+// Copyright 2006 all rights reserved; see LICENSE file for BSD-style license
+
package edu.berkeley.sbp;
import edu.berkeley.sbp.*;
import edu.berkeley.sbp.util.*;
/** a parser which translates an Input<Token> into a Forest<NodeType> */
public abstract class Parser<Token, NodeType> {
-
protected final Table<Token> pt;
/** create a parser to parse the grammar with start symbol <tt>u</tt> */
/** parse <tt>input</tt>, and return the shared packed parse forest (or throw an exception) */
public Forest<NodeType> parse(Input<Token> input) throws IOException, ParseFailed {
- GSS gss = new GSS();
+ GSS gss = new GSS(input);
Input.Location loc = input.getLocation();
Token tok = input.next();
- GSS.Phase current = gss.new Phase<Token>(null, this, null, tok, loc, input.getLocation(), null);
- current.newNode(null, Forest.create(loc.createRegion(loc), null, null, false), pt.start, true);
+ GSS.Phase current = gss.new Phase<Token>(null, null, tok, loc, input.getLocation(), null);
+ current.newNode(new Result(Forest.create(loc.createRegion(loc), null, null, false), null, null), pt.start, true);
int count = 1;
for(int idx=0;;idx++) {
Input.Location oldloc = loc;
Forest forest = current.token==null ? null : shiftToken((Token)current.token, loc);
loc = input.getLocation();
Token nextToken = input.next();
- GSS.Phase next = gss.new Phase<Token>(current, this, current, nextToken, loc, input.getLocation(), forest);
- if (!helpgc) {
- FileOutputStream fos = new FileOutputStream("out-"+idx+".dot");
- PrintWriter p = new PrintWriter(new OutputStreamWriter(fos));
- GraphViz gv = new GraphViz();
- for(Object n : next)
- ((GSS.Phase.Node)n).toGraphViz(gv);
- gv.dump(p);
- p.flush();
- p.close();
- }
+ GSS.Phase next = gss.new Phase<Token>(current, current, nextToken, loc, input.getLocation(), forest);
+
+ /*
+ FileOutputStream fos = new FileOutputStream("out-"+idx+".dot");
+ PrintWriter p = new PrintWriter(new OutputStreamWriter(fos));
+ GraphViz gv = new GraphViz();
+ for(Object n : current)
+ ((Node)n).toGraphViz(gv);
+ gv.dump(p);
+ p.flush();
+ p.close();
+ */
+
count = next.size();
if (current.isDone()) return (Forest<NodeType>)gss.finalResult;
current = next;
sb.append(" reduce \""+
new edu.berkeley.sbp.chr.CharTopology((IntegerTopology<Character>)t)+"\" => " +
state.reductions.getAll(t) + "\n");
+ for(Sequence s : state.gotoSetNonTerminals.keySet())
+ sb.append(" goto "+state.gotoSetNonTerminals.get(s)+" from " + s + "\n");
}
return sb.toString();
}
/** used to generate unique values for State.idx */
private int master_state_idx = 0;
HashMap<HashSet<Position>,State<Token>> all_states = new HashMap<HashSet<Position>,State<Token>>();
+ HashSet<SequenceOrElement> all_elements = new HashSet<SequenceOrElement>();
/** construct a parse table for the given grammar */
public Table(Topology top) { this("s", top); }
cache.eof.put(start0, true);
// construct the set of states
- HashSet<SequenceOrElement> all_elements = new HashSet<SequenceOrElement>();
walk(start0, all_elements);
for(SequenceOrElement e : all_elements)
cache.ys.addAll(e, new Walk.YieldSet(e, cache).walk());
+ for(SequenceOrElement e : all_elements)
+ cache.ys2.addAll(e, new Walk.YieldSet2(e, cache).walk());
HashSet<Position> hp = new HashSet<Position>();
reachable(start0, hp);
- this.dead_state = new State<Token>(new HashSet<Position>(), all_states, all_elements);
- this.start = new State<Token>(hp, all_states, all_elements);
+ this.dead_state = new State<Token>(new HashSet<Position>());
+ this.start = new State<Token>(hp);
// for each state, fill in the corresponding "row" of the parse table
for(State<Token> state : all_states.values())
if (isRightNullable(p)) {
Walk.Follow wf = new Walk.Follow(top.empty(), p.owner(), all_elements, cache);
Topology follow = wf.walk(p.owner());
- for(Position p2 = p; p2 != null && p2.element() != null; p2 = p2.next())
+ for(Position p2 = p; p2 != null && p2.element() != null; p2 = p2.next()) {
+ Atom set = new Walk.EpsilonFollowSet(new edu.berkeley.sbp.chr.CharAtom(top.empty().complement()),
+ new edu.berkeley.sbp.chr.CharAtom(top.empty()),
+ cache).walk(p2.element());
follow = follow.intersect(new Walk.Follow(top.empty(), p2.element(), all_elements, cache).walk(p2.element()));
+ if (set != null) follow = follow.intersect(set.getTokenTopology());
+ }
state.reductions.put(follow, p);
if (wf.includesEof()) state.eofReductions.add(p);
}
/** a single state in the LR table and the transitions possible from it */
- class State<Token> implements Comparable<State<Token>>, IntegerMappable, Iterable<Position> {
+ class State<Token> implements IntegerMappable, Iterable<Position> {
public final int idx = master_state_idx++;
private final HashSet<Position> hs;
+ public HashSet<State<Token>> also = new HashSet<State<Token>>();
public transient HashMap<Sequence,State<Token>> gotoSetNonTerminals = new HashMap<Sequence,State<Token>>();
private transient TopologicalBag<Token,State<Token>> gotoSetTerminals = new TopologicalBag<Token,State<Token>>();
/**
* create a new state consisting of all the <tt>Position</tt>s in <tt>hs</tt>
* @param hs the set of <tt>Position</tt>s comprising this <tt>State</tt>
- * @param all_states the set of states already constructed (to avoid recreating states)
* @param all_elements the set of all elements (Atom instances need not be included)
*
* In principle these two steps could be merged, but they
* for non-Atom Elements.
* </ul>
*/
- public State(HashSet<Position> hs,
- HashMap<HashSet<Position>,State<Token>> all_states,
- HashSet<SequenceOrElement> all_elements) {
+ public State(HashSet<Position> hs) { this(hs, false); }
+ public boolean special;
+ public State(HashSet<Position> hs, boolean special) {
this.hs = hs;
+ this.special = special;
// register ourselves in the all_states hash so that no
// two states are ever created with an identical position set
- all_states.put(hs, this);
+ ((HashMap)all_states).put(hs, this);
+
+ for(Position p : hs) {
+ if (!p.isFirst()) continue;
+ for(Sequence s : p.owner().needs()) {
+ if (hs.contains(s.firstp())) continue;
+ HashSet<Position> h2 = new HashSet<Position>();
+ reachable(s.firstp(), h2);
+ also.add((State<Token>)(all_states.get(h2) == null ? (State)new State<Token>(h2,true) : (State)all_states.get(h2)));
+ }
+ for(Sequence s : p.owner().hates()) {
+ if (hs.contains(s.firstp())) continue;
+ HashSet<Position> h2 = new HashSet<Position>();
+ reachable(s, h2);
+ also.add((State<Token>)(all_states.get(h2) == null ? (State)new State<Token>(h2,true) : (State)all_states.get(h2)));
+ }
+ }
// Step 1a: examine all Position's in this state and compute the mappings from
// sets of follow tokens (tokens which could follow this position) to sets
for(Topology<Token> r : bag0) {
HashSet<Position> h = new HashSet<Position>();
for(Position p : bag0.getAll(r)) h.add(p);
- gotoSetTerminals.put(r, all_states.get(h) == null ? new State<Token>(h, all_states, all_elements) : all_states.get(h));
+ ((TopologicalBag)gotoSetTerminals).put(r, all_states.get(h) == null
+ ? new State<Token>(h) : all_states.get(h));
}
// Step 2: for every non-Atom element (ie every Element which has a corresponding reduction),
for(Position p : hs) {
Element e = p.element();
if (e==null) continue;
- for(SequenceOrElement y : cache.ys.getAll(e)) {
+ for(SequenceOrElement y : cache.ys2.getAll(e)) {
+ //System.out.println(e + " yields " + y);
HashSet<Position> hp = new HashSet<Position>();
reachable(p.next(), hp);
move.addAll(y, hp);
}
OUTER: for(SequenceOrElement y : move) {
HashSet<Position> h = move.getAll(y);
- State<Token> s = all_states.get(h) == null ? new State<Token>(h, all_states, all_elements) : all_states.get(h);
+ State<Token> s = all_states.get(h) == null ? (State)new State<Token>(h) : (State)all_states.get(h);
// if a reduction is "lame", it should wind up in the dead_state after reducing
if (y instanceof Sequence) {
for(Position p : hs) {
return ret.toString();
}
- public int compareTo(State<Token> s) { return idx==s.idx ? 0 : idx < s.idx ? -1 : 1; }
+ public Walk.Cache cache() { return cache; }
public int toInt() { return idx; }
}
}
private static void reachable(Sequence s, HashSet<Position> h) {
reachable(s.firstp(), h);
- for(Sequence ss : s.needs()) reachable(ss, h);
- for(Sequence ss : s.hates()) reachable(ss, h);
+ //for(Sequence ss : s.needs()) reachable(ss, h);
+ //for(Sequence ss : s.hates()) reachable(ss, h);
}
private static void reachable(Element e, HashSet<Position> h) {
if (e instanceof Atom) return;
projects / sbp.git / blobdiff