+ public void reduce(Position r, int pos, Phase target, Forest[] holder) { reduce(r, pos, target, holder, null); }
+ public void reduce(Position r, int pos, Phase target, Forest[] holder, Node only) {
+ Forest old = holder[pos];
+ holder[pos] = this.pending();
+ if (pos==0) {
+ System.arraycopy(holder, 0, r.holder, 0, holder.length);
+ for(int i=0; i<r.pos; i++) if (r.holder[i]==null) throw new Error("realbad");
+ Forest rex = null;
+
+ // FIXME: I'm unsure about this -- basically we want to deal with the case where
+ // there are two nodes, each of whose Ref points to the same Forest instance.
+ // Some node in the next phase has both of these as parents. This might happen
+ // since the same reduction can appear in more than one state.
+ if (r.pos==1) rex = singularReductions.get(this.pending(), r);
+ if (rex==null) {
+ rex = r.rewrite(phase().getLocation());
+ if (r.pos==1) singularReductions.put(this.pending(), r, rex);
+ }
+ if (only != null) only.finish(r, rex, target, holder);
+ else for(Node child : this.parents()) child.finish(r, rex, target, holder);
+ } else {
+ if (only != null) only.reduce(r, pos-1, target, holder);
+ else for(Node child : this.parents()) child.reduce(r, pos-1, target, holder);
+ }
+ holder[pos] = old;
+ }