Examples with DFAState org.antlr.v4.runtime.dfa.DFAState used on opensource projects

Example 31 with DFAState

use of org.antlr.v4.runtime.dfa.DFAState in project antlr4 by tunnelvisionlabs.

the class LexerATNSimulator method addDFAState.

/**
 * Add a new DFA state if there isn't one with this set of
 *		configurations already. This method also detects the first
 *		configuration containing an ATN rule stop state. Later, when
 *		traversing the DFA, we will know which rule to accept.
 */
@NotNull
protected DFAState addDFAState(@NotNull ATNConfigSet configs) {
    /* the lexer evaluates predicates on-the-fly; by this point configs
		 * should not contain any configurations with unevaluated predicates.
		 */
    assert !configs.hasSemanticContext();
    DFAState proposed = new DFAState(atn.modeToDFA[mode], configs);
    DFAState existing = atn.modeToDFA[mode].states.get(proposed);
    if (existing != null)
        return existing;
    configs.optimizeConfigs(this);
    DFAState newState = new DFAState(atn.modeToDFA[mode], configs.clone(true));
    ATNConfig firstConfigWithRuleStopState = null;
    for (ATNConfig c : configs) {
        if (c.getState() instanceof RuleStopState) {
            firstConfigWithRuleStopState = c;
            break;
        }
    }
    if (firstConfigWithRuleStopState != null) {
        int prediction = atn.ruleToTokenType[firstConfigWithRuleStopState.getState().ruleIndex];
        LexerActionExecutor lexerActionExecutor = firstConfigWithRuleStopState.getLexerActionExecutor();
        newState.setAcceptState(new AcceptStateInfo(prediction, lexerActionExecutor));
    }
    return atn.modeToDFA[mode].addState(newState);
}

Example 32 with DFAState

use of org.antlr.v4.runtime.dfa.DFAState in project antlr4 by tunnelvisionlabs.

the class LexerATNSimulator method matchATN.

protected int matchATN(@NotNull CharStream input) {
    ATNState startState = atn.modeToStartState.get(mode);
    if (debug) {
        System.out.format(Locale.getDefault(), "matchATN mode %d start: %s\n", mode, startState);
    }
    int old_mode = mode;
    ATNConfigSet s0_closure = computeStartState(input, startState);
    boolean suppressEdge = s0_closure.hasSemanticContext();
    if (suppressEdge) {
        s0_closure.clearExplicitSemanticContext();
    }
    DFAState next = addDFAState(s0_closure);
    if (!suppressEdge) {
        if (!atn.modeToDFA[mode].s0.compareAndSet(null, next)) {
            next = atn.modeToDFA[mode].s0.get();
        }
    }
    int predict = execATN(input, next);
    if (debug) {
        System.out.format(Locale.getDefault(), "DFA after matchATN: %s\n", atn.modeToDFA[old_mode].toLexerString());
    }
    return predict;
}

Example 33 with DFAState

use of org.antlr.v4.runtime.dfa.DFAState in project antlr4 by tunnelvisionlabs.

the class LexerATNSimulator method addDFAEdge.

@NotNull
protected DFAState addDFAEdge(@NotNull DFAState from, int t, @NotNull ATNConfigSet q) {
    /* leading to this call, ATNConfigSet.hasSemanticContext is used as a
		 * marker indicating dynamic predicate evaluation makes this edge
		 * dependent on the specific input sequence, so the static edge in the
		 * DFA should be omitted. The target DFAState is still created since
		 * execATN has the ability to resynchronize with the DFA state cache
		 * following the predicate evaluation step.
		 *
		 * TJP notes: next time through the DFA, we see a pred again and eval.
		 * If that gets us to a previously created (but dangling) DFA
		 * state, we can continue in pure DFA mode from there.
		 */
    boolean suppressEdge = q.hasSemanticContext();
    if (suppressEdge) {
        q.clearExplicitSemanticContext();
    }
    @NotNull DFAState to = addDFAState(q);
    if (suppressEdge) {
        return to;
    }
    addDFAEdge(from, t, to);
    return to;
}

Example 34 with DFAState

use of org.antlr.v4.runtime.dfa.DFAState in project antlr4 by tunnelvisionlabs.

the class ProfilingATNSimulator method getExistingTargetState.

@Override
protected DFAState getExistingTargetState(DFAState previousD, int t) {
    // this method is called after each time the input position advances
    if (currentState.useContext) {
        _llStopIndex = _input.index();
    } else {
        _sllStopIndex = _input.index();
    }
    DFAState existingTargetState = super.getExistingTargetState(previousD, t);
    if (existingTargetState != null) {
        // this method is directly called by execDFA; must construct a SimulatorState
        // to represent the current state for this case
        currentState = new SimulatorState(currentState.outerContext, existingTargetState, currentState.useContext, currentState.remainingOuterContext);
        if (currentState.useContext) {
            decisions[currentDecision].LL_DFATransitions++;
        } else {
            // count only if we transition over a DFA state
            decisions[currentDecision].SLL_DFATransitions++;
        }
        if (existingTargetState == ERROR) {
            SimulatorState state = new SimulatorState(currentState.outerContext, previousD, currentState.useContext, currentState.remainingOuterContext);
            decisions[currentDecision].errors.add(new ErrorInfo(currentDecision, state, _input, _startIndex, _input.index()));
        }
    }
    return existingTargetState;
}