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inline predictATN into adaptivePredict

This commit is contained in:
Terence Parr 2013-04-25 17:39:37 -07:00
parent c9ceb48a3c
commit eb9eb17aa2
1 changed files with 26 additions and 47 deletions
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73
runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java
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@ -325,22 +325,31 @@ public class ParserATNSimulator extends ATNSimulator {
predict_calls++;
DFA dfa = decisionToDFA[decision];
// Now we are certain to have a specific decision's DFA
// But, do we still need an initial state?
if ( dfa.s0==null ) {
try {
return predictATN(dfa, input, outerContext);
}
finally {
mergeCache = null; // wack cache after each prediction
}
}
// We can start with an existing DFA
int m = input.mark();
int index = input.index();
// Now we are certain to have a specific decision's DFA
// But, do we still need an initial state?
try {
return execATN(dfa, dfa.s0, input, index, outerContext);
if ( dfa.s0==null ) {
if ( outerContext ==null ) outerContext = ParserRuleContext.EMPTY;
if ( debug || debug_list_atn_decisions ) {
System.out.println("predictATN decision "+ dfa.decision+
" exec LA(1)=="+ getLookaheadName(input) +
", outerContext="+ outerContext.toString(parser));
}
boolean fullCtx = false;
ATNConfigSet s0_closure =
computeStartState(dfa.atnStartState,
ParserRuleContext.EMPTY,
fullCtx);
dfa.s0 = addDFAState(dfa, new DFAState(s0_closure));
}
// We can start with an existing DFA
int alt = execATN(dfa, dfa.s0, input, index, outerContext);
if ( debug ) System.out.println("DFA after predictATN: "+ dfa.toString(parser.getTokenNames()));
return alt;
}
finally {
mergeCache = null; // wack cache after each prediction
@ -349,40 +358,6 @@ public class ParserATNSimulator extends ATNSimulator {
}
}
protected int predictATN(@NotNull DFA dfa, @NotNull TokenStream input,
@Nullable ParserRuleContext outerContext)
{
if ( outerContext==null ) outerContext = ParserRuleContext.EMPTY;
if ( debug || debug_list_atn_decisions ) {
System.out.println("predictATN decision "+dfa.decision+
" exec LA(1)=="+ getLookaheadName(input) +
", outerContext="+outerContext.toString(parser));
}
boolean fullCtx = false;
ATNConfigSet s0_closure =
computeStartState(dfa.atnStartState,
ParserRuleContext.EMPTY,
fullCtx);
dfa.s0 = addDFAState(dfa, new DFAState(s0_closure));
int alt = 0;
int m = input.mark();
int index = input.index();
try {
alt = execATN(dfa, dfa.s0, input, index, outerContext);
}
catch (NoViableAltException nvae) {
if ( debug ) dumpDeadEndConfigs(nvae);
throw nvae;
}
finally {
input.seek(index);
input.release(m);
}
if ( debug ) System.out.println("DFA after predictATN: "+dfa.toString(parser.getTokenNames()));
return alt;
}
/** Performs ATN simulation to compute a predicted alternative based
* upon the remaining input, but also updates the DFA cache to avoid
* having to traverse the ATN again for the same input sequence.
@ -1378,6 +1353,10 @@ public class ParserATNSimulator extends ATNSimulator {
return getTokenName(input.LA(1));
}
/** Used for debugging in adaptivePredict around execATN but I cut
* it out for clarity now that alg. works well. We can leave this
* "dead" code for a bit.
*/
public void dumpDeadEndConfigs(@NotNull NoViableAltException nvae) {
System.err.println("dead end configs: ");
for (ATNConfig c : nvae.getDeadEndConfigs()) {