protected internal virtual void PerformGrammarAnalysis(CodeGenerator generator,
Grammar grammar)
{
// Build NFAs from the grammar AST
grammar.BuildNFA();
// Create the DFA predictors for each decision
grammar.CreateLookaheadDFAs();
}
public void TestFiniteCommonLeftPrefixes()
{
Grammar g = new Grammar(
"lexer grammar t;\n" +
"A : 'a' 'b' | 'a' 'c' | 'd' 'e' ;" );
g.BuildNFA();
g.CreateLookaheadDFAs( false );
DFA dfa = g.GetLookaheadDFA( 1 );
checkPrediction( dfa, "ab", 1 );
checkPrediction( dfa, "ac", 2 );
checkPrediction( dfa, "de", 3 );
checkPrediction( dfa, "q", NFA.INVALID_ALT_NUMBER );
}
public void TestSets()
{
Grammar g = new Grammar(
"lexer grammar t;\n" +
"A : {;}'a'..'z' | ';' | '0'..'9' ;" );
g.BuildNFA();
g.CreateLookaheadDFAs( false );
DFA dfa = g.GetLookaheadDFA( 1 );
checkPrediction( dfa, "a", 1 );
checkPrediction( dfa, "q", 1 );
checkPrediction( dfa, "z", 1 );
checkPrediction( dfa, ";", 2 );
checkPrediction( dfa, "9", 3 );
}
public void TestFiniteCommonLeftPrefixes() /*throws Exception*/
{
Grammar g = new Grammar(
"lexer grammar t;\n" +
"A : 'a' 'b' | 'a' 'c' | 'd' 'e' ;");
g.BuildNFA();
g.CreateLookaheadDFAs(false);
DFA dfa = g.GetLookaheadDFA(1);
checkPrediction(dfa, "ab", 1);
checkPrediction(dfa, "ac", 2);
checkPrediction(dfa, "de", 3);
checkPrediction(dfa, "q", NFA.INVALID_ALT_NUMBER);
}
public void TestSimpleAltCharTest() /*throws Exception*/
{
Grammar g = new Grammar(
"lexer grammar t;\n" +
"A : {;}'a' | 'b' | 'c';");
g.BuildNFA();
g.CreateLookaheadDFAs(false);
DFA dfa = g.GetLookaheadDFA(1);
checkPrediction(dfa, "a", 1);
checkPrediction(dfa, "b", 2);
checkPrediction(dfa, "c", 3);
checkPrediction(dfa, "d", NFA.INVALID_ALT_NUMBER);
}
public void TestSimpleLoops() /*throws Exception*/
{
Grammar g = new Grammar(
"lexer grammar t;\n" +
"A : (DIGIT)+ '.' DIGIT | (DIGIT)+ ;\n" +
"fragment DIGIT : '0'..'9' ;\n");
g.BuildNFA();
g.CreateLookaheadDFAs(false);
DFA dfa = g.GetLookaheadDFA(3);
checkPrediction(dfa, "32", 2);
checkPrediction(dfa, "999.2", 1);
checkPrediction(dfa, ".2", NFA.INVALID_ALT_NUMBER);
}
public void TestSets() /*throws Exception*/
{
Grammar g = new Grammar(
"lexer grammar t;\n" +
"A : {;}'a'..'z' | ';' | '0'..'9' ;");
g.BuildNFA();
g.CreateLookaheadDFAs(false);
DFA dfa = g.GetLookaheadDFA(1);
checkPrediction(dfa, "a", 1);
checkPrediction(dfa, "q", 1);
checkPrediction(dfa, "z", 1);
checkPrediction(dfa, ";", 2);
checkPrediction(dfa, "9", 3);
}
protected internal virtual void PerformGrammarAnalysis( CodeGenerator generator,
Grammar grammar )
{
// Build NFAs from the grammar AST
grammar.BuildNFA();
// Create the DFA predictors for each decision
grammar.CreateLookaheadDFAs();
}
public void TestSimpleAltCharTest()
{
Grammar g = new Grammar(
"lexer grammar t;\n" +
"A : {;}'a' | 'b' | 'c';" );
g.BuildNFA();
g.CreateLookaheadDFAs( false );
DFA dfa = g.GetLookaheadDFA( 1 );
checkPrediction( dfa, "a", 1 );
checkPrediction( dfa, "b", 2 );
checkPrediction( dfa, "c", 3 );
checkPrediction( dfa, "d", NFA.INVALID_ALT_NUMBER );
}
public void TestSimpleLoops()
{
Grammar g = new Grammar(
"lexer grammar t;\n" +
"A : (DIGIT)+ '.' DIGIT | (DIGIT)+ ;\n" +
"fragment DIGIT : '0'..'9' ;\n" );
g.BuildNFA();
g.CreateLookaheadDFAs( false );
DFA dfa = g.GetLookaheadDFA( 3 );
checkPrediction( dfa, "32", 2 );
checkPrediction( dfa, "999.2", 1 );
checkPrediction( dfa, ".2", NFA.INVALID_ALT_NUMBER );
}
