- /** perform the reduction */
- public void go() {
- if (done) return;
- done = true;
- pendingReduct.remove(this);
- pendingReductions--;
-
- if (r==null) {
- for(Parser.Table.Reduction r : token==null ? n.state.getEofReductions() : n.state.getReductions(token)) {
-
- // UGLY HACK
- // The problem here is that a "reduction of length 1"
- // performed twice with different values of n2 needs
- // to only create a *single* new result, but must add
- // multiple parents to the node holding that result.
- // The current reducer doesn't differentiate between
- // the next node of an n-pop reduction and the
- // ultimate parent of the last pop, so we need to
- // cache instances here as a way of avoiding
- // recreating them.
-
- // currently we have this weird problem where we
- // have to do an individual reduct for each child
- // when the reduction length is one (ie the
- // children wind up being children of the newly
- // created node rather than part of the popped
- // sequence
- if (r.numPop <= 0) continue;
- if (r.numPop == 1) {
- Forest ret = n.cache().get(r);
- if (ret != null) r.reduce(n, n2, n.phase, ret);
- else n.cache().put(r, r.reduce(n, n2, n.phase, null));
- } else {
- r.reduce(n, n2, Phase.this, null);
+ /*
+ 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) {
+ holder[pos] = pending(only);
+ 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 : parents()) {
+ if (pending(child)==result)
+ child.finish(r, rex, target, holder);
+ }
+ }
+ }
+ } else {
+ if (only != null) {
+ holder[pos] = pending(only);
+ only.reduce(r, pos-1, target, holder, null, only.pending(only));
+ } else {
+ for(Node child : this.parents()) {
+ holder[pos] = pending(child);
+ child.reduce(r, pos-1, target, holder, null, child.pending(child));