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 8d6709d..bb0ba48 100644 (file)
--- a/src/edu/berkeley/sbp/Sequence.java
+++ b/src/edu/berkeley/sbp/Sequence.java
@@ -33,18 +33,17 @@ public abstract class Sequence extends Element implements Iterable<Element> {
     }
 
     /** the empty sequence (matches the empty string) */
-    static final Sequence empty = new Sequence.Constant.Empty();
-    public static Sequence empty() { return empty; }
+    public static Sequence newEmptySequence() { return new Sequence.Constant.Empty(); }
 
     /** after matching the sequence, do not add anything to the output tree */
-    public static Sequence drop(Element[] e) { return new Constant.Drop(e); }
+    public static Sequence newDropSequence(Element[] e) { return new Constant.Drop(e); }
 
     /** after matching the sequence, insert a constant into the output tree */
-    public static Sequence constant(Element[] e, Object o) { return new Constant(e, o); }
+    public static Sequence newConstantSequence(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) { return new Singleton(e, idx); }
-    public static Sequence singleton(Element e) { return singleton(new Element[] { e }, 0); }
+    public static Sequence newSingletonSequence(Element[] e, int idx) { return new Singleton(e, idx); }
+    public static Sequence newSingletonSequence(Element e) { return newSingletonSequence(new Element[] { e }, 0); }
 
     /**
      *  after matching the sequence, create the specified output tree
@@ -53,16 +52,20 @@ public abstract class Sequence extends Element implements Iterable<Element> {
      *  @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) {
+    public static Sequence newRewritingSequence(Object tag, Element[] e, boolean[] drops) {
         return new RewritingSequence(tag, e, drops); }
 
-    public static Sequence regionRewritingSequence(Functor<Input.Region,Object> tagfunctor, Element[] e, boolean[] drops) {
-        return new RegionRewritingSequence(tagfunctor, e, drops); }
+    public static Sequence newUnwrapSequence(Element[] e, Object tag, boolean[] drops) { return new Unwrap(e, tag, drops); }
 
     ////////////////////////////////////////////////////////////////////////////////
 
+    /** return a new sequence identical to this one, but with a positive conjunct <tt>s</tt> */
     public Sequence and(Sequence s) { Sequence ret = dup(); ret.needs.add(s); return ret; }
+
+    /** return a new sequence identical to this one, but with a negative conjunct <tt>s</tt> */
     public Sequence not(Sequence s) { Sequence ret = dup(); ret.hates.add(s); s.hated.add(ret); return ret; }
+
+    /** return a new sequence identical to this one, but with a follow-set restricted to <tt>a</tt> */
     public Sequence followedBy(Atom a) { Sequence ret = dup(); ret.follow = a; return ret; }
 
     Iterable<Sequence> needs() { return needs; }
@@ -200,7 +203,6 @@ public abstract class Sequence extends Element implements Iterable<Element> {
         Sequence _clone() { return new Singleton(elements,idx); }
     }
 
-    public static Sequence unwrap(Element[] e, Object tag, boolean[] drops) { return new Unwrap(e, tag, drops); }
     static class Unwrap extends Sequence {
         private boolean[] drops;
         private final Object tag;