|
public AddTransition ( |
||
| target | ||
| label | Antlr3.Analysis.Label | |
| return | int | |
/** From list of lookahead sets (one per alt in decision), create
* an LL(1) DFA. One edge per set.
*
* s0-{alt1}->:o=>1
* | \
* | -{alt2}->:o=>2
* |
* ...
*/
public LL1DFA(int decisionNumber, NFAState decisionStartState, LookaheadSet[] altLook)
: base(decisionNumber, decisionStartState)
{
DFAState s0 = NewState();
StartState = s0;
UnreachableAlts.Clear();
for (int alt = 1; alt < altLook.Length; alt++)
{
DFAState acceptAltState = NewState();
acceptAltState.IsAcceptState = true;
SetAcceptState(alt, acceptAltState);
acceptAltState.LookaheadDepth = 1;
acceptAltState.CachedUniquelyPredicatedAlt = alt;
Label e = GetLabelForSet(altLook[alt].TokenTypeSet);
s0.AddTransition(acceptAltState, e);
}
}
/** From list of lookahead sets (one per alt in decision), create
* an LL(1) DFA. One edge per set.
*
* s0-{alt1}->:o=>1
* | \
* | -{alt2}->:o=>2
* |
* ...
*/
public LL1DFA(int decisionNumber, NFAState decisionStartState, LookaheadSet[] altLook)
{
DFAState s0 = NewState();
startState = s0;
nfa = decisionStartState.nfa;
NumberOfAlts = nfa.grammar.GetNumberOfAltsForDecisionNFA(decisionStartState);
this.decisionNumber = decisionNumber;
this.NFADecisionStartState = decisionStartState;
InitAltRelatedInfo();
UnreachableAlts = null;
for (int alt = 1; alt < altLook.Length; alt++)
{
DFAState acceptAltState = NewState();
acceptAltState.acceptState = true;
SetAcceptState(alt, acceptAltState);
acceptAltState.LookaheadDepth = 1;
acceptAltState.cachedUniquelyPredicatedAlt = alt;
Label e = GetLabelForSet(altLook[alt].tokenTypeSet);
s0.AddTransition(acceptAltState, e);
}
}
/** From a set of edgeset->list-of-alts mappings, create a DFA
* that uses syn preds for all |list-of-alts|>1.
*/
public LL1DFA(int decisionNumber,
NFAState decisionStartState,
MultiMap <IntervalSet, int> edgeMap)
{
DFAState s0 = NewState();
startState = s0;
nfa = decisionStartState.nfa;
NumberOfAlts = nfa.grammar.GetNumberOfAltsForDecisionNFA(decisionStartState);
this.decisionNumber = decisionNumber;
this.NFADecisionStartState = decisionStartState;
InitAltRelatedInfo();
UnreachableAlts = null;
foreach (var edgeVar in edgeMap)
{
IntervalSet edge = edgeVar.Key;
IList <int> alts = edgeVar.Value;
alts = alts.OrderBy(i => i).ToList();
//Collections.sort( alts ); // make sure alts are attempted in order
//[email protected](edge+" -> "+alts);
DFAState s = NewState();
s.LookaheadDepth = 1;
Label e = GetLabelForSet(edge);
s0.AddTransition(s, e);
if (alts.Count == 1)
{
s.acceptState = true;
int alt = alts[0];
SetAcceptState(alt, s);
s.cachedUniquelyPredicatedAlt = alt;
}
else
{
// resolve with syntactic predicates. Add edges from
// state s that test predicates.
s.IsResolvedWithPredicates = true;
for (int i = 0; i < alts.Count; i++)
{
int alt = (int)alts[i];
s.cachedUniquelyPredicatedAlt = NFA.INVALID_ALT_NUMBER;
DFAState predDFATarget = GetAcceptState(alt);
if (predDFATarget == null)
{
predDFATarget = NewState(); // create if not there.
predDFATarget.acceptState = true;
predDFATarget.cachedUniquelyPredicatedAlt = alt;
SetAcceptState(alt, predDFATarget);
}
// add a transition to pred target from d
/*
* int walkAlt =
* decisionStartState.translateDisplayAltToWalkAlt(alt);
* NFAState altLeftEdge = nfa.grammar.getNFAStateForAltOfDecision(decisionStartState, walkAlt);
* NFAState altStartState = (NFAState)altLeftEdge.transition[0].target;
* SemanticContext ctx = nfa.grammar.ll1Analyzer.getPredicates(altStartState);
* [email protected]("sem ctx = "+ctx);
* if ( ctx == null ) {
* ctx = new SemanticContext.TruePredicate();
* }
* s.addTransition(predDFATarget, new Label(ctx));
*/
SemanticContext.Predicate synpred =
GetSynPredForAlt(decisionStartState, alt);
if (synpred == null)
{
synpred = new SemanticContext.TruePredicate();
}
s.AddTransition(predDFATarget, new PredicateLabel(synpred));
}
}
}
//[email protected]("dfa for preds=\n"+this);
}