forked from jasder/antlr
validate FullContextParsing tests
This commit is contained in:
ericvergnaud
parent
e39ac5a197
commit
31812721c8
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@ -1,7 +1,5 @@
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package org.antlr.v4.test.rt.gen;
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import static org.junit.Assert.assertEquals;
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import java.io.File;
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import java.io.FileNotFoundException;
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import java.io.FileOutputStream;
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@ -846,11 +844,12 @@ public class Generator {
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private TestFile buildFullContextParsing() throws Exception {
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TestFile file = new TestFile("FullContextParsing");
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file.addParserTest(input, "AmbigYieldsCtxSensitiveDFA", "T", "s", "abc",
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TestMethod tm = file.addParserTest(input, "AmbigYieldsCtxSensitiveDFA", "T", "s", "abc",
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"Decision 0:\n" +
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"s0-ID->:s1^=>1\n",
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"line 1:0 reportAttemptingFullContext d=0 (s), input='abc'\n");
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file.addParserTestsWithErrors(input, "CtxSensitiveDFA", "T", "s",
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tm.debug = true;
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tm = file.addParserTestsWithErrors(input, "CtxSensitiveDFA", "T", "s",
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"$ 34 abc",
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"Decision 1:\n" +
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"s0-INT->s1\n" +
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@ -863,7 +862,8 @@ public class Generator {
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"s1-ID->:s2^=>1\n",
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"line 1:5 reportAttemptingFullContext d=1 (e), input='34abc'\n" +
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"line 1:5 reportContextSensitivity d=1 (e), input='34abc'\n");
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file.addParserTest(input, "CtxSensitiveDFATwoDiffInput", "T", "s",
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tm.debug = true;
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tm = file.addParserTest(input, "CtxSensitiveDFATwoDiffInput", "T", "s",
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"$ 34 abc @ 34 abc",
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"Decision 2:\n" +
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"s0-INT->s1\n" +
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@ -872,14 +872,16 @@ public class Generator {
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"line 1:2 reportContextSensitivity d=2 (e), input='34'\n" +
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"line 1:14 reportAttemptingFullContext d=2 (e), input='34abc'\n" +
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"line 1:14 reportContextSensitivity d=2 (e), input='34abc'\n");
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file.addParserTest(input, "SLLSeesEOFInLLGrammar", "T", "s",
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tm.debug = true;
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tm = file.addParserTest(input, "SLLSeesEOFInLLGrammar", "T", "s",
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"34 abc",
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"Decision 0:\n" +
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"s0-INT->s1\n" +
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"s1-ID->:s2^=>1\n",
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"line 1:3 reportAttemptingFullContext d=0 (e), input='34abc'\n" +
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"line 1:0 reportContextSensitivity d=0 (e), input='34'\n");
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file.addParserTestsWithErrors(input, "FullContextIF_THEN_ELSEParse", "T", "s",
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tm.debug = true;
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tm = file.addParserTestsWithErrors(input, "FullContextIF_THEN_ELSEParse", "T", "s",
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"{ if x then return }",
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"Decision 1:\n" +
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"s0-'}'->:s1=>2\n",
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@ -923,19 +925,22 @@ public class Generator {
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"line 1:19 reportContextSensitivity d=1 (stat), input='else'\n" +
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"line 2:27 reportAttemptingFullContext d=1 (stat), input='else'\n" +
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"line 2:36 reportAmbiguity d=1 (stat): ambigAlts={1, 2}, input='elsefoo}'\n");
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file.addParserTest(input, "LoopsSimulateTailRecursion", "T", "prog",
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tm.debug = true;
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tm = file.addParserTest(input, "LoopsSimulateTailRecursion", "T", "prog",
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"a(i)<-x",
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"pass: a(i)<-x\n",
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"line 1:3 reportAttemptingFullContext d=3 (expr_primary), input='a(i)'\n" +
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"line 1:7 reportAmbiguity d=3 (expr_primary): ambigAlts={2, 3}, input='a(i)<-x'\n");
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file.addParserTest(input, "AmbiguityNoLoop", "T", "prog",
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tm.debug = true;
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tm = file.addParserTest(input, "AmbiguityNoLoop", "T", "prog",
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"a@",
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"alt 1\n",
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"line 1:2 reportAttemptingFullContext d=0 (prog), input='a@'\n" +
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"line 1:2 reportAmbiguity d=0 (prog): ambigAlts={1, 2}, input='a@'\n" +
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"line 1:2 reportAttemptingFullContext d=1 (expr), input='a@'\n" +
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"line 1:2 reportContextSensitivity d=1 (expr), input='a@'\n");
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file.addParserTestsWithErrors(input, "ExprAmbiguity", "T", "s",
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tm.debug = true;
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tm = file.addParserTestsWithErrors(input, "ExprAmbiguity", "T", "s",
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"a+b",
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"(expr a + (expr b))\n",
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"line 1:1 reportAttemptingFullContext d=1 (expr), input='+'\n" +
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@ -946,6 +951,7 @@ public class Generator {
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"line 1:2 reportContextSensitivity d=1 (expr), input='+b'\n" +
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"line 1:3 reportAttemptingFullContext d=1 (expr), input='*'\n" +
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"line 1:5 reportAmbiguity d=1 (expr): ambigAlts={1, 2}, input='*c'\n");
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tm.debug = true;
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return file;
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}
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@ -12,6 +12,7 @@ public abstract class TestMethod {
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public String input;
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public String expectedOutput;
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public String expectedErrors;
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public boolean debug = false;
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protected TestMethod(String name, String grammarName, String input,
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String expectedOutput, String expectedErrors, Integer index) {
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@ -58,7 +58,7 @@ public void test<test.name>() throws Exception {
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};separator="\n", wrap, anchor>
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String grammar = <test.grammar.lines:{ line | "<line>};separator="\\n\" +\n", wrap, anchor>";
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<test.afterGrammar>
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String found = execParser("<test.grammar.grammarName>.g4", grammar, "<test.grammar.grammarName><if(!test.slaveIsLexer)>Parser<endif>", "<if(test.slaveIsLexer)><first(test.slaveGrammars).grammarName><else><test.grammar.grammarName>Lexer<endif>", "<test.startRule>", "<test.input>", false);
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String found = execParser("<test.grammar.grammarName>.g4", grammar, "<test.grammar.grammarName><if(!test.slaveIsLexer)>Parser<endif>", "<if(test.slaveIsLexer)><first(test.slaveGrammars).grammarName><else><test.grammar.grammarName>Lexer<endif>", "<test.startRule>", "<test.input>", <test.debug>);
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assertEquals("<test.expectedOutput>", found);
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<if(test.expectedErrors)>
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assertEquals("<test.expectedErrors>", this.stderrDuringParse);
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@ -76,7 +76,7 @@ CompositeParserTestMethod(test) ::= <<
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AbstractParserTestMethod(test) ::= <<
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String test<test.name>(String input) throws Exception {
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String grammar = <test.grammar.lines:{ line | "<line>};separator="\\n\" +\n", wrap, anchor>";
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return execParser("<test.grammar.grammarName>.g4", grammar, "<test.grammar.grammarName>Parser", "<test.grammar.grammarName>Lexer", "<test.startRule>", input, false);
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return execParser("<test.grammar.grammarName>.g4", grammar, "<test.grammar.grammarName>Parser", "<test.grammar.grammarName>Lexer", "<test.startRule>", input, <test.debug>);
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}
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>>
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@ -12,7 +12,7 @@ public class TestFullContextParsing extends BaseTest {
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" : ID | ID {} ;\n" +
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"ID : 'a'..'z'+;\n" +
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"WS : (' '|'\\t'|'\\n')+ -> skip ;";
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String found = execParser("T.g4", grammar, "TParser", "TLexer", "s", "abc", false);
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String found = execParser("T.g4", grammar, "TParser", "TLexer", "s", "abc", true);
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assertEquals("Decision 0:\ns0-ID->:s1^=>1\n", found);
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assertEquals("line 1:0 reportAttemptingFullContext d=0 (s), input='abc'\n", this.stderrDuringParse);
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}
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@ -27,7 +27,7 @@ public class TestFullContextParsing extends BaseTest {
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"ID : 'a'..'z'+ ;\n" +
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"INT : '0'..'9'+ ;\n" +
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"WS : (' '|'\\t'|'\\n')+ -> skip ;";
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return execParser("T.g4", grammar, "TParser", "TLexer", "s", input, false);
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return execParser("T.g4", grammar, "TParser", "TLexer", "s", input, true);
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}
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@Test
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@ -55,7 +55,7 @@ public class TestFullContextParsing extends BaseTest {
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"ID : 'a'..'z'+ ;\n" +
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"INT : '0'..'9'+ ;\n" +
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"WS : (' '|'\\t'|'\\n')+ -> skip ;";
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String found = execParser("T.g4", grammar, "TParser", "TLexer", "s", "$ 34 abc @ 34 abc", false);
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String found = execParser("T.g4", grammar, "TParser", "TLexer", "s", "$ 34 abc @ 34 abc", true);
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assertEquals("Decision 2:\ns0-INT->s1\ns1-ID->:s2^=>1\n", found);
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assertEquals("line 1:5 reportAttemptingFullContext d=2 (e), input='34abc'\nline 1:2 reportContextSensitivity d=2 (e), input='34'\nline 1:14 reportAttemptingFullContext d=2 (e), input='34abc'\nline 1:14 reportContextSensitivity d=2 (e), input='34abc'\n", this.stderrDuringParse);
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}
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@ -71,7 +71,7 @@ public class TestFullContextParsing extends BaseTest {
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"ID : 'a'..'z'+ ;\n" +
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"INT : '0'..'9'+ ;\n" +
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"WS : (' '|'\\t'|'\\n')+ -> skip ;";
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String found = execParser("T.g4", grammar, "TParser", "TLexer", "s", "34 abc", false);
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String found = execParser("T.g4", grammar, "TParser", "TLexer", "s", "34 abc", true);
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assertEquals("Decision 0:\ns0-INT->s1\ns1-ID->:s2^=>1\n", found);
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assertEquals("line 1:3 reportAttemptingFullContext d=0 (e), input='34abc'\nline 1:0 reportContextSensitivity d=0 (e), input='34'\n", this.stderrDuringParse);
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}
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@ -87,7 +87,7 @@ public class TestFullContextParsing extends BaseTest {
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" ;\n" +
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"ID : 'a'..'z'+ ;\n" +
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"WS : (' '|'\\t'|'\\n')+ -> skip ;";
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return execParser("T.g4", grammar, "TParser", "TLexer", "s", input, false);
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return execParser("T.g4", grammar, "TParser", "TLexer", "s", input, true);
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}
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@Test
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@ -149,7 +149,7 @@ public class TestFullContextParsing extends BaseTest {
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" | ID\n" +
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" ;\n" +
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"ID : [a-z]+ ;";
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String found = execParser("T.g4", grammar, "TParser", "TLexer", "prog", "a(i)<-x", false);
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String found = execParser("T.g4", grammar, "TParser", "TLexer", "prog", "a(i)<-x", true);
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assertEquals("pass: a(i)<-x\n", found);
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assertEquals("line 1:3 reportAttemptingFullContext d=3 (expr_primary), input='a(i)'\nline 1:7 reportAmbiguity d=3 (expr_primary): ambigAlts={2, 3}, input='a(i)<-x'\n", this.stderrDuringParse);
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}
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@ -168,7 +168,7 @@ public class TestFullContextParsing extends BaseTest {
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" ;\n" +
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"ID : [a-z]+ ;\n" +
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"WS : [ \\r\\n\\t]+ -> skip ;";
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String found = execParser("T.g4", grammar, "TParser", "TLexer", "prog", "a@", false);
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String found = execParser("T.g4", grammar, "TParser", "TLexer", "prog", "a@", true);
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assertEquals("alt 1\n", found);
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assertEquals("line 1:2 reportAttemptingFullContext d=0 (prog), input='a@'\nline 1:2 reportAmbiguity d=0 (prog): ambigAlts={1, 2}, input='a@'\nline 1:2 reportAttemptingFullContext d=1 (expr), input='a@'\nline 1:2 reportContextSensitivity d=1 (expr), input='a@'\n", this.stderrDuringParse);
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}
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@ -187,7 +187,7 @@ public class TestFullContextParsing extends BaseTest {
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" ;\n" +
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"ID : [a-zA-Z]+ ;\n" +
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"WS : [ \\r\\n\\t]+ -> skip ;";
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return execParser("T.g4", grammar, "TParser", "TLexer", "s", input, false);
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return execParser("T.g4", grammar, "TParser", "TLexer", "s", input, true);
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}
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@Test
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@ -1,356 +0,0 @@
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/*
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* [The "BSD license"]
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* Copyright (c) 2012 Terence Parr
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* Copyright (c) 2012 Sam Harwell
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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package org.antlr.v4.test.tool;
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import org.junit.Test;
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import static org.junit.Assert.assertEquals;
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/*
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cover these cases:
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dead end
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single alt
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single alt + preds
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conflict
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conflict + preds
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*/
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public class TestFullContextParsing extends BaseTest {
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@Test public void testAmbigYieldsCtxSensitiveDFA() {
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String grammar =
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"grammar T;\n"+
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"s" +
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"@after {dumpDFA();}\n" +
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" : ID | ID {;} ;\n" +
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"ID : 'a'..'z'+ ;\n"+
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"WS : (' '|'\\t'|'\\n')+ -> skip ;\n";
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String result = execParser("T.g4", grammar, "TParser", "TLexer", "s",
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"abc", true);
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String expecting =
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"Decision 0:\n" +
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"s0-ID->:s1^=>1\n"; // ctx sensitive
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assertEquals(expecting, result);
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assertEquals("line 1:0 reportAttemptingFullContext d=0 (s), input='abc'\n",
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this.stderrDuringParse);
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}
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public String testCtxSensitiveDFA(String input) {
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String grammar =
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"grammar T;\n"+
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"s @after {dumpDFA();}\n" +
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" : '$' a | '@' b ;\n" +
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"a : e ID ;\n" +
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"b : e INT ID ;\n" +
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"e : INT | ;\n" +
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"ID : 'a'..'z'+ ;\n"+
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"INT : '0'..'9'+ ;\n"+
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"WS : (' '|'\\t'|'\\n')+ -> skip ;\n";
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return execParser("T.g4", grammar, "TParser", "TLexer", "s", input, true);
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}
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@Test
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public void testCtxSensitiveDFA1() {
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String result = testCtxSensitiveDFA("$ 34 abc");
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String expecting =
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"Decision 1:\n" +
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"s0-INT->s1\n" +
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"s1-ID->:s2^=>1\n";
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assertEquals(expecting, result);
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assertEquals("line 1:5 reportAttemptingFullContext d=1 (e), input='34abc'\n" +
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"line 1:2 reportContextSensitivity d=1 (e), input='34'\n",
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this.stderrDuringParse);
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}
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@Test
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public void testCtxSensitiveDFA2() {
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String result = testCtxSensitiveDFA("@ 34 abc");
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String expecting =
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"Decision 1:\n" +
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"s0-INT->s1\n" +
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"s1-ID->:s2^=>1\n";
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assertEquals(expecting, result);
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assertEquals("line 1:5 reportAttemptingFullContext d=1 (e), input='34abc'\n" +
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"line 1:5 reportContextSensitivity d=1 (e), input='34abc'\n",
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this.stderrDuringParse);
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}
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@Test public void testCtxSensitiveDFATwoDiffInput() {
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String grammar =
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"grammar T;\n"+
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"s @after {dumpDFA();}\n" +
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" : ('$' a | '@' b)+ ;\n" +
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"a : e ID ;\n" +
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"b : e INT ID ;\n" +
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"e : INT | ;\n" +
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"ID : 'a'..'z'+ ;\n"+
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"INT : '0'..'9'+ ;\n"+
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"WS : (' '|'\\t'|'\\n')+ -> skip ;\n";
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String result = execParser("T.g4", grammar, "TParser", "TLexer", "s",
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"$ 34 abc @ 34 abc", true);
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String expecting =
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"Decision 2:\n" +
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"s0-INT->s1\n" +
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"s1-ID->:s2^=>1\n";
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assertEquals(expecting, result);
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assertEquals("line 1:5 reportAttemptingFullContext d=2 (e), input='34abc'\n" +
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"line 1:2 reportContextSensitivity d=2 (e), input='34'\n" +
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"line 1:14 reportAttemptingFullContext d=2 (e), input='34abc'\n" +
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"line 1:14 reportContextSensitivity d=2 (e), input='34abc'\n",
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this.stderrDuringParse);
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}
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@Test
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public void testSLLSeesEOFInLLGrammar() {
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String grammar =
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"grammar T;\n"+
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"s @after {dumpDFA();}\n" +
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" : a ;\n" +
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"a : e ID ;\n" +
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"b : e INT ID ;\n" +
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"e : INT | ;\n" +
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"ID : 'a'..'z'+ ;\n"+
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"INT : '0'..'9'+ ;\n"+
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"WS : (' '|'\\t'|'\\n')+ -> skip ;\n";
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String result = execParser("T.g4", grammar, "TParser", "TLexer", "s",
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"34 abc", true);
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String expecting =
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"Decision 0:\n" +
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"s0-INT->s1\n" +
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"s1-ID->:s2^=>1\n"; // Must point at accept state
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assertEquals(expecting, result);
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assertEquals("line 1:3 reportAttemptingFullContext d=0 (e), input='34abc'\n" +
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"line 1:0 reportContextSensitivity d=0 (e), input='34'\n",
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this.stderrDuringParse);
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}
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@Test public void testFullContextIF_THEN_ELSEParse() {
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String grammar =
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"grammar T;\n"+
|
||||
"s" +
|
||||
"@init {_interp.setPredictionMode(PredictionMode.LL_EXACT_AMBIG_DETECTION);}\n" +
|
||||
"@after {dumpDFA();}\n" +
|
||||
" : '{' stat* '}'" +
|
||||
" ;\n" +
|
||||
"stat: 'if' ID 'then' stat ('else' ID)?\n" +
|
||||
" | 'return'\n" +
|
||||
" ;" +
|
||||
"ID : 'a'..'z'+ ;\n"+
|
||||
"WS : (' '|'\\t'|'\\n')+ -> skip ;\n";
|
||||
String input = "{ if x then return }";
|
||||
String result = execParser("T.g4", grammar, "TParser", "TLexer", "s",
|
||||
input, true);
|
||||
String expecting =
|
||||
"Decision 1:\n" +
|
||||
"s0-'}'->:s1=>2\n";
|
||||
assertEquals(expecting, result);
|
||||
assertEquals(null, this.stderrDuringParse);
|
||||
|
||||
input = "{ if x then return else foo }";
|
||||
result = execParser("T.g4", grammar, "TParser", "TLexer", "s",
|
||||
input, true);
|
||||
expecting =
|
||||
"Decision 1:\n" +
|
||||
"s0-'else'->:s1^=>1\n";
|
||||
assertEquals(expecting, result);
|
||||
// Technically, this input sequence is not ambiguous because else
|
||||
// uniquely predicts going into the optional subrule. else cannot
|
||||
// be matched by exiting stat since that would only match '}' or
|
||||
// the start of a stat. But, we are using the theory that
|
||||
// SLL(1)=LL(1) and so we are avoiding full context parsing
|
||||
// by declaring all else clause parsing to be ambiguous.
|
||||
assertEquals("line 1:19 reportAttemptingFullContext d=1 (stat), input='else'\n" +
|
||||
"line 1:19 reportContextSensitivity d=1 (stat), input='else'\n",
|
||||
this.stderrDuringParse);
|
||||
|
||||
input =
|
||||
"{ if x then if y then return else foo }";
|
||||
result = execParser("T.g4", grammar, "TParser", "TLexer", "s",
|
||||
input, true);
|
||||
expecting =
|
||||
"Decision 1:\n" +
|
||||
"s0-'}'->:s2=>2\n" +
|
||||
"s0-'else'->:s1^=>1\n";
|
||||
assertEquals(expecting, result);
|
||||
assertEquals("line 1:29 reportAttemptingFullContext d=1 (stat), input='else'\n" +
|
||||
"line 1:38 reportAmbiguity d=1 (stat): ambigAlts={1, 2}, input='elsefoo}'\n",
|
||||
this.stderrDuringParse);
|
||||
|
||||
// should not be ambiguous because the second 'else bar' clearly
|
||||
// indicates that the first else should match to the innermost if.
|
||||
// LL_EXACT_AMBIG_DETECTION makes us keep going to resolve
|
||||
|
||||
input =
|
||||
"{ if x then if y then return else foo else bar }";
|
||||
result = execParser("T.g4", grammar, "TParser", "TLexer", "s",
|
||||
input, true);
|
||||
expecting =
|
||||
"Decision 1:\n" +
|
||||
"s0-'else'->:s1^=>1\n";
|
||||
assertEquals(expecting, result);
|
||||
assertEquals("line 1:29 reportAttemptingFullContext d=1 (stat), input='else'\n" +
|
||||
"line 1:38 reportContextSensitivity d=1 (stat), input='elsefooelse'\n" +
|
||||
"line 1:38 reportAttemptingFullContext d=1 (stat), input='else'\n" +
|
||||
"line 1:38 reportContextSensitivity d=1 (stat), input='else'\n",
|
||||
this.stderrDuringParse);
|
||||
|
||||
input =
|
||||
"{ if x then return else foo\n" +
|
||||
"if x then if y then return else foo }";
|
||||
result = execParser("T.g4", grammar, "TParser", "TLexer", "s",
|
||||
input, true);
|
||||
expecting =
|
||||
"Decision 1:\n" +
|
||||
"s0-'}'->:s2=>2\n" +
|
||||
"s0-'else'->:s1^=>1\n";
|
||||
assertEquals(expecting, result);
|
||||
assertEquals("line 1:19 reportAttemptingFullContext d=1 (stat), input='else'\n" +
|
||||
"line 1:19 reportContextSensitivity d=1 (stat), input='else'\n" +
|
||||
"line 2:27 reportAttemptingFullContext d=1 (stat), input='else'\n" +
|
||||
"line 2:36 reportAmbiguity d=1 (stat): ambigAlts={1, 2}, input='elsefoo}'\n",
|
||||
this.stderrDuringParse);
|
||||
|
||||
input =
|
||||
"{ if x then return else foo\n" +
|
||||
"if x then if y then return else foo }";
|
||||
result = execParser("T.g4", grammar, "TParser", "TLexer", "s",
|
||||
input, true);
|
||||
expecting =
|
||||
"Decision 1:\n" +
|
||||
"s0-'}'->:s2=>2\n" +
|
||||
"s0-'else'->:s1^=>1\n";
|
||||
assertEquals(expecting, result);
|
||||
assertEquals("line 1:19 reportAttemptingFullContext d=1 (stat), input='else'\n" +
|
||||
"line 1:19 reportContextSensitivity d=1 (stat), input='else'\n" +
|
||||
"line 2:27 reportAttemptingFullContext d=1 (stat), input='else'\n" +
|
||||
"line 2:36 reportAmbiguity d=1 (stat): ambigAlts={1, 2}, input='elsefoo}'\n",
|
||||
this.stderrDuringParse);
|
||||
}
|
||||
|
||||
/**
|
||||
* Tests predictions for the following case involving closures.
|
||||
* http://www.antlr.org/wiki/display/~admin/2011/12/29/Flaw+in+ANTLR+v3+LL(*)+analysis+algorithm
|
||||
*/
|
||||
@Test
|
||||
public void testLoopsSimulateTailRecursion() throws Exception {
|
||||
String grammar =
|
||||
"grammar T;\n" +
|
||||
"prog\n" +
|
||||
"@init {_interp.setPredictionMode(PredictionMode.LL_EXACT_AMBIG_DETECTION);}\n" +
|
||||
" : expr_or_assign*;\n" +
|
||||
"expr_or_assign\n" +
|
||||
" : expr '++' {System.out.println(\"fail.\");}\n" +
|
||||
" | expr {System.out.println(\"pass: \"+$expr.text);}\n" +
|
||||
" ;\n" +
|
||||
"expr: expr_primary ('<-' ID)? ;\n" +
|
||||
"expr_primary\n" +
|
||||
" : '(' ID ')'\n" +
|
||||
" | ID '(' ID ')'\n" +
|
||||
" | ID\n" +
|
||||
" ;\n" +
|
||||
"ID : [a-z]+ ;\n" +
|
||||
"";
|
||||
|
||||
String found = execParser("T.g4", grammar, "TParser", "TLexer", "prog", "a(i)<-x", true);
|
||||
assertEquals("pass: a(i)<-x\n", found);
|
||||
|
||||
String expecting =
|
||||
"line 1:3 reportAttemptingFullContext d=3 (expr_primary), input='a(i)'\n" +
|
||||
"line 1:7 reportAmbiguity d=3 (expr_primary): ambigAlts={2, 3}, input='a(i)<-x'\n";
|
||||
assertEquals(expecting, this.stderrDuringParse);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void testAmbiguityNoLoop() throws Exception {
|
||||
// simpler version of testLoopsSimulateTailRecursion, no loops
|
||||
String grammar =
|
||||
"grammar T;\n" +
|
||||
"prog\n" +
|
||||
"@init {_interp.setPredictionMode(PredictionMode.LL_EXACT_AMBIG_DETECTION);}\n" +
|
||||
" : expr expr {System.out.println(\"alt 1\");}\n" +
|
||||
" | expr\n" +
|
||||
" ;\n" +
|
||||
"expr: '@'\n" +
|
||||
" | ID '@'\n" +
|
||||
" | ID\n" +
|
||||
" ;\n" +
|
||||
"ID : [a-z]+ ;\n" +
|
||||
"WS : [ \\r\\n\\t]+ -> skip ;\n";
|
||||
|
||||
String found = execParser("T.g4", grammar, "TParser", "TLexer", "prog", "a@", true);
|
||||
assertEquals("alt 1\n", found);
|
||||
|
||||
String expecting =
|
||||
"line 1:2 reportAttemptingFullContext d=0 (prog), input='a@'\n" +
|
||||
"line 1:2 reportAmbiguity d=0 (prog): ambigAlts={1, 2}, input='a@'\n" +
|
||||
"line 1:2 reportAttemptingFullContext d=1 (expr), input='a@'\n" +
|
||||
"line 1:2 reportContextSensitivity d=1 (expr), input='a@'\n";
|
||||
assertEquals(expecting, this.stderrDuringParse);
|
||||
}
|
||||
|
||||
@Test
|
||||
public void testExprAmbiguity() throws Exception {
|
||||
// translated left-recursive expr rule to test ambig detection
|
||||
String grammar =
|
||||
"grammar T;\n" +
|
||||
"s\n" +
|
||||
"@init {_interp.setPredictionMode(PredictionMode.LL_EXACT_AMBIG_DETECTION);}\n" +
|
||||
" : expr[0] {System.out.println($expr.ctx.toStringTree(this));} ;\n" +
|
||||
"\n" +
|
||||
"expr[int _p]\n" +
|
||||
" : ID\n" +
|
||||
" ( {5 >= $_p}? '*' expr[6]\n" +
|
||||
" | {4 >= $_p}? '+' expr[5]\n" +
|
||||
" )*\n" +
|
||||
" ;\n" +
|
||||
"\n" +
|
||||
"ID : [a-zA-Z]+ ; // match identifiers\n" +
|
||||
"WS : [ \\t\\r\\n]+ -> skip ; // toss out whitespace\n";
|
||||
|
||||
String found = execParser("T.g4", grammar, "TParser", "TLexer", "s", "a+b", true);
|
||||
assertEquals("(expr a + (expr b))\n", found);
|
||||
|
||||
String expecting =
|
||||
"line 1:1 reportAttemptingFullContext d=1 (expr), input='+'\n" +
|
||||
"line 1:2 reportContextSensitivity d=1 (expr), input='+b'\n";
|
||||
assertEquals(expecting, this.stderrDuringParse);
|
||||
|
||||
found = execParser("T.g4", grammar, "TParser", "TLexer", "s", "a+b*c", true);
|
||||
assertEquals("(expr a + (expr b * (expr c)))\n", found);
|
||||
|
||||
expecting =
|
||||
"line 1:1 reportAttemptingFullContext d=1 (expr), input='+'\n" +
|
||||
"line 1:2 reportContextSensitivity d=1 (expr), input='+b'\n" +
|
||||
"line 1:3 reportAttemptingFullContext d=1 (expr), input='*'\n" +
|
||||
"line 1:5 reportAmbiguity d=1 (expr): ambigAlts={1, 2}, input='*c'\n";
|
||||
assertEquals(expecting, this.stderrDuringParse);
|
||||
}
|
||||
|
||||
}
|
||||
Loading…
Reference in New Issue