+ /*
+ 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) {
+ reduce(r, pos, target, holder, only, this.pending());
+ }
+ */
+ public void reduce(Position r, int pos, Phase target, Forest[] holder, Node only, Forest pending) {
+ Forest old = holder[pos];
+ holder[pos] = pending;
+ if (pos==0) {
+
+ // 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 (only != null) {
+ for(Forest result : results())
+ for(Node child : ((Forest.Ref<?>)result).parents) {
+ if (child!=only) continue;
+ pending = holder[pos] = result;
+ 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;
+ if (r.pos==1) rex = singularReductions.get(pending, r);
+ if (rex==null) {
+ rex = r.rewrite(phase().getLocation());
+ if (r.pos==1) singularReductions.put(pending, r, rex);
+ }
+ only.finish(r, rex, target, holder);
+ }
+ } else {
+ for(Forest result : results()) {
+ pending = holder[pos] = result;
+ 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;
+ if (rex==null && r.pos==1) rex = singularReductions.get(pending, r);
+ if (rex==null) {
+ rex = r.rewrite(phase().getLocation());
+ if (r.pos==1) singularReductions.put(pending, r, rex);
+ }
+ for(Node child : ((Forest.Ref<?>)result).parents)
+ child.finish(r, rex, target, holder);
+ }
+ }
+ } else {
+ if (only != null) {
+ for(Forest result : results())
+ for(Node child : ((Forest.Ref<?>)result).parents) {
+ if (child!=only) continue;
+ holder[pos] = result;
+ only.reduce(r, pos-1, target, holder, null, null);
+ }
+ } else {
+ for(Forest result : results())
+ for(Node child : ((Forest.Ref<?>)result).parents) {
+ holder[pos] = result;
+ child.reduce(r, pos-1, target, holder, null, null);
+ }
+ }
+ }
+ holder[pos] = old;
+ }