X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FSequence.java;h=a029274a0a01f7cbe48db426e645c1def564e64a;hp=e18f5efc5ca56271fa6e225e75e0bf07d7062cbd;hb=0620c2d97d6df986d74dbe13160afb1435096431;hpb=242a8711e98cbd3ed6d05271bf910fde38e9be9a diff --git a/src/edu/berkeley/sbp/Sequence.java b/src/edu/berkeley/sbp/Sequence.java index e18f5ef..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.*; @@ -7,79 +9,131 @@ import java.util.*; import java.lang.reflect.*; import java.lang.ref.*; -/** juxtaposition; zero or more adjacent Elements; can specify a rewriting */ -public abstract class Sequence extends Element implements Iterable { +/** juxtaposition; zero or more adjacent Elements; can specify a rewriting */ +public abstract class Sequence implements Iterable, SequenceOrElement { + + protected final Element[] elements; + + public boolean needed_or_hated = false; + + public HashMap canNeed = new HashMap(); + public HashMap canKill = new HashMap(); + + final HashSet hated = new HashSet(); + + final HashSet needs = new HashSet(); + final HashSet hates = new HashSet(); + + final Position firstp; + + Atom follow = null; // Static Constructors ////////////////////////////////////////////////////////////////////////////// - /** the empty sequence (matches the empty string) */ - public static final Sequence empty = new Sequence.Constant.Empty(); + abstract Sequence _clone(); + Sequence dup() { + Sequence ret = _clone(); + for(Sequence s : needs) { ret.needs.add(s); } + for(Sequence s : hates) { ret.hates.add(s); s.hated.add(ret); } + ret.follow = follow; + return ret; + } + + /** create an empty sequence (matches the empty string) */ + public static Sequence create() { return new Sequence.Constant.Empty(); } - /** after matching the sequence, do not add anything to the output tree */ - public static Sequence drop(Element[] e, HashSet and, HashSet not, boolean lame) { return new Constant.Drop(e, and, not, lame); } + /** create a sequence of one element */ + public static Sequence create(Element e) { return create(new Element[] { e }, 0); } - /** after matching the sequence, insert a constant into the output tree */ - public static Sequence constant(Element[] e, Object o, HashSet and, HashSet not) { return new Constant(e, o, and, not); } + /** 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); } - /** after matching the sequence, place the result of the idxth match in the output tree */ - public static Sequence singleton(Element[] e, int idx, HashSet and, HashSet not) { return new Singleton(e, idx, and, not); } + /** create a sequence which always evaluates to a constant result */ + public static Sequence create(Element[] e, Object result) { return new Constant(e, result); } /** - * after matching the sequence, create the specified output tree - * @param tag the tag for the output tree - * @param e the elements to match - * @param drops only elements of e whose corresponding boolean in drops is false will be included in the output tree + * create a sequence (general form) + * @param head the head of the output tree + * @param e the elements to match + * @param drop only elements of e whose corresponding boolean in drops + * is false 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 **/ - public static Sequence rewritingSequence(Object tag, Element[] e, boolean[] drops, HashSet and, HashSet not) { - return new RewritingSequence(tag, e, drops, and, not); } + 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 Element noFollow = null; - public final Topology noFollow() { return noFollow==null ? null : noFollow.toAtom(); } + /** return a new sequence identical to this one, but with a positive conjunct s */ + public Sequence and(Sequence s) { Sequence ret = dup(); ret.needs.add(s); s.needed_or_hated=true; return ret; } - Topology toAtom() { - if (elements.length!=1) throw new RuntimeException("cannot invoke toAtom() on a Sequence with " + elements.length + " elements: " + this); - return elements[0].toAtom(); - } + /** return a new sequence identical to this one, but with a negative conjunct s */ + public Sequence andnot(Sequence s) { Sequence ret = dup(); ret.hates.add(s); s.hated.add(ret); s.needed_or_hated=true; return ret; } - protected final Element[] elements; + /** return a new sequence identical to this one, but with a follow-set restricted to a */ + public Sequence followedBy(Atom a) { Sequence ret = dup(); ret.follow = a; return ret; } - final HashSet needs; - final HashSet hates; - boolean lame = false; + boolean hatesAny(Iterable it) { + if (hates.isEmpty()) return false; + for(Sequence s : it) if (hates.contains(s)) return true; + return false; + } + + Iterable needs() { return needs; } + Iterable hates() { return hates; } - final Position firstp; Position firstp() { return firstp; } public Iterator iterator() { return new ArrayIterator(elements); } - protected Sequence(Element[] elements, HashSet and, HashSet not) { - this.needs = and==null ? new HashSet() : and; - this.hates = not==null ? new HashSet() : not; - //for(Sequence s : needs) s.lame = true; - //for(Sequence s : hates) s.lame = true; + protected Sequence(Element[] elements) { this.elements = elements; this.firstp = new Position(0); } - void reachable(HashSet h) { firstp().reachable(h); } - - Forest epsilonForm() { return firstp().rewrite(null); } + // DO NOT MESS WITH THE FOLLOWING LINE!!! + private Forest.Many epsilonForm = null; + Forest epsilonForm(Input.Region loc) { + if (epsilonForm!=null) return epsilonForm; + epsilonForm = new Forest.Many(); + epsilonForm.merge(firstp().rewrite(loc, false)); + return epsilonForm; + } - protected abstract Forest postReduce(Token.Location loc, Forest[] args); + protected abstract Forest postReduce(Input.Region loc, Forest[] args, Position p); // Position ////////////////////////////////////////////////////////////////////////////// /** the imaginary position before or after an element of a sequence; corresponds to an "LR item" */ - public class Position { + 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; + } - void reachable(HashSet h) { - if (h.contains(this)) return; - h.add(this); - if (element() != null) element().reachable(h); + private Forest zero = null; + public Forest zero(Input.Region reg) { + if (zero != null) return zero; + if (pos > 0) throw new Error(); + return zero = rewrite(reg); } + final int pos; private final Position next; final Forest[] holder; @@ -91,11 +145,6 @@ public abstract class Sequence extends Element implements Iterable { } boolean isFirst() { return pos==0; } - boolean isRightNullable(Walk.Cache cache) { - if (isLast()) return true; - if (!element().possiblyEpsilon(cache)) return false; - return next().isRightNullable(cache); - } /** the element immediately after this Position, or null if this is the last Position */ public Element element() { return pos>=elements.length ? null : elements[pos]; } @@ -109,12 +158,18 @@ public abstract class Sequence extends Element implements Iterable { /** true iff this Position is the last one in the sequence */ public boolean isLast() { return next()==null; } - // Reduction ///////////////////////////////////////////////////////////////////////////////// + // Position ///////////////////////////////////////////////////////////////////////////////// - Forest rewrite(Token.Location loc) { - for(int i=pos; i ret = Sequence.this.postReduce(loc, holder); - for(int k=0; k Forest rewrite(Input.Region loc) { return rewrite(loc, true); } + private final Forest rewrite(Input.Region loc, boolean epsilonCheck) { + if (epsilonCheck && this==firstp()) return epsilonForm(loc); + for(int i=0; i ret = Sequence.this.postReduce(loc, holder, this); + //for(int k=0; k { for(Position p = Sequence.this.firstp(); p != null; p = p.next()) { ret.append(' '); if (p==this) ret.append(" | "); - if (p.element()!=null) ret.append(p.element().possiblyEpsilon(null) ? "["+p.element()+"]" : p.element()); + if (p.element()!=null) ret.append(p.element()); else ret.append(' '); } ret.append("}>"); return ret.toString(); } + private final int idx = master_position_idx++; + public int toInt() { return idx; } } - + private static int master_position_idx = 0; // toString ////////////////////////////////////////////////////////////////////////////// @@ -142,6 +199,18 @@ public abstract class Sequence extends Element implements Iterable { sb.append(elements[i].toString()); sb.append(' '); } + if (follow != null) { + sb.append("-> "); + sb.append(follow); + } + for(Sequence s : needs) { + sb.append("& "); + sb.append(s); + } + for(Sequence s : hates) { + sb.append("&~ "); + sb.append(s); + } return sb; } @@ -150,66 +219,90 @@ public abstract class Sequence extends Element implements Iterable { static class Constant extends Sequence { private final Object result; - public Constant(Element[] e, Object result, HashSet and, HashSet not) { super(e, and, not); this.result = result; } - public Forest postReduce(Token.Location loc, Forest[] args) { - return (Forest)Forest.leaf(loc, result, this); + public Constant(Element[] e, Object result) { super(e); this.result = result; } + Sequence _clone() { return new Constant(elements, result); } + public Forest postReduce(Input.Region loc, Forest[] args, Position p) { + return (Forest)Forest.create(loc, result, null, false); } static class Drop extends Constant { - public Drop(Element[] e, HashSet and, HashSet not, boolean lame) { - super(e, null, and, not); - this.lame = lame; - } + Sequence _clone() { return new Drop(elements); } + public Drop(Element[] e) { super(e, null); } } - static class Empty extends Sequence.Constant.Drop { public Empty() { super(new Element[] { }, null, null, false); } } + static class Empty extends Sequence.Constant.Drop { + Sequence _clone() { return new Empty(); } + public Empty() { super(new Element[] { }); } } } static class Singleton extends Sequence { private final int idx; - public Singleton(Element e, HashSet and, HashSet not) { this(new Element[] { e }, 0, and, not); } - public Singleton(Element[] e, int idx, HashSet and, HashSet not) { super(e, and, not); this.idx = idx; } - public Forest postReduce(Token.Location loc, Forest[] args) { return (Forest)Forest.singleton(loc, args[idx], this); } + public Singleton(Element e) { this(new Element[] { e }, 0); } + public Singleton(Element[] e, int idx) { super(e); this.idx = idx; } + public Forest postReduce(Input.Region loc, Forest[] args, Position p) { return args[idx]; } + Sequence _clone() { return new Singleton(elements,idx); } } static class Unwrap extends Sequence { private boolean[] drops; - public Unwrap(Element[] e, HashSet and, HashSet not) { super(e, and, not); this.drops = null; } - public Unwrap(Element[] e, boolean[] drops, HashSet and, HashSet not) { super(e, and, not); this.drops = drops; } - public Forest postReduce(Token.Location loc, Forest[] args) { - if (drops==null) return Forest.create(loc, null, args, this, true, false); + private final Object tag; + public Unwrap(Element[] e, Object tag) { super(e); this.drops = null; this.tag = tag; } + 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 Forest postReduce(Input.Region loc, Forest[] args, Position p) { + for(int i=0; i[] args2 = new Forest[count]; int j = 0; for(int i=0; i tagf; + public RegionRewritingSequence(Functor tagfunctor, Element[] e, boolean[] drops) { + super(null, e, drops); + this.tagf = tagfunctor; + } + public Forest postReduce(Input.Region loc, Forest[] args, Position p) { + this.tag = tagf.invoke(loc); + Forest ret = super.postReduce(loc, args, p); + this.tag = null; + return ret; } } static class RewritingSequence extends Sequence { - private final Object tag; + /*private*/public /*final*/ Object tag; private final boolean[] drops; private int count = 0; - public RewritingSequence(Object tag, Element[] e, HashSet and, HashSet not) { this(tag, e, null, and, not); } - public RewritingSequence(Object tag, Element[] e, boolean[] drops, HashSet and, HashSet not) { - super(e, and, not); + 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) { + super(e); this.tag = tag; this.drops = drops == null ? new boolean[e.length] : drops; for(int i=0; i Forest postReduce(Token.Location loc, Forest[] args) { + public Forest postReduce(Input.Region loc, Forest[] args, Position p) { Forest[] args2 = new Forest[count]; int j = 0; for(int i=0; i "); - sb.append(tag); return sb; } } + }