X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FSequence.java;h=79854c64b6b106ad2d4e972781a575ee552192ba;hb=6e0ac72335464f3151c0621cc02433800d13c18a;hp=c41be4ff9d62da6ba0537477b13c3db22aaed42d;hpb=2afdfe14e78fa0597186614937c679a09d74ecdf;p=sbp.git

diff --git a/src/edu/berkeley/sbp/Sequence.java b/src/edu/berkeley/sbp/Sequence.java
index c41be4f..79854c6 100644
--- a/src/edu/berkeley/sbp/Sequence.java
+++ b/src/edu/berkeley/sbp/Sequence.java
@@ -1,4 +1,4 @@
-// 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.util.*;
@@ -24,20 +24,44 @@ public abstract class Sequence implements Iterable<Element>, SequenceOrElement {
     HashMap<Sequence,Boolean> canNeed = new HashMap<Sequence,Boolean>();
     HashMap<Sequence,Boolean> canKill = new HashMap<Sequence,Boolean>();
 
-    final Position          firstp;
+    final Position firstp;
 
     Atom follow = null;
 
+    private static int global_sernum = 0;
+    private int sernum = global_sernum++;
+    int[] needs_int() {
+        int[] ret = new int[needs.size()];
+        int i = 0;
+        for(Sequence s : needs) ret[i++] = s.sernum;
+        return ret;
+    }
+    int[] hates_int() {
+        int[] ret = new int[hates.size()];
+        int i = 0;
+        for(Sequence s : hates) ret[i++] = s.sernum;
+        return ret;
+    }
+
+
     // Static Constructors //////////////////////////////////////////////////////////////////////////////
 
     /** create a sequence of one element */
     public static Sequence create(Element e) { return create(new Element[] { e }, 0); }
 
     /** create a sequence which drops the result of all but one of its element */
-    public static Sequence create(Element[] e, int which) { return new Singleton(e, which); }
+    public static Sequence create(Element[] e, int which) {
+        return new Singleton(e, which); }
 
     /** create a sequence which always evaluates to a constant result  */
-    public static Sequence create(Element[] e, Object result) { return new Constant(e, result); }
+    public static Sequence create(Object result, Element[] e) {
+        return new RewritingSequence(result, e, trues(e.length)); }
+
+    private static boolean[] trues(int length) {
+        boolean[] ret = new boolean[length];
+        for(int i=0; i<ret.length; i++) ret[i] = true;
+        return ret;
+    }
 
     /**
      *  create a sequence (general form)
@@ -45,19 +69,13 @@ public abstract class Sequence implements Iterable<Element>, SequenceOrElement {
      *  @param e      the elements to match
      *  @param drop   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
-     *  @param foster if true, all children of the last child (ie
-     *                grandchildren) are promoted to children of this
-     *                node; this is very useful for matching repetitions
+     *  @param lifts  which (if any) child trees to lift
      **/
-    public static Sequence create(Object head, Element[] e, boolean[] drop, boolean foster) {
-        return foster
-            ? new Unwrap(e, head, drop)
-            : new RewritingSequence(head, e, drop);
-    }
-    public static Sequence createLeft(Object head, Element[] e, boolean[] drop, boolean foster) {
-        return foster
-            ? new UnwrapLeft(e, head, drop)
-            : new RewritingSequence(head, e, drop);
+    public static Sequence create(Object head, Element[] e, boolean[] drop) {
+        return create(head, e, drop, new boolean[e.length]); }
+    public static Sequence create(Object head, Element[] e, boolean[] drop, boolean[] lifts) {
+        if (lifts==null) lifts = new boolean[e.length];
+        return new RewritingSequence(head, e, drop, lifts);
     }
 
     /** return a new sequence identical to this one, but with a positive conjunct <tt>s</tt> */
@@ -116,32 +134,59 @@ public abstract class Sequence implements Iterable<Element>, SequenceOrElement {
 
     // Position //////////////////////////////////////////////////////////////////////////////
 
-    /** the imaginary position before or after an element of a sequence; corresponds to an "LR item" */
-    class Position implements IntegerMappable {
+    static abstract class Pos implements IntegerMappable, Comparable<Pos>, Serializable {
+        final Forest[] holder;
+        Pos(int len) { this.holder = new Forest[len]; }
 
-        public int ord = -1;
+        public abstract int   provides();
+        public abstract int[] needs();
+        public abstract int[] hates();
+        public abstract boolean            owner_needed_or_hated();
 
-        private Forest zero = null;
+        public abstract int numPops();
+        public abstract <T> Forest<T> rewrite(Input.Region loc, Grammar cache);
+    }
+
+    /** the imaginary position before or after an element of a sequence; corresponds to an "LR item" */
+    class Position extends Pos implements IntegerMappable {
         /*
-        public Forest zero(Input.Region reg) {
-            if (zero != null) return zero;
-            if (pos > 0) throw new RuntimeException("Position.zero(): pos>0");
-            return zero = rewrite(reg);
+        public Pos getPos() {
+            return new DumbPos(elements.length, provides(), needs(), hates(), owner_needed_or_hated(), numPops(), 
+                public int   provides();
+                public int[] needs();
+                public int[] hates();
+                public boolean            owner_needed_or_hated();
+                public int numPops();
+                public <T> Forest<T> rewrite(Input.Region loc, Grammar cache)
+            };
         }
         */
+        public int ord = -1;
+        public int ord()     { return ord; }
+        public int numPops() { return pos; }
+
                 final int      pos;
         private final Position next;
         private final Position prev;
-                final Forest[] holder;
+
+        public int     provides() { return owner().sernum; }
+        public int[]   needs() { return owner().needs_int(); }
+        public int[]   hates() { return owner().hates_int(); }
+        public boolean owner_needed_or_hated() { return owner().needed_or_hated; }
         
         private Position(int pos, Position prev) {
+            super(elements.length);
             this.pos      = pos;
             this.next     = pos==elements.length ? null : new Position(pos+1, this);
-            this.holder   = new Forest[elements.length];
             this.prev     = prev;
         }
 
+        public int compareTo(Pos p) {
+            return ord - ((Position)p).ord;
+        }
+
         boolean isFirst() { return pos==0; }
+        public int pos() { return pos; }
 
         /** the element immediately after this Position, or null if this is the last Position */
         public Element  element() { return pos>=elements.length ? null : elements[pos]; }
@@ -159,7 +204,7 @@ public abstract class Sequence implements Iterable<Element>, SequenceOrElement {
 
         // Position /////////////////////////////////////////////////////////////////////////////////
 
-        final <T> Forest<T> rewrite(Input.Region loc, Grammar cache) {
+        public final <T> Forest<T> rewrite(Input.Region loc, Grammar cache) {
             if (this==firstp()) epsilonForm(loc, cache);
             for(int i=0; i<pos; i++) if (holder[i]==null) throw new Error("realbad " + i);
             for(int i=pos; i<elements.length; i++) {
@@ -186,6 +231,7 @@ public abstract class Sequence implements Iterable<Element>, SequenceOrElement {
     }
     private static int master_position_idx = 0;
 
+
     // toString //////////////////////////////////////////////////////////////////////////////
 
     public String toString() { return toString(new StringBuffer(), false).toString(); }
@@ -213,22 +259,6 @@ public abstract class Sequence implements Iterable<Element>, SequenceOrElement {
 
     // Specialized Subclasses //////////////////////////////////////////////////////////////////////////////
 
-    static class Constant extends Sequence {
-        private final Object result;
-        public Constant(Element[] e, Object result) {
-            super(e);
-            if (result==null) throw new Error("constant sequences may not have result==null");
-            this.result = result;
-        }
-        Sequence _clone() { return new Constant(elements, result); }
-        public <T> Forest<T> postReduce(Input.Region loc, Forest<T>[] args, Position p) {
-            return (Forest<T>)Forest.create(loc, result, null, false);
-        }
-        Forest epsilonForm(Input.Region loc, Grammar cache) {
-            return Forest.create(loc, result, null, false);
-        }
-    }
-
     static class Singleton extends Sequence {
         private final int idx;
         public Singleton(Element e) { this(new Element[] { e }, 0); }
@@ -240,66 +270,31 @@ public abstract class Sequence implements Iterable<Element>, SequenceOrElement {
         }
     }
 
-    static class Unwrap extends Sequence {
-        private boolean[] drops;
-        private final Object tag;
-        public Unwrap(Element[] e, Object tag)                  { this(e, tag, null); }
-        public Unwrap(Element[] e, Object tag, boolean[] drops) { super(e); this.drops = drops; this.tag = tag; }
-        Sequence _clone() { return new Unwrap(elements, tag, drops); }
-        public <T> Forest<T> postReduce(Input.Region loc, Forest<T>[] args, Position p) {
-            for(int i=0; i<args.length; i++) if (args[i]==null) throw new Error();
-            if (drops==null) return Forest.create(loc, (T)tag, args, true);
-            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, (T)tag, args2, true);
-        }
-        Forest epsilonForm(Input.Region loc, Grammar cache) {
-            return Forest.create(loc, tag, new Forest[0], false);
-        }
-    }
-
-    static class UnwrapLeft extends Sequence {
-        private boolean[] drops;
-        private final Object tag;
-        public UnwrapLeft(Element[] e, Object tag)                  { this(e, tag, null); }
-        public UnwrapLeft(Element[] e, Object tag, boolean[] drops) { super(e); this.drops = drops; this.tag = tag; }
-        Sequence _clone() { return new UnwrapLeft(elements, tag, drops); }
-        public <T> Forest<T> postReduce(Input.Region loc, Forest<T>[] args, Position p) {
-            for(int i=0; i<args.length; i++) if (args[i]==null) throw new Error();
-            if (drops==null) return Forest.create(loc, (T)tag, args, false, true);
-            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, (T)tag, args2, false, true);
-        }
-        Forest epsilonForm(Input.Region loc, Grammar cache) {
-            return Forest.create(loc, tag, new Forest[0], false);
-        }
-    }
-
     static class RewritingSequence extends Sequence {
-        private Object tag;
+        private final Object    tag;
         private final boolean[] drops;
-        private int count = 0;
+        private final boolean[] lifts;
         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) {
+        public RewritingSequence(Object tag, Element[] e, boolean[] drops) { this(tag, e, drops, new boolean[e.length]); }
+        public RewritingSequence(Object tag, Element[] e, boolean[] drops, boolean[] lifts) {
             super(e);
             if (tag==null) throw new Error();
             this.tag = tag;
             this.drops = drops == null ? new boolean[e.length] : drops;
+            int count = 0;
             for(int i=0; i<this.drops.length; i++) if (!this.drops[i]) count++;
+            this.lifts = new boolean[count];
+            int j = 0;
+            for(int i=0; i<this.drops.length; i++)
+                if (!this.drops[i])
+                    this.lifts[j++] = lifts[i];
         }
         public <T> Forest<T> postReduce(Input.Region loc, Forest<T>[] args, Position p) {
-            Forest<T>[] args2 = new Forest[count];
+            Forest<T>[] args2 = new Forest[lifts.length];
             int j = 0;
             for(int i=0; i<args.length; i++) if (!drops[i]) args2[j++] = args[i];
-            return Forest.create(loc, (T)tag, args2, false);
+            return Forest.create(loc, (T)tag, args2, lifts);
         }
         public StringBuffer toString(StringBuffer sb, boolean spacing) {
             int len = sb.length();
@@ -311,8 +306,7 @@ public abstract class Sequence implements Iterable<Element>, SequenceOrElement {
             return sb;
         }
         Forest epsilonForm(Input.Region loc, Grammar cache) {
-            return Forest.create(loc, tag, new Forest[0], false);
+            return Forest.create(loc, tag, new Forest[0], lifts);
         }
     }
-
 }