}
public String toString() { return "[reduce " + position + "]"; }
+ private Forest zero = null;
+ public Forest zero() {
+ if (zero != null) return zero;
+ if (numPop > 0) throw new Error();
+ return zero = position.rewrite(null);
+ }
+
public Forest reduce(GSS.Phase.Node parent) {
- Forest rex = numPop==0 ? zero() : null;
- Forest ret = reduce(parent, numPop-1, rex, null, parent.phase());
- return ret;
+ if (numPop==0) return finish(parent, zero(), parent.phase());
+ return reduce(parent, numPop-1, null, parent.phase());
}
public Forest reduce(GSS.Phase.Node parent, GSS.Phase.Node onlychild) {
+ if (numPop<=0) throw new Error("called wrong form of reduce()");
int pos = numPop-1;
- if (pos>=0) holder[pos] = parent.pending();
- Forest rex = null;
+ holder[pos] = parent.pending();
if (pos==0) {
- if (rex==null) {
- System.arraycopy(holder, 0, position.holder, 0, holder.length);
- rex = position.rewrite(parent.phase().getLocation());
- }
+ System.arraycopy(holder, 0, position.holder, 0, holder.length);
+ return finish(onlychild, position.rewrite(parent.phase().getLocation()), parent.phase());
}
- return reduce(onlychild, pos-1, rex, null, parent.phase());
- }
-
- private Forest zero = null;
- public Forest zero() {
- if (zero != null) return zero;
- if (numPop > 0) throw new Error();
- return zero = position.rewrite(null);
+ return reduce(onlychild, pos-1, null, parent.phase());
}
// FIXME: this could be more elegant and/or cleaner and/or somewhere else
- private Forest reduce(GSS.Phase.Node parent, int pos, Forest rex, GSS.Phase.Node onlychild, GSS.Phase target) {
- if (pos>=0) holder[pos] = parent.pending();
- if (pos==0) {
- if (rex==null) {
- System.arraycopy(holder, 0, position.holder, 0, holder.length);
- rex = position.rewrite(target.getLocation());
- }
- if (onlychild != null)
- reduce(onlychild, pos-1, rex, null, target);
- else
- for(GSS.Phase.Node child : parent.parents())
- reduce(child, pos-1, rex, null, target);
- } else if (pos>0) {
- if (onlychild != null)
- reduce(onlychild, pos-1, rex, null, target);
- else
- for(GSS.Phase.Node child : parent.parents())
- reduce(child, pos-1, rex, null, target);
- } else {
- State state = parent.state.gotoSetNonTerminals.get(position.owner());
- if (state!=null)
- target.newNode(parent, rex, state, numPop<=0, parent.phase());
+ private Forest reduce(GSS.Phase.Node parent, int pos, Forest rex, GSS.Phase target) {
+ if (pos<0) return finish(parent, rex, target);
+ holder[pos] = parent.pending();
+ if (pos==0 && rex==null) {
+ System.arraycopy(holder, 0, position.holder, 0, holder.length);
+ rex = position.rewrite(target.getLocation());
}
+ for(GSS.Phase.Node child : parent.parents())
+ if (pos==0) finish(child, rex, target);
+ else reduce(child, pos-1, rex, target);
return rex;
}
+ private Forest finish(GSS.Phase.Node parent, Forest result, GSS.Phase target) {
+ State state = parent.state.gotoSetNonTerminals.get(position.owner());
+ if (state!=null)
+ target.newNode(parent, result, state, numPop<=0, parent.phase());
+ return result;
+ }
}
}