+    public static Sequence constant(Element[] e, Object o) { return new Constant(e, o); }
 
     /** after matching the sequence, place the result of the <tt>idx</tt>th match in the output tree */
-    public static Sequence singleton(Element[] e, int idx, HashSet<Sequence> and, HashSet<Sequence> not) { return new Singleton(e, idx, and, not); }
+    public static Sequence singleton(Element[] e, int idx) { return new Singleton(e, idx); }
 
     /**
      *  after matching the sequence, create the specified output tree
@@ -30,55 +41,59 @@ public abstract class Sequence extends Element implements Iterable<Element> {
      *  @param e     the elements to match
      *  @param drops only elements of <tt>e</tt> whose corresponding <tt>boolean</tt> in <tt>drops</tt> is <i>false</i> will be included in the output tree
      **/
-    public static Sequence rewritingSequence(Object tag, Element[] e, boolean[] drops, HashSet<Sequence> and, HashSet<Sequence> not) {
-        return new RewritingSequence(tag, e, drops, and, not); }
+    public static Sequence rewritingSequence(Object tag, Element[] e, boolean[] drops) { return new RewritingSequence(tag, e, drops); }
 
     ////////////////////////////////////////////////////////////////////////////////
 
     public Element noFollow = null;
-    public final Topology noFollow() { return noFollow==null ? null : noFollow.toAtom(); }
+    public final Topology noFollow() { return noFollow==null ? null : Atom.toAtom(noFollow); }
 
     Topology toAtom() {
         if (elements.length!=1) throw new RuntimeException("cannot invoke toAtom() on a Sequence with " + elements.length + " elements: " + this);
-        return elements[0].toAtom();
+        return Atom.toAtom(elements[0]);
     }
 
     protected final Element[] elements;
 
-    final HashSet<Sequence> needs;
-    final HashSet<Sequence> hates;
-          boolean           lame  = false;
+    final HashSet<Sequence> needed = new HashSet<Sequence>();
+    final HashSet<Sequence> hated = new HashSet<Sequence>();
+    final HashSet<Sequence> needs = new HashSet<Sequence>();
+    final HashSet<Sequence> hates = new HashSet<Sequence>();
+    public boolean           lame  = false;
 
     final Position          firstp;
     Position firstp() { return firstp; }
 
     public Iterator<Element> iterator()    { return new ArrayIterator<Element>(elements); }
-    protected Sequence(Element[] elements, HashSet<Sequence> and, HashSet<Sequence> not) {
-        this.needs = and==null ? new HashSet<Sequence>() : and;
-        this.hates = not==null ? new HashSet<Sequence>() : not;
+    protected Sequence(Element[] elements) {
         this.elements = elements;
         this.firstp = new Position(0);
     }
 
     // DO NOT MESS WITH THE FOLLOWING LINE!!!
     private Forest.Ref epsilonForm = null;
-    private boolean eps = false;
     Forest epsilonForm() {
-        if (epsilonForm==null) {
-            epsilonForm = new Forest.Ref();
-            Forest fo = firstp().rewrite(null);
-            epsilonForm.merge(fo);
-        }
+        if (epsilonForm!=null) return epsilonForm;
+        epsilonForm = new Forest.Ref();
+        epsilonForm.merge(firstp().rewrite(null, false));
         return epsilonForm;
     }
 
-    protected abstract <T> Forest<T> postReduce(Token.Location loc, Forest<T>[] args);
+    protected abstract <T> Forest<T> postReduce(Input.Location loc, Forest<T>[] args);
 
 
     // Position //////////////////////////////////////////////////////////////////////////////
 
     /** the imaginary position before or after an element of a sequence; corresponds to an "LR item" */
-    public class Position {
+    public class Position implements IntegerMappable {
+
+        private Forest zero = null;
+        public Forest zero() {
+            if (zero != null) return zero;
+            if (pos > 0) throw new Error();
+            return zero = rewrite(null);
+        }
+
 
                 final int      pos;
         private final Position next;
@@ -91,11 +106,6 @@ public abstract class Sequence extends Element implements Iterable<Element> {
         }
 
         boolean isFirst() { return pos==0; }
-        boolean isRightNullable(Walk.Cache cache) {
-            if (isLast()) return true;
-            if (!element().possiblyEpsilon(cache)) return false;
-            return next().isRightNullable(cache);
-        }
 
         /** the element immediately after this Position, or null if this is the last Position */
         public Element  element() { return pos>=elements.length ? null : elements[pos]; }
@@ -109,11 +119,11 @@ public abstract class Sequence extends Element implements Iterable<Element> {
         /** true iff this Position is the last one in the sequence */
         public boolean isLast() { return next()==null; }
 
-        // Reduction /////////////////////////////////////////////////////////////////////////////////
+        // Position /////////////////////////////////////////////////////////////////////////////////
 
-        final <T> Forest<T> rewrite(Token.Location loc) {
-            if (this==firstp() && eps) return epsilonForm;
-            eps = true;
+        final <T> Forest<T> rewrite(Input.Location loc) { return rewrite(loc, true); }
+        private final <T> Forest<T> rewrite(Input.Location loc, boolean epsilonCheck) {
+            if (epsilonCheck && this==firstp()) return epsilonForm();
             for(int i=0; i<pos; i++) if (holder[i]==null) throw new Error("realbad " + i);
             for(int i=pos; i<elements.length; i++) {
                 if (holder[i]==null) holder[i] = elements[i].epsilonForm();
@@ -121,7 +131,6 @@ public abstract class Sequence extends Element implements Iterable<Element> {
             }
             Forest<T> ret = Sequence.this.postReduce(loc, holder);
             for(int k=0; k<pos; k++) holder[k] = null; // to help GC
-            if (this==firstp()) { if (epsilonForm==null) epsilonForm=new Forest.Ref(); epsilonForm.merge(ret); return epsilonForm; }
             return ret;
         }
 
@@ -131,14 +140,16 @@ public abstract class Sequence extends Element implements Iterable<Element> {
             for(Position p = Sequence.this.firstp(); p != null; p = p.next()) {
                 ret.append(' ');
                 if (p==this) ret.append(" | ");
-                if (p.element()!=null) ret.append(p.element().possiblyEpsilon(null) ? "["+p.element()+"]" : p.element());
+                if (p.element()!=null) ret.append(p.element());
                 else                   ret.append(' ');
             }
             ret.append("}>");
             return ret.toString();
         }
+        private final int idx = master_position_idx++;
+        public int toInt() { return idx; }
     }
-
+    private static int master_position_idx = 0;
 
     // toString //////////////////////////////////////////////////////////////////////////////
 
@@ -157,59 +168,66 @@ public abstract class Sequence extends Element implements Iterable<Element> {
 
     static class Constant extends Sequence {
         private final Object result;
-        public Constant(Element[] e, Object result, HashSet<Sequence> and, HashSet<Sequence> not) { super(e, and, not); this.result = result; }
-        public <T> Forest<T> postReduce(Token.Location loc, Forest<T>[] args) {
-            return (Forest<T>)Forest.leaf(loc, result, this);
+        public Constant(Element[] e, Object result) { super(e); this.result = result; }
+        Sequence _clone() { return new Constant(elements, result); }
+        public <T> Forest<T> postReduce(Input.Location loc, Forest<T>[] args) {
+            return (Forest<T>)Forest.leaf(loc, result);
         }
         static class Drop extends Constant {
-            public Drop(Element[] e, HashSet<Sequence> and, HashSet<Sequence> not, boolean lame) {
-                super(e, null, and, not);
+            Sequence _clone() { return new Drop(elements, lame); }
+            public Drop(Element[] e, boolean lame) {
+                super(e, null);
                 this.lame = lame;
             }
         }
-        static class Empty extends Sequence.Constant.Drop { public Empty() { super(new Element[] { }, null, null, false); } }
+        static class Empty extends Sequence.Constant.Drop {
+            Sequence _clone() { return new Empty(); }
+            public Empty() { super(new Element[] { }, false); } }
     }
 
     static class Singleton extends Sequence {
         private final int idx;
-        public Singleton(Element e, HashSet<Sequence> and, HashSet<Sequence> not) { this(new Element[] { e }, 0, and, not); }
-        public Singleton(Element[] e, int idx, HashSet<Sequence> and, HashSet<Sequence> not) { super(e, and, not); this.idx = idx; }
-        public <T> Forest<T> postReduce(Token.Location loc, Forest<T>[] args) { return (Forest<T>)Forest.singleton(loc, args[idx], this); }
+        public Singleton(Element e) { this(new Element[] { e }, 0); }
+        public Singleton(Element[] e, int idx) { super(e); this.idx = idx; }
+        public <T> Forest<T> postReduce(Input.Location loc, Forest<T>[] args) { return (Forest<T>)Forest.singleton(loc, args[idx]); }
+        Sequence _clone() { return new Singleton(elements,idx); }
     }
 
-    static class Unwrap extends Sequence {
+    public static class Unwrap extends Sequence {
         private boolean[] drops;
-        public Unwrap(Element[] e, HashSet<Sequence> and, HashSet<Sequence> not)                  { super(e, and, not); this.drops = null; }
-        public Unwrap(Element[] e, boolean[] drops, HashSet<Sequence> and, HashSet<Sequence> not) { super(e, and, not); this.drops = drops; }
-        public <T> Forest<T> postReduce(Token.Location loc, Forest<T>[] args) {
+        public Unwrap(Element[] e)                  { super(e); this.drops = null; }
+        public Unwrap(Element[] e, boolean[] drops) { super(e); this.drops = drops; }
+        Sequence _clone() { return new Unwrap(elements, drops); }
+        public <T> Forest<T> postReduce(Input.Location loc, Forest<T>[] args) {
             for(int i=0; i<args.length; i++) if (args[i]==null) throw new Error();
-            if (drops==null) return Forest.create(loc, null, args, this, true, false);
+            if (drops==null) return Forest.create(loc, null, args, true, false);
             int count = 0;
             for(int i=0; i<drops.length; i++) if (!drops[i]) count++;
             Forest<T>[] args2 = new Forest[count];
             int j = 0;
             for(int i=0; i<args.length; i++) if (!drops[i]) args2[j++] = args[i];
-            return Forest.create(loc, null, args2, this, true, false);            
+            return Forest.create(loc, null, args2, true, false);            
         }
     }
 
     static class RewritingSequence extends Sequence {
-        private final Object tag;
+        /*private*/public final Object tag;
         private final boolean[] drops;
         private int count = 0;
-        public RewritingSequence(Object tag, Element[] e, HashSet<Sequence> and, HashSet<Sequence> not) { this(tag, e, null, and, not); }
-        public RewritingSequence(Object tag, Element[] e, boolean[] drops, HashSet<Sequence> and, HashSet<Sequence> not) {
-            super(e, and, not);
+        Sequence _clone() { return new RewritingSequence(tag, elements, drops); }
+        public RewritingSequence(Object tag, Element[] e) { this(tag, e, null); }
+        public RewritingSequence(Object tag, Element[] e, boolean[] drops) {
+            super(e);
             this.tag = tag;
             this.drops = drops == null ? new boolean[e.length] : drops;
             for(int i=0; i<this.drops.length; i++) if (!this.drops[i]) count++;
         }
-        public <T> Forest<T> postReduce(Token.Location loc, Forest<T>[] args) {
+        public <T> Forest<T> postReduce(Input.Location loc, Forest<T>[] args) {
             Forest<T>[] args2 = new Forest[count];
             int j = 0;
             for(int i=0; i<args.length; i++) if (!drops[i]) args2[j++] = args[i];
             //System.out.println("reduce \""+tag+"\"");
-            return Forest.create(loc, (T)tag, args2, this, false, false);
+            return Forest.create(loc, (T)tag, args2, false, false);
         }
         public StringBuffer toString(StringBuffer sb, boolean spacing) {
             int len = sb.length();