X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FSequence.java;h=a029274a0a01f7cbe48db426e645c1def564e64a;hp=84a2dc6768d6edeab19b06432bb580fc4c634eee;hb=0620c2d97d6df986d74dbe13160afb1435096431;hpb=8a5250c184672495fae152e096b2e800749cd0db

diff --git a/src/edu/berkeley/sbp/Sequence.java b/src/edu/berkeley/sbp/Sequence.java
index 84a2dc6..a029274 100644
--- a/src/edu/berkeley/sbp/Sequence.java
+++ b/src/edu/berkeley/sbp/Sequence.java
@@ -1,3 +1,5 @@
+// Copyright 2006 all rights reserved; see LICENSE file for BSD-style license
+
 package edu.berkeley.sbp;
 import edu.berkeley.sbp.util.*;
 import edu.berkeley.sbp.*;
@@ -12,7 +14,12 @@ public abstract class Sequence implements Iterable<Element>, SequenceOrElement {
 
     protected final Element[] elements;
 
-    final HashSet<Sequence> hated  = new HashSet<Sequence>();
+    public boolean needed_or_hated = false;
+
+    public HashMap<Sequence,Boolean> canNeed = new HashMap<Sequence,Boolean>();
+    public HashMap<Sequence,Boolean> canKill = new HashMap<Sequence,Boolean>();
+
+    final HashSet<Sequence> hated   = new HashSet<Sequence>();
 
     final HashSet<Sequence> needs  = new HashSet<Sequence>();
     final HashSet<Sequence> hates  = new HashSet<Sequence>();
@@ -63,14 +70,20 @@ public abstract class Sequence implements Iterable<Element>, SequenceOrElement {
     ////////////////////////////////////////////////////////////////////////////////
 
     /** 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; }
+    public Sequence and(Sequence s) { Sequence ret = dup(); ret.needs.add(s); s.needed_or_hated=true; return ret; }
 
     /** return a new sequence identical to this one, but with a negative conjunct <tt>s</tt> */
-    public Sequence andnot(Sequence s) { Sequence ret = dup(); ret.hates.add(s); s.hated.add(ret); return ret; }
+    public Sequence andnot(Sequence s) { Sequence ret = dup(); ret.hates.add(s); s.hated.add(ret); s.needed_or_hated=true; 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; }
 
+    boolean hatesAny(Iterable<Sequence> it) {
+        if (hates.isEmpty()) return false;
+        for(Sequence s : it) if (hates.contains(s)) return true;
+        return false;
+    }
+
     Iterable<Sequence> needs() { return needs; }
     Iterable<Sequence> hates() { return hates; }
 
@@ -99,6 +112,20 @@ public abstract class Sequence implements Iterable<Element>, SequenceOrElement {
     /** the imaginary position before or after an element of a sequence; corresponds to an "LR item" */
     class Position implements IntegerMappable {
 
+        public int ord = -1;
+        public int compareTo(Position p, Walk.Cache cache) {
+            Position position = this;
+            Position rposition = p;
+            int ret = 0;
+            if (Reduction.canKill(cache, position, rposition) &&
+                Reduction.canKill(cache, rposition, position)) throw new Error();
+            if      (Reduction.canKill(cache, position,   rposition)) ret =  1;
+            else if (Reduction.canKill(cache, rposition, position)) ret = -1;
+            if      (Reduction.canNeed(cache, position,   rposition)) ret =  1;
+            else if (Reduction.canNeed(cache, rposition, position)) ret = -1;
+            return ret;
+        }
+
         private Forest zero = null;
         public Forest zero(Input.Region reg) {
             if (zero != null) return zero;