rename Node->StateNode

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

diff --git a/src/edu/berkeley/sbp/Reduction.java b/src/edu/berkeley/sbp/Reduction.java
index e845764..0266782 100644 (file)
--- a/src/edu/berkeley/sbp/Reduction.java
+++ b/src/edu/berkeley/sbp/Reduction.java
@@ -1,92 +1,51 @@
-// Copyright 2006 all rights reserved; see LICENSE file for BSD-style license
+// Copyright 2006-2007 all rights reserved; see LICENSE file for BSD-style license
 
 package edu.berkeley.sbp;
-import edu.berkeley.sbp.*;
-import edu.berkeley.sbp.util.*;
-import edu.berkeley.sbp.Parser.Table.*;
-import edu.berkeley.sbp.Sequence.Position;
-import java.io.*;
-import java.util.*;
-import java.lang.reflect.*;
+import edu.berkeley.sbp.Sequence.Pos;
+import edu.berkeley.sbp.Sequence.Pos;
 
 final class Reduction implements Comparable<Reduction> {
 
-    public Position position;
-    public GSS.Phase phase;
-    public Forest result;
-    public Node node;
-    boolean done = false;
+    private Pos reduction;
+    private GSS.Phase phase;
+    private Forest forest;
+    private StateNode pred;
     
-    public Reduction(Node node, Position position, Forest result, GSS.Phase target) {
-        this.position = position;
-        this.result = result;
+    public Reduction(StateNode pred, Pos reduction, Forest forest, GSS.Phase target) {
+        this.reduction = reduction;
+        this.forest = forest;
         this.phase = target;
-        this.node = node;
+        this.pred = pred;
+        target.addReduction(this);
     }
 
-    public void perform() {
-        if (done) return;
-        done = true;
-        node.finish(position, result, phase);
-    }
-
-    public String toString() { return position+""; }
-
     public int compareTo(Reduction r) {
-        int ret = compareTo0(r);
-        if (ret == 0) {
-            Walk.Cache cache = node.state().cache();
-            if (canKill(cache, position, r.position) && canKill(cache, r.position, position)) throw new Error();
-            if      (canKill(cache, position,   r.position)) ret =  1;
-            else if (canKill(cache, r.position, position)) ret = -1;
-            if      (canNeed(cache, position,   r.position)) ret =  1;
-            else if (canNeed(cache, r.position, position)) ret = -1;
-        }
-        return -1 * ret;
-    }
-
-    private boolean isRightNullable(Walk.Cache c, Position p) {
-        if (p.isLast()) return true;
-        if (!c.possiblyEpsilon(p.element())) return false;
-        return isRightNullable(c, p.next());
-    }
-
-    public boolean canKill(Walk.Cache cache, Position mep, Position himp) {
-        if (!isRightNullable(cache, mep))  return false;
-        if (!isRightNullable(cache, himp)) return false;
-        Sequence me  = mep.owner();
-        Sequence him = himp.owner();
-        for(Sequence killer : him.hates()) {
-            HashSet<Sequence> eq2 = new Walk.EquivalentTo(killer, cache).walk();
-            if (eq2.contains(me)) return true;
+        if (pred.phase()!=null || r.pred.phase()!=null) {
+            if (pred.phase()==null) return 1;
+            if (r.pred.phase()==null) return -1;
+            if (pred.phase().pos < r.pred.phase().pos) return 1;
+            if (pred.phase().pos > r.pred.phase().pos) return -1;
         }
-        return false;
+        /*
+        int master = Parser.mastercache.comparePositions(reduction(), r.reduction());
+        if (master != 0 && master != signum(reduction.ord() - r.reduction.ord()))
+            throw new Error("master="+master+" and a="+reduction.ord()+" and b="+r.reduction.ord()+"\n"+reduction+"\n"+r.reduction);
+        */
+        return reduction.compareTo(r.reduction);
     }
 
-    public static final int LESS_THAN = -1;
-    public static final int EQUAL_TO = 0;
-    public static final int GREATER_THAN = 1;
-
-    public int compareTo0(Reduction n) {
-        if (targetPhase()==null && n.targetPhase()==null) return EQUAL_TO;
-        if (targetPhase()==null) return LESS_THAN;
-        if (n.targetPhase()==null) return GREATER_THAN;
-        if (targetPhase().pos < n.targetPhase().pos) return LESS_THAN;
-        if (targetPhase().pos > n.targetPhase().pos) return GREATER_THAN;
-        return 0;
+    private int signum(int x) {
+        if (x==0) return 0;
+        if (x<0) return -1;
+        return 1;
     }
-    public int pos() { return targetPhase()==null ? 0 : targetPhase().pos; }
-    public GSS.Phase targetPhase() { return node.phase(); }
 
-    public boolean canNeed(Walk.Cache cache, Position mep, Position himp) {
-        if (!isRightNullable(cache, mep))  return false;
-        if (!isRightNullable(cache, himp)) return false;
-        Sequence me  = mep.owner();
-        Sequence him = himp.owner();
-        for(Sequence needer : him.needs()) {
-            HashSet<Sequence> eq2 = new Walk.EquivalentTo(needer, cache).walk();
-            if (eq2.contains(me)) return true;
-        }
-        return false;
+    public void perform() {
+        if (reduction==null) return;
+        phase.newNodeFromReduction(forest, reduction, pred);
     }
+    public GSS.Phase predPhase() { return pred.phase(); }
+    public Pos reduction() { return reduction; }
+    public GSS.Phase targetPhase() { return phase; }
+    public String toString() { return (pred.phase()==null ? 0 : pred.phase().pos) + ":"+reduction; }
 }