本文整理汇总了Java中org.antlr.v4.runtime.atn.ATNState.BLOCK_START属性的典型用法代码示例。如果您正苦于以下问题：Java ATNState.BLOCK_START属性的具体用法？Java ATNState.BLOCK_START怎么用？Java ATNState.BLOCK_START使用的例子？那么恭喜您, 这里精选的属性代码示例或许可以为您提供帮助。您也可以进一步了解该属性所在类org.antlr.v4.runtime.atn.ATNState的用法示例。
在下文中一共展示了ATNState.BLOCK_START属性的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Java代码示例。
示例1: visitDecisionState
/** Override this method so that we can record which alternative
* was taken at each decision point. For non-left recursive rules,
* it's simple. Set decisionStatesThatSetOuterAltNumInContext
* indicates which decision states should set the outer alternative number.
*
* <p>Left recursive rules are much more complicated to deal with:
* there is typically a decision for the primary alternatives and a
* decision to choose between the recursive operator alternatives.
* For example, the following left recursive rule has two primary and 2
* recursive alternatives.</p>
*
e : e '*' e
| '-' INT
| e '+' e
| ID
;
* <p>ANTLR rewrites that rule to be</p>
e[int precedence]
: ('-' INT | ID)
( {...}? '*' e[5]
| {...}? '+' e[3]
)*
;
*
* <p>So, there are two decisions associated with picking the outermost alt.
* This complicates our tracking significantly. The outermost alternative number
* is a function of the decision (ATN state) within a left recursive rule and the
* predicted alternative coming back from adaptivePredict().
*
* We use stateToAltsMap as a cache to avoid expensive calls to
* getRecursiveOpAlts().
*/
@Override
protected int visitDecisionState(DecisionState p) {
int predictedAlt = super.visitDecisionState(p);
if( p.getNumberOfTransitions() > 1) {
// System.out.println("decision "+p.decision+": "+predictedAlt);
if( p.decision == this.overrideDecision &&
this._input.index() == this.overrideDecisionInputIndex )
{
overrideDecisionRoot = (GrammarInterpreterRuleContext)getContext();
}
}
GrammarInterpreterRuleContext ctx = (GrammarInterpreterRuleContext)_ctx;
if ( decisionStatesThatSetOuterAltNumInContext.get(p.stateNumber) ) {
ctx.outerAltNum = predictedAlt;
Rule r = g.getRule(p.ruleIndex);
if ( atn.ruleToStartState[r.index].isLeftRecursiveRule ) {
int[] alts = stateToAltsMap[p.stateNumber];
LeftRecursiveRule lr = (LeftRecursiveRule) g.getRule(p.ruleIndex);
if (p.getStateType() == ATNState.BLOCK_START) {
if ( alts==null ) {
alts = lr.getPrimaryAlts();
stateToAltsMap[p.stateNumber] = alts; // cache it
}
}
else if ( p.getStateType() == ATNState.STAR_BLOCK_START ) {
if ( alts==null ) {
alts = lr.getRecursiveOpAlts();
stateToAltsMap[p.stateNumber] = alts; // cache it
}
}
ctx.outerAltNum = alts[predictedAlt];
}
}
return predictedAlt;
}