X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FSequence.java;h=95353572a770f88b3952a65f43ba63cbbf2e6432;hb=a09bae7235677c1b3b77f827bdd6722a9e88a122;hp=2530a211cf0a996591a4248f6ab83e447fa66579;hpb=9b031db4cefc550c82a8bb6da3b061d3790c2cdc;p=sbp.git
diff --git a/src/edu/berkeley/sbp/Sequence.java b/src/edu/berkeley/sbp/Sequence.java
index 2530a21..9535357 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.*;
@@ -8,7 +10,7 @@ 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 {
+public abstract class Sequence implements Iterable, SequenceOrElement {
protected final Element[] elements;
@@ -39,25 +41,25 @@ public abstract class Sequence extends Element implements Iterable {
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 idx) { return new Singleton(e, idx); }
-
- /** after matching the sequence, insert a constant into the output tree */
- public static Sequence newConstantSequence(Element[] e, Object o) { return new Constant(e, o); }
+ 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
+ * create a sequence (general form)
+ * @param head the head of the output tree
* @param e the elements to match
- * @param drops only elements of e whose corresponding boolean in drops
+ * @param drop only elements of e whose corresponding boolean in drops
* is false will be included in the output tree
- * @param unwrap 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 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 create(Object tag, Element[] e, boolean[] drops, boolean unwrap) {
- return unwrap
- ? new Unwrap(e, tag, drops)
- : 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);
}
////////////////////////////////////////////////////////////////////////////////
@@ -66,7 +68,7 @@ public abstract class Sequence extends Element implements Iterable {
public Sequence and(Sequence s) { Sequence ret = dup(); ret.needs.add(s); return ret; }
/** return a new sequence identical to this one, but with a negative conjunct s */
- public Sequence not(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); return ret; }
/** 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; }
@@ -84,10 +86,10 @@ public abstract class Sequence extends Element implements Iterable {
// DO NOT MESS WITH THE FOLLOWING LINE!!!
private Forest.Many epsilonForm = null;
- Forest epsilonForm() {
+ Forest epsilonForm(Input.Region loc) {
if (epsilonForm!=null) return epsilonForm;
epsilonForm = new Forest.Many();
- epsilonForm.merge(firstp().rewrite(null, false));
+ epsilonForm.merge(firstp().rewrite(loc, false));
return epsilonForm;
}
@@ -100,10 +102,10 @@ public abstract class Sequence extends Element implements Iterable {
class Position implements IntegerMappable {
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);
}
@@ -135,10 +137,10 @@ public abstract class Sequence extends Element implements Iterable {
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();
+ if (epsilonCheck && this==firstp()) return epsilonForm(loc);
for(int i=0; i ret = Sequence.this.postReduce(loc, holder, this);
@@ -176,6 +178,14 @@ public abstract class Sequence extends Element implements Iterable {
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;
}