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Disable local context compression for full-context parsing

This commit is contained in:
Sam Harwell 2012-02-09 14:44:02 -06:00
parent 2b6e2110fb
commit c586224f61
2 changed files with 32 additions and 18 deletions
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48
runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java
View File

@ -297,9 +297,10 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
" exec LA(1)=="+ getLookaheadName(input) +
", outerContext="+outerContext.toString(parser));
DecisionState decState = atn.getDecisionState(dfa.decision);
boolean greedy = decState.isGreedy;
boolean loopsSimulateTailRecursion = false;
ATNConfigSet s0_closure = computeStartState(dfa.atnStartState, ParserRuleContext.EMPTY, greedy, loopsSimulateTailRecursion);
final boolean fullContext = false;
final boolean greedy = decState.isGreedy;
final boolean loopsSimulateTailRecursion = false;
ATNConfigSet s0_closure = computeStartState(dfa.atnStartState, ParserRuleContext.EMPTY, fullContext, greedy, loopsSimulateTailRecursion);
dfa.s0 = addDFAState(dfa, s0_closure);
int alt = 0;
@ -341,8 +342,9 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
if ( dfa_debug ) System.out.println("DFA state "+s.stateNumber+" LA(1)=="+getLookaheadName(input));
if ( s.isCtxSensitive ) {
if ( dfa_debug ) System.out.println("ctx sensitive state "+outerContext+" in "+s);
boolean loopsSimulateTailRecursion = true;
ATNConfigSet s0_closure = computeStartState(dfa.atnStartState, outerContext, greedy, loopsSimulateTailRecursion);
final boolean fullContext = false;
final boolean loopsSimulateTailRecursion = true;
ATNConfigSet s0_closure = computeStartState(dfa.atnStartState, outerContext, fullContext, greedy, loopsSimulateTailRecursion);
int prediction =
execATNWithFullContext(dfa, s, s0_closure,
input, startIndex,
@ -491,8 +493,9 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
boolean greedy = decState.isGreedy;
while (true) { // while more work
boolean fullContext = false;
boolean loopsSimulateTailRecursion = false;
ATNConfigSet reach = computeReachSet(previous, t, greedy, loopsSimulateTailRecursion);
ATNConfigSet reach = computeReachSet(previous, t, fullContext, greedy, loopsSimulateTailRecursion);
if ( reach==null ) throw noViableAlt(input, outerContext, previous, startIndex);
D = addDFAEdge(dfa, previous, t, reach); // always adding edge even if to a conflict state
int predictedAlt = getUniqueAlt(reach);
@ -519,8 +522,9 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
}
else {
if ( debug ) System.out.println("RETRY with outerContext="+outerContext);
fullContext = true;
loopsSimulateTailRecursion = true;
ATNConfigSet s0_closure = computeStartState(dfa.atnStartState, outerContext, greedy, loopsSimulateTailRecursion);
ATNConfigSet s0_closure = computeStartState(dfa.atnStartState, outerContext, fullContext, greedy, loopsSimulateTailRecursion);
predictedAlt = execATNWithFullContext(dfa, D, s0_closure,
input, startIndex,
outerContext,
@ -607,7 +611,8 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
input.seek(startIndex);
int t = input.LA(1);
while (true) { // while more work
reach = computeReachSet(previous, t, greedy, true);
final boolean fullContext = true;
reach = computeReachSet(previous, t, fullContext, greedy, true);
if ( reach==null ) {
throw noViableAlt(input, outerContext, previous, startIndex);
}
@ -656,9 +661,9 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
return prediction;
}
protected ATNConfigSet computeReachSet(ATNConfigSet closure, int t, boolean greedy, boolean loopsSimulateTailRecursion) {
protected ATNConfigSet computeReachSet(ATNConfigSet closure, int t, boolean fullContext, boolean greedy, boolean loopsSimulateTailRecursion) {
if ( debug ) System.out.println("in computeReachSet, starting closure: " + closure);
ATNConfigSet reach = new ATNConfigSet(true);
ATNConfigSet reach = new ATNConfigSet(!fullContext);
for (ATNConfig c : closure) {
if ( debug ) System.out.println("testing "+getTokenName(t)+" at "+c.toString());
int n = c.state.getNumberOfTransitions();
@ -667,7 +672,8 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
ATNState target = getReachableTarget(trans, t);
if ( target!=null ) {
Set<ATNConfig> closureBusy = new HashSet<ATNConfig>();
closure(new ATNConfig(c, target), reach, closureBusy, false, greedy, loopsSimulateTailRecursion);
final boolean collectPredicates = false;
closure(new ATNConfig(c, target), reach, closureBusy, collectPredicates, fullContext, greedy, loopsSimulateTailRecursion);
}
}
}
@ -678,16 +684,18 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
@NotNull
public ATNConfigSet computeStartState(@NotNull ATNState p,
@Nullable RuleContext ctx,
boolean fullContext,
boolean greedy, boolean loopsSimulateTailRecursion)
{
PredictionContext initialContext = PredictionContext.fromRuleContext(ctx); // always at least the implicit call to start rule
ATNConfigSet configs = new ATNConfigSet(true);
ATNConfigSet configs = new ATNConfigSet(!fullContext);
for (int i=0; i<p.getNumberOfTransitions(); i++) {
ATNState target = p.transition(i).target;
ATNConfig c = new ATNConfig(target, i+1, initialContext);
Set<ATNConfig> closureBusy = new HashSet<ATNConfig>();
closure(c, configs, closureBusy, true, greedy, loopsSimulateTailRecursion);
final boolean collectPredicates = true;
closure(c, configs, closureBusy, collectPredicates, fullContext, greedy, loopsSimulateTailRecursion);
}
return configs;
@ -841,12 +849,14 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
@NotNull ATNConfigSet configs,
@NotNull Set<ATNConfig> closureBusy,
boolean collectPredicates,
boolean fullContext,
boolean greedy, boolean loopsSimulateTailRecursion)
{
if ( debug ) System.out.println("closure("+config.toString(parser,true)+")");
if ( !closureBusy.add(config) ) return; // avoid infinite recursion
boolean hasMoreContexts = !fullContext;
boolean hasEmpty = config.context == null || config.context.isEmpty();
if ( config.state instanceof RuleStopState ) {
if ( !greedy ) {
@ -873,15 +883,19 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
// gotten that context AFTER having fallen off a rule.
// Make sure we track that we are now out of context.
c.reachesIntoOuterContext = config.reachesIntoOuterContext;
closure(c, configs, closureBusy, collectPredicates, greedy, loopsSimulateTailRecursion);
closure(c, configs, closureBusy, collectPredicates, fullContext, greedy, loopsSimulateTailRecursion);
}
if (!hasEmpty) {
if (!hasEmpty || !hasMoreContexts) {
return;
}
config = new ATNConfig(config, config.state, PredictionContext.EMPTY);
}
else if (!hasMoreContexts) {
configs.add(config);
return;
}
else {
// else if we have no context info, just chase follow links (if greedy)
if ( debug ) System.out.println("FALLING off rule "+
@ -924,7 +938,7 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
}
ATNConfig extraConfig = new ATNConfig(config, config.state, remainingContext);
closure(extraConfig, configs, closureBusy, collectPredicates, greedy, loopsSimulateTailRecursion);
closure(extraConfig, configs, closureBusy, collectPredicates, fullContext, greedy, loopsSimulateTailRecursion);
p = config.context = config.context.parents[loopbackIndex];
continue;
}
@ -957,7 +971,7 @@ public class ParserATNSimulator<Symbol> extends ATNSimulator {
c.reachesIntoOuterContext++;
if ( debug ) System.out.println("dips into outer ctx: "+c);
}
closure(c, configs, closureBusy, continueCollecting, greedy, loopsSimulateTailRecursion);
closure(c, configs, closureBusy, continueCollecting, fullContext, greedy, loopsSimulateTailRecursion);
}
}
}

2
tool/test/org/antlr/v4/test/TestNonGreedyLoops.java
View File

@ -528,7 +528,7 @@ public class TestNonGreedyLoops extends BaseTest {
"s0-'>'->:s2=>2\n" +
"s0-ID->:s1=>1\n", found);
assertEquals("line 1:6 reportAttemptingFullContext d=1: [(20,1,[14 6]), (16,2,[6])], input='<a>foo<'\n" +
"line 1:6 reportAmbiguity d=1: ambigAlts={1..2}:[(26,1,[14 6 10 10]), (26,1,[32 32 32 32 14 6]), (33,1,[14 6]), (22,1,[14 6 10 10]), (20,1,[14 6 10 10 10]), (16,1,[6 10 10 10]), (1,1,[]), (22,2,[14 6 10 10 10 10]), (26,2,[14 6 10 10 10 10]), (33,2,[14 6 10 10 10 10]), (20,2,[14 6 10 10 10 10 10]), (16,2,[6 10 10 10 10 10]), (1,2,[])],conflictingAlts={1..2}, input='<a>foo<'\n" +
"line 1:6 reportAmbiguity d=1: ambigAlts={1..2}:[(26,1,[14 6 10 10]), (26,1,[32 32 32 32 14 6]), (33,1,[14 6 10 10]), (33,1,[14 6]), (22,1,[14 6 10 10]), (20,1,[14 6 10 10 10]), (16,1,[6 10 10 10]), (1,1,[]), (22,2,[14 6 10 10 10 10]), (26,2,[14 6 10 10 10 10]), (33,2,[14 6 10 10 10 10]), (20,2,[14 6 10 10 10 10 10]), (16,2,[6 10 10 10 10 10]), (1,2,[])],conflictingAlts={1..2}, input='<a>foo<'\n" +
"line 1:10 reportAttemptingFullContext d=1: [(20,1,[14 6]), (16,2,[6])], input='</a>'\n" +
"line 1:10 reportAmbiguity d=1: ambigAlts={1..2}:[(35,1,[]), (35,2,[])],conflictingAlts={1..2}, input='</a>'\n" +
"line 1:7 reportAmbiguity d=2: ambigAlts={1..2}:[(26,1,[]), (33,1,[]), (26,2,[]), (33,2,[])],conflictingAlts={1..2}, input='/'\n",