checkpoint

[sbp.git] / src / edu / berkeley / sbp / Sequence.java

diff --git a/src/edu/berkeley/sbp/Sequence.java b/src/edu/berkeley/sbp/Sequence.java
index 68e311e..f21bb80 100644 (file)
--- a/src/edu/berkeley/sbp/Sequence.java
+++ b/src/edu/berkeley/sbp/Sequence.java
@@ -22,13 +22,13 @@ public abstract class Sequence extends Element implements Iterable<Element> {
     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, null, null, 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, null, null); }
 
     /** 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, null, null); }
 
     /**
      *  after matching the sequence, create the specified output tree
@@ -36,8 +36,7 @@ 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, null, null); }
 
     ////////////////////////////////////////////////////////////////////////////////
 
@@ -53,25 +52,20 @@ public abstract class Sequence extends Element implements Iterable<Element> {
 
     protected final Element[] elements;
 
-          HashSet<Sequence> needed;
-          HashSet<Sequence> hated;
-    final HashSet<Sequence> needs;
-    final HashSet<Sequence> hates;
+    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) { this(elements, null, null); }
     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;
-        if (this.needs != null)
-            for(Sequence s : this.needs)
-                (s.needed==null?(s.needed=new HashSet<Sequence>()):s.needed).add(this);
-        if (this.hates != null)
-            for(Sequence s : this.hates)
-                (s.hated==null?(s.hated=new HashSet<Sequence>()):s.hated).add(this);
+        if (and!=null) for(Sequence s : and) { needs.add(s); s.needed.add(this); }
+        if (not!=null) for(Sequence s : not) { hates.add(s); s.hated.add(this); }
         this.elements = elements;
         this.firstp = new Position(0);
     }
@@ -205,10 +199,10 @@ public abstract class Sequence extends Element implements Iterable<Element> {
 
     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 Sequence and(Sequence s) { Sequence ret = new Unwrap(elements, drops, needs, hates); ret.needs(s); return ret; }
-        public Sequence not(Sequence s) { Sequence ret = new Unwrap(elements, drops, needs, hates); ret.hates(s); return ret; }
+        public Unwrap(Element[] e)                  { super(e); this.drops = null; }
+        public Unwrap(Element[] e, boolean[] drops) { super(e); this.drops = drops; }
+        public Sequence and(Sequence s) { Sequence ret = new Unwrap(elements, drops); ret.needs(s); return ret; }
+        public Sequence not(Sequence s) { Sequence ret = new Unwrap(elements, drops); ret.hates(s); return ret; }
         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, true, false);