-
- /** perform all shift operations, adding promoted nodes to <tt>next</tt> */
- public void shift(Phase next, Forest result) {
- closed = true;
- Forest res = null;
- boolean ok = false;
- for(Phase.Node n : hash.values()) {
- if (n.holder==null) continue;
- n.holder.resolve();
- if (token == null && n.state.isAccepting()) {
- ok = true;
- if (finalResult==null) finalResult = new Forest.Ref();
- finalResult.merge(n.holder);
- }
- if (!n.holder.valid()) continue;
- if (token == null) continue;
- for(Parser.Table.State st : n.state.getShifts(token)) {
- if (res == null) res = result;
- next.newNode(n, res, st, true, this);
- ok = true;
- }
- }
-
- if (!ok && token != null) {
- StringBuffer error = new StringBuffer();
- error.append("error: unable to shift token \"" + token + "\"\n");
- //error.append(" before: " +pendingReductions+ "\n");
- //error.append(" before: " +totalReductions+ "\n");
- //for(Phase.Node n : hash.values()) {
- //n.queueReductions();
- //n.queueEmptyReductions();
- //}
- //error.append(" after: " +pendingReductions+ "\n");
- //error.append(" candidate states:\n");
- //for(Phase.Node n : hash.values()) {
- //for(Sequence.Position p : n.state) error.append(" " + p + "\n");
- //error.append(" --\n");
- //for(Parser.Table.Reduction r : n.state.getReductions(token)) error.append(" " + r + "\n");
- //error.append(" ==\n");
- //}
- next.error = error.toString();
- }
-
- // this massively improves GC performance
- hash = null;
- }
-
-
- // GSS Nodes //////////////////////////////////////////////////////////////////////////////
-
- /** a node in the GSS */
- public final class Node extends FastSet<Node> {
-
- public void addParent(Node parent, boolean fromEmptyReduction) {
- parents().add(parent, true);
- if (this!=parent && !fromEmptyReduction) queueReductions(parent);
- }
-
- private Forest.Ref holder = null;
- private boolean allqueued = false;
-
- /** what state this node is in */
- public final Parser.Table.State state;
-
- /** which Phase this Node belongs to (node that Node is also a non-static inner class of Phase) */
- public Phase phase() { return Phase.this; }
-
- public Forest.Ref holder() { return holder==null ? (holder = new Forest.Ref()) : holder; }
- public Forest pending() { return Phase.this.closed ? holder().resolve() : holder; }
- public FastSet<Node> parents() { return this; }
-
- public void queueReductions() {
- if (allqueued) return;
- allqueued = true;
- int where = parents().size();
- for(Parser.Table.Reduction r : state.getReductions(token))
- if (r.numPop >= 1)
- r.reduce(this, null, null);
- }
-
- public void queueReductions(Node n2) {
- if (!allqueued) { queueReductions(); return; }
- for(Parser.Table.Reduction r : state.getReductions(token))
- if (r.numPop > 0)
- r.reduce(this, n2);
- }
-
-
- public void queueEmptyReductions() {
- if (reducing)
- for(Parser.Table.Reduction r : token==null ? state.getEofReductions() : state.getReductions(token))
- if (r.numPop==0)
- r.reduce(this, null, r.zero());
- }
-
- private Node(Node parent, Forest pending, Parser.Table.State state, Phase start) {
- this.state = state;
- if (pending != null) this.holder().merge(pending);
- if (parent != null) parents().add(parent, true);
- if (Phase.this.hash.get(code(state, start)) != null) throw new Error("severe problem!");
- Phase.this.hash.put(code(state, start), this);
- Phase.this.numNodes++;
- if (parent==null) holder().valid = true; // hack to make sure that the "base" node is always considered valid
- }