X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FSequence.java;h=2c36c8db00c2dd2917eaf25e8e7e3e072a7f4b31;hp=6b615dcd4460f7ffa3a0133474120924e0947294;hb=a4cd33f348d3802ed746e517c23205958a4ceeb4;hpb=5d18f5606c9296e6b0c5749f05fc68f358ace2f6 diff --git a/src/edu/berkeley/sbp/Sequence.java b/src/edu/berkeley/sbp/Sequence.java index 6b615dc..2c36c8d 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.*; @@ -7,62 +9,91 @@ 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 { - // Static Constructors ////////////////////////////////////////////////////////////////////////////// + protected final Element[] elements; - public Sequence and(Sequence s) { Sequence ret = dup(); ret.needs.add(s); s.needed.add(ret); return ret; } - public Sequence not(Sequence s) { Sequence ret = dup(); ret.hates.add(s); s.hated.add(ret); return ret; } - abstract Sequence _clone(); - Sequence dup() { - Sequence ret = _clone(); - for(Sequence s : needs) { ret.needs.add(s); s.needed.add(ret); } - for(Sequence s : hates) { ret.hates.add(s); s.hated.add(ret); } - ret.noFollow = noFollow; - return ret; - } + boolean needed_or_hated = false; + boolean in_a_union = false; - /** the empty sequence (matches the empty string) */ - public static final Sequence empty = new Sequence.Constant.Empty(); + final HashSet needs = new HashSet(); + final HashSet hates = new HashSet(); - /** after matching the sequence, do not add anything to the output tree */ - public static Sequence drop(Element[] e, boolean lame) { return new Constant.Drop(e, lame); } + // FIXME: these are ugly -- migrate into Cache + HashMap canNeed = new HashMap(); + HashMap canKill = new HashMap(); - /** after matching the sequence, insert a constant into the output tree */ - public static Sequence constant(Element[] e, Object o) { return new Constant(e, o); } + final Position firstp; - /** after matching the sequence, place the result of the idxth match in the output tree */ - public static Sequence singleton(Element[] e, int idx) { return new Singleton(e, idx); } + Atom follow = null; + + // 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); } + + /** 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) { return new RewritingSequence(tag, e, drops); } - - //////////////////////////////////////////////////////////////////////////////// + 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 : Atom.toAtom(noFollow); } + /** return a new sequence identical to this one, but with a positive conjunct s */ + public Sequence and(Sequence s) { + if (s.in_a_union) + throw new RuntimeException("you may not use a sequence as a conjunct if it belongs to a Union"); + 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 Atom.toAtom(elements[0]); + /** return a new sequence identical to this one, but with a negative conjunct s */ + public Sequence andnot(Sequence s) { + if (s.in_a_union) + throw new RuntimeException("you may not use a sequence as a conjunct if it belongs to a Union"); + Sequence ret = dup(); + ret.hates.add(s); + 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 needed = new HashSet(); - final HashSet hated = new HashSet(); - final HashSet needs = new HashSet(); - final HashSet hates = new HashSet(); - public boolean lame = false; + //////////////////////////////////////////////////////////////////////////////// + + abstract Sequence _clone(); + private Sequence dup() { + Sequence ret = _clone(); + for(Sequence s : needs) { ret.needs.add(s); } + for(Sequence s : hates) { ret.hates.add(s); } + ret.follow = follow; + return ret; + } + + Iterable needs() { return needs; } + Iterable hates() { return hates; } - final Position firstp; Position firstp() { return firstp; } + Position lastp() { return firstp().last(); } public Iterator iterator() { return new ArrayIterator(elements); } protected Sequence(Element[] elements) { @@ -71,38 +102,54 @@ public abstract class Sequence extends Element implements Iterable { } // DO NOT MESS WITH THE FOLLOWING LINE!!! - private Forest.Ref epsilonForm = null; - Forest epsilonForm() { + private Forest.Many epsilonForm = null; + Forest epsilonForm(Input.Region loc) { if (epsilonForm!=null) return epsilonForm; - epsilonForm = new Forest.Ref(); - epsilonForm.merge(firstp().rewrite(null, false)); + epsilonForm = new Forest.Many(); + epsilonForm.merge(firstp().rewrite(loc, false)); return epsilonForm; } - protected abstract Forest postReduce(Input.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 implements IntegerMappable { + 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() { + public Forest zero(Input.Region reg) { if (zero != null) return zero; if (pos > 0) throw new Error(); - return zero = rewrite(null); + return zero = rewrite(reg); } final int pos; private final Position next; + private final Position prev; final Forest[] holder; private Position(int pos) { this.pos = pos; this.next = pos==elements.length ? null : new Position(pos+1); this.holder = new Forest[elements.length]; + this.prev = prev; } boolean isFirst() { return pos==0; } @@ -118,19 +165,21 @@ 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; } + public Position last() { return isLast() ? this : next().last(); } + public Position prev() { return prev; } // Position ///////////////////////////////////////////////////////////////////////////////// - final Forest rewrite(Input.Location loc) { return rewrite(loc, true); } - private final Forest rewrite(Input.Location loc, boolean epsilonCheck) { - if (epsilonCheck && this==firstp()) return epsilonForm(); + final 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); - for(int k=0; k ret = Sequence.this.postReduce(loc, holder, this); + //for(int k=0; k { StringBuffer toString(StringBuffer sb) { return toString(sb, true); } StringBuffer toString(StringBuffer sb, boolean spacing) { for(int i=0; i "); + sb.append(follow); + } + for(Sequence s : needs) { + sb.append("& "); + sb.append(s); + } + for(Sequence s : hates) { + sb.append("&~ "); + sb.append(s); + } return sb; } @@ -168,75 +229,72 @@ public abstract class Sequence extends Element implements Iterable { static class Constant extends Sequence { private final Object result; - public Constant(Element[] e, Object result) { super(e); this.result = result; } - Sequence _clone() { return new Constant(elements, result); } - public Forest postReduce(Input.Location loc, Forest[] args) { - return (Forest)Forest.leaf(loc, 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; } - static class Drop extends Constant { - Sequence _clone() { return new Drop(elements, lame); } - public Drop(Element[] e, boolean lame) { - super(e, null); - this.lame = lame; - } + 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 Empty extends Sequence.Constant.Drop { - Sequence _clone() { return new Empty(); } - public Empty() { super(new Element[] { }, false); } } } static class Singleton extends Sequence { private final int idx; public Singleton(Element e) { this(new Element[] { e }, 0); } public Singleton(Element[] e, int idx) { super(e); this.idx = idx; } - public Forest postReduce(Input.Location loc, Forest[] args) { return (Forest)Forest.singleton(loc, args[idx]); } + public Forest postReduce(Input.Region loc, Forest[] args, Position p) { return args[idx]; } Sequence _clone() { return new Singleton(elements,idx); } } - public static class Unwrap extends Sequence { + static class Unwrap extends Sequence { private boolean[] drops; - public Unwrap(Element[] e) { super(e); this.drops = null; } - public Unwrap(Element[] e, boolean[] drops) { super(e); this.drops = drops; } - Sequence _clone() { return new Unwrap(elements, drops); } - public Forest postReduce(Input.Location loc, Forest[] args) { + 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 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 Forest postReduce(Input.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; } } + }