Examples with Grammar org.antlr.v4.tool.Grammar used on opensource projects

Example 66 with Grammar

use of org.antlr.v4.tool.Grammar in project antlr4 by antlr.

the class TestATNParserPrediction method testRecursiveLeftPrefix.

@Test
public void testRecursiveLeftPrefix() throws Exception {
    LexerGrammar lg = new LexerGrammar("lexer grammar L;\n" + "A : 'a' ;\n" + "B : 'b' ;\n" + "C : 'c' ;\n" + "LP : '(' ;\n" + "RP : ')' ;\n" + "INT : '0'..'9'+ ;\n");
    Grammar g = new Grammar("parser grammar T;\n" + "tokens {A,B,C,LP,RP,INT}\n" + "a : e B | e C ;\n" + "e : LP e RP\n" + "  | INT\n" + "  ;");
    int decision = 0;
    checkPredictedAlt(lg, g, decision, "34b", 1);
    checkPredictedAlt(lg, g, decision, "34c", 2);
    checkPredictedAlt(lg, g, decision, "((34))b", 1);
    checkPredictedAlt(lg, g, decision, "((34))c", 2);
    // After matching these inputs for decision, what is DFA after each prediction?
    String[] inputs = { "34b", "34c", "((34))b", "((34))c" };
    String[] dfa = { "s0-INT->s1\n" + "s1-'b'->:s2=>1\n", "s0-INT->s1\n" + "s1-'b'->:s2=>1\n" + "s1-'c'->:s3=>2\n", "s0-'('->s4\n" + "s0-INT->s1\n" + "s1-'b'->:s2=>1\n" + "s1-'c'->:s3=>2\n" + "s4-'('->s5\n" + "s5-INT->s6\n" + "s6-')'->s7\n" + "s7-')'->s1\n", "s0-'('->s4\n" + "s0-INT->s1\n" + "s1-'b'->:s2=>1\n" + "s1-'c'->:s3=>2\n" + "s4-'('->s5\n" + "s5-INT->s6\n" + "s6-')'->s7\n" + "s7-')'->s1\n" };
    checkDFAConstruction(lg, g, decision, inputs, dfa);
}

Example 67 with Grammar

use of org.antlr.v4.tool.Grammar in project antlr4 by antlr.

the class TestATNParserPrediction method testAltsForLRRuleComputation.

@Test
public void testAltsForLRRuleComputation() throws Exception {
    Grammar g = new Grammar("grammar T;\n" + "e : e '*' e\n" + "  | INT\n" + "  | e '+' e\n" + "  | ID\n" + "  ;\n" + "ID : [a-z]+ ;\n" + "INT : [0-9]+ ;\n" + "WS : [ \\r\\t\\n]+ ;");
    Rule e = g.getRule("e");
    assertTrue(e instanceof LeftRecursiveRule);
    LeftRecursiveRule lr = (LeftRecursiveRule) e;
    assertEquals("[0, 2, 4]", Arrays.toString(lr.getPrimaryAlts()));
    assertEquals("[0, 1, 3]", Arrays.toString(lr.getRecursiveOpAlts()));
}

Example 68 with Grammar

use of org.antlr.v4.tool.Grammar in project antlr4 by antlr.

the class TestATNParserPrediction method testAltsForLRRuleComputation2.

@Test
public void testAltsForLRRuleComputation2() throws Exception {
    Grammar g = new Grammar("grammar T;\n" + "e : INT\n" + "  | e '*' e\n" + "  | ID\n" + "  ;\n" + "ID : [a-z]+ ;\n" + "INT : [0-9]+ ;\n" + "WS : [ \\r\\t\\n]+ ;");
    Rule e = g.getRule("e");
    assertTrue(e instanceof LeftRecursiveRule);
    LeftRecursiveRule lr = (LeftRecursiveRule) e;
    assertEquals("[0, 1, 3]", Arrays.toString(lr.getPrimaryAlts()));
    assertEquals("[0, 2]", Arrays.toString(lr.getRecursiveOpAlts()));
}

Example 69 with Grammar

use of org.antlr.v4.tool.Grammar in project antlr4 by antlr.

the class TestATNParserPrediction method testOptionalRuleChasesGlobalFollow.

@Test
public void testOptionalRuleChasesGlobalFollow() throws Exception {
    LexerGrammar lg = new LexerGrammar("lexer grammar L;\n" + "A : 'a' ;\n" + "B : 'b' ;\n" + "C : 'c' ;\n");
    Grammar g = new Grammar("parser grammar T;\n" + "tokens {A,B,C}\n" + "a : x B ;\n" + "b : x C ;\n" + "x : A | ;\n");
    int decision = 0;
    checkPredictedAlt(lg, g, decision, "a", 1);
    checkPredictedAlt(lg, g, decision, "b", 2);
    checkPredictedAlt(lg, g, decision, "c", 2);
    // After matching these inputs for decision, what is DFA after each prediction?
    String[] inputs = { "a", "b", "c", "c" };
    String[] dfa = { "s0-'a'->:s1=>1\n", "s0-'a'->:s1=>1\n" + "s0-'b'->:s2=>2\n", "s0-'a'->:s1=>1\n" + "s0-'b'->:s2=>2\n" + "s0-'c'->:s3=>2\n", "s0-'a'->:s1=>1\n" + "s0-'b'->:s2=>2\n" + "s0-'c'->:s3=>2\n" };
    checkDFAConstruction(lg, g, decision, inputs, dfa);
}

Example 70 with Grammar

use of org.antlr.v4.tool.Grammar in project antlr4 by antlr.

the class TestATNParserPrediction method testRuleRefxory.

@Test
public void testRuleRefxory() throws Exception {
    LexerGrammar lg = new LexerGrammar("lexer grammar L;\n" + "A : 'a' ;\n" + "B : 'b' ;\n" + "C : 'c' ;\n");
    Grammar g = new Grammar("parser grammar T;\n" + "a : x | y ;\n" + "x : A ;\n" + "y : B ;\n");
    int decision = 0;
    checkPredictedAlt(lg, g, decision, "a", 1);
    checkPredictedAlt(lg, g, decision, "b", 2);
    // After matching these inputs for decision, what is DFA after each prediction?
    String[] inputs = { "a", "b", "a" };
    String[] dfa = { "s0-'a'->:s1=>1\n", "s0-'a'->:s1=>1\n" + "s0-'b'->:s2=>2\n", // don't change after it works
    "s0-'a'->:s1=>1\n" + "s0-'b'->:s2=>2\n" };
    checkDFAConstruction(lg, g, decision, inputs, dfa);
}