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Implement semantic predicates

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redux
David Majda 14 years ago
parent 4895f4f8e4
commit af1968054b
5 changed files with 238 additions and 94 deletions
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106
lib/compiler.js
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@ -282,16 +282,18 @@ PEG.Compiler = {
}
},
rule: checkExpression,
choice: checkSubnodes("alternatives"),
sequence: checkSubnodes("elements"),
labeled: checkExpression,
and_predicate: checkExpression,
not_predicate: checkExpression,
optional: checkExpression,
zero_or_more: checkExpression,
one_or_more: checkExpression,
action: checkExpression,
rule: checkExpression,
choice: checkSubnodes("alternatives"),
sequence: checkSubnodes("elements"),
labeled: checkExpression,
simple_and: checkExpression,
simple_not: checkExpression,
semantic_and: nop,
semantic_not: nop,
optional: checkExpression,
zero_or_more: checkExpression,
one_or_more: checkExpression,
action: checkExpression,
rule_ref:
function(node) {
@ -302,9 +304,9 @@ PEG.Compiler = {
}
},
literal: nop,
any: nop,
"class": nop
literal: nop,
any: nop,
"class": nop
};
function check(node) { checkFunctions[node.type](node); }
@ -347,13 +349,15 @@ PEG.Compiler = {
}
},
labeled: checkExpression,
and_predicate: checkExpression,
not_predicate: checkExpression,
optional: checkExpression,
zero_or_more: checkExpression,
one_or_more: checkExpression,
action: checkExpression,
labeled: checkExpression,
simple_and: checkExpression,
simple_not: checkExpression,
semantic_and: nop,
semantic_not: nop,
optional: checkExpression,
zero_or_more: checkExpression,
one_or_more: checkExpression,
action: checkExpression,
rule_ref:
function(node, appliedRules) {
@ -365,9 +369,9 @@ PEG.Compiler = {
check(ast.rules[node.name], appliedRules);
},
literal: nop,
any: nop,
"class": nop
literal: nop,
any: nop,
"class": nop
};
function check(node, appliedRules) {
@ -416,16 +420,18 @@ PEG.Compiler = {
}
},
rule: replaceInExpression,
choice: replaceInSubnodes("alternatives"),
sequence: replaceInSubnodes("elements"),
labeled: replaceInExpression,
and_predicate: replaceInExpression,
not_predicate: replaceInExpression,
optional: replaceInExpression,
zero_or_more: replaceInExpression,
one_or_more: replaceInExpression,
action: replaceInExpression,
rule: replaceInExpression,
choice: replaceInSubnodes("alternatives"),
sequence: replaceInSubnodes("elements"),
labeled: replaceInExpression,
simple_and: replaceInExpression,
simple_not: replaceInExpression,
semantic_and: nop,
semantic_not: nop,
optional: replaceInExpression,
zero_or_more: replaceInExpression,
one_or_more: replaceInExpression,
action: replaceInExpression,
rule_ref:
function(node, from, to) {
@ -434,9 +440,9 @@ PEG.Compiler = {
}
},
literal: nop,
any: nop,
"class": nop
literal: nop,
any: nop,
"class": nop
};
function replace(node, from, to) {
@ -819,7 +825,7 @@ PEG.Compiler = {
return PEG.Compiler.compileNode(node.expression, resultVar);
},
and_predicate: function(node, resultVar) {
simple_and: function(node, resultVar) {
var savedPosVar = PEG.Compiler.generateUniqueIdentifier("savedPos");
var savedReportMatchFailuresVar = PEG.Compiler.generateUniqueIdentifier("savedReportMatchFailuresVar");
var expressionResultVar = PEG.Compiler.generateUniqueIdentifier("result");
@ -846,7 +852,7 @@ PEG.Compiler = {
);
},
not_predicate: function(node, resultVar) {
simple_not: function(node, resultVar) {
var savedPosVar = PEG.Compiler.generateUniqueIdentifier("savedPos");
var savedReportMatchFailuresVar = PEG.Compiler.generateUniqueIdentifier("savedReportMatchFailuresVar");
var expressionResultVar = PEG.Compiler.generateUniqueIdentifier("result");
@ -873,6 +879,30 @@ PEG.Compiler = {
);
},
semantic_and: function(node, resultVar) {
var savedPosVar = PEG.Compiler.generateUniqueIdentifier("savedPos");
return PEG.Compiler.formatCode(
"var ${resultVar} = (function() {${actionCode}})() ? '' : null;",
{
actionCode: node.code,
resultVar: resultVar
}
);
},
semantic_not: function(node, resultVar) {
var savedPosVar = PEG.Compiler.generateUniqueIdentifier("savedPos");
return PEG.Compiler.formatCode(
"var ${resultVar} = (function() {${actionCode}})() ? null : '';",
{
actionCode: node.code,
resultVar: resultVar
}
);
},
optional: function(node, resultVar) {
var expressionResultVar = PEG.Compiler.generateUniqueIdentifier("result");

124
lib/metagrammar.js
Unescape Escape View File

@ -469,61 +469,113 @@ PEG.grammarParser = (function(){
}
var savedPos1 = pos;
var result8 = parse_and(context);
if (result8 !== null) {
var result9 = parse_suffixed(context);
if (result9 !== null) {
var result7 = [result8, result9];
var savedPos3 = pos;
var result16 = parse_and(context);
if (result16 !== null) {
var result17 = parse_action(context);
if (result17 !== null) {
var result15 = [result16, result17];
} else {
var result7 = null;
pos = savedPos1;
var result15 = null;
pos = savedPos3;
}
} else {
var result7 = null;
pos = savedPos1;
var result15 = null;
pos = savedPos3;
}
var result6 = result7 !== null
? (function(expression) {
var result14 = result15 !== null
? (function(code) {
return {
type: "and_predicate",
expression: expression
type: "semantic_and",
code: code
};
})(result7[1])
})(result15[1])
: null;
if (result6 !== null) {
var result0 = result6;
if (result14 !== null) {
var result0 = result14;
} else {
var savedPos0 = pos;
var result4 = parse_not(context);
if (result4 !== null) {
var result5 = parse_suffixed(context);
if (result5 !== null) {
var result3 = [result4, result5];
var savedPos2 = pos;
var result12 = parse_and(context);
if (result12 !== null) {
var result13 = parse_suffixed(context);
if (result13 !== null) {
var result11 = [result12, result13];
} else {
var result3 = null;
pos = savedPos0;
var result11 = null;
pos = savedPos2;
}
} else {
var result3 = null;
pos = savedPos0;
var result11 = null;
pos = savedPos2;
}
var result2 = result3 !== null
var result10 = result11 !== null
? (function(expression) {
return {
type: "not_predicate",
type: "simple_and",
expression: expression
};
})(result3[1])
})(result11[1])
: null;
if (result2 !== null) {
var result0 = result2;
if (result10 !== null) {
var result0 = result10;
} else {
var result1 = parse_suffixed(context);
if (result1 !== null) {
var result0 = result1;
var savedPos1 = pos;
var result8 = parse_not(context);
if (result8 !== null) {
var result9 = parse_action(context);
if (result9 !== null) {
var result7 = [result8, result9];
} else {
var result7 = null;
pos = savedPos1;
}
} else {
var result7 = null;
pos = savedPos1;
}
var result6 = result7 !== null
? (function(code) {
return {
type: "semantic_not",
code: code
};
})(result7[1])
: null;
if (result6 !== null) {
var result0 = result6;
} else {
var result0 = null;;
var savedPos0 = pos;
var result4 = parse_not(context);
if (result4 !== null) {
var result5 = parse_suffixed(context);
if (result5 !== null) {
var result3 = [result4, result5];
} else {
var result3 = null;
pos = savedPos0;
}
} else {
var result3 = null;
pos = savedPos0;
}
var result2 = result3 !== null
? (function(expression) {
return {
type: "simple_not",
expression: expression
};
})(result3[1])
: null;
if (result2 !== null) {
var result0 = result2;
} else {
var result1 = parse_suffixed(context);
if (result1 !== null) {
var result0 = result1;
} else {
var result0 = null;;
};
};
};
};
}

18
lib/metagrammar.pegjs
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@ -82,15 +82,27 @@ labeled
/ prefixed
prefixed
= and expression:suffixed {
= and code:action {
return {
type: "and_predicate",
type: "semantic_and",
code: code
};
}
/ and expression:suffixed {
return {
type: "simple_and",
expression: expression
};
}
/ not code:action {
return {
type: "semantic_not",
code: code
};
}
/ not expression:suffixed {
return {
type: "not_predicate",
type: "simple_not",
expression: expression
};
}

56
test/compiler-test.js
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@ -303,7 +303,7 @@ test("labels", function() {
doesNotParse(parser, "b");
});
test("and predicate", function() {
test("simple and", function() {
var parser = PEG.buildParser('start = "a" &"b" "b"');
parses(parser, "ab", ["a", "", "b"]);
doesNotParse(parser, "ac");
@ -314,7 +314,7 @@ test("and predicate", function() {
*/
});
test("not predicate", function() {
test("simple not", function() {
var parser = PEG.buildParser('start = "a" !"b"');
parses(parser, "a", ["a", ""]);
doesNotParse(parser, "ab");
@ -327,6 +327,22 @@ test("not predicate", function() {
parses(posTestParser, "ac", ["a", "", "c"]);
});
test("semantic and", function() {
var acceptingParser = PEG.buildParser('start = "a" &{ return true; } "b"');
parses(acceptingParser, "ab", ["a", "", "b"]);
var rejectingParser = PEG.buildParser('start = "a" &{ return false; } "b"');
doesNotParse(rejectingParser, "ab");
});
test("semantic not", function() {
var acceptingParser = PEG.buildParser('start = "a" !{ return false; } "b"');
parses(acceptingParser, "ab", ["a", "", "b"]);
var rejectingParser = PEG.buildParser('start = "a" !{ return true; } "b"');
doesNotParse(rejectingParser, "ab");
});
test("optional expressions", function() {
var parser = PEG.buildParser('start = "a"?');
parses(parser, "", "");
@ -386,15 +402,35 @@ test("actions", function() {
});
test("initializer", function() {
var variableDefinitionParser = PEG.buildParser(
var variableInActionParser = PEG.buildParser(
'{ a = 42; }; start = "a" { return a; }'
);
parses(variableDefinitionParser, "a", 42);
parses(variableInActionParser, "a", 42);
var functionDefinitionparser = PEG.buildParser(
var functionInActionParser = PEG.buildParser(
'{ function f() { return 42; } }; start = "a" { return f(); }'
);
parses(variableDefinitionParser, "a", 42);
parses(functionInActionParser, "a", 42);
var variableInSemanticAndParser = PEG.buildParser(
'{ a = 42; }; start = "a" &{ return a === 42; }'
);
parses(variableInSemanticAndParser, "a", ["a", ""]);
var functionInSemanticAndParser = PEG.buildParser(
'{ function f() { return 42; } }; start = "a" &{ return f() === 42; }'
);
parses(functionInSemanticAndParser, "a", ["a", ""]);
var variableInSemanticNotParser = PEG.buildParser(
'{ a = 42; }; start = "a" !{ return a !== 42; }'
);
parses(variableInSemanticNotParser, "a", ["a", ""]);
var functionInSemanticNotParser = PEG.buildParser(
'{ function f() { return 42; } }; start = "a" !{ return f() !== 42; }'
);
parses(functionInSemanticNotParser, "a", ["a", ""]);
});
test("rule references", function() {
@ -568,16 +604,16 @@ test("error messages", function() {
'Expected "c" but "d" found.'
);
var notPredicateParser = PEG.buildParser('start = !"a" "b"');
var simpleNotParser = PEG.buildParser('start = !"a" "b"');
doesNotParseWithMessage(
notPredicateParser,
simpleNotParser,
"c",
'Expected "b" but "c" found.'
);
var andPredicateParser = PEG.buildParser('start = &"a" [a-b]');
var simpleAndParser = PEG.buildParser('start = &"a" [a-b]');
doesNotParseWithMessage(
andPredicateParser,
simpleAndParser,
"c",
'Expected end of input but "c" found.'
);

28
test/metagrammar-test.js
Unescape Escape View File

@ -67,8 +67,20 @@ function nodeWithExpressionConstructor(type) {
}
}
var andPredicate = nodeWithExpressionConstructor("and_predicate");
var notPredicate = nodeWithExpressionConstructor("not_predicate");
function nodeWithCodeConstructor(type) {
return function(code) {
return {
type: type,
code: code
};
}
}
var simpleAnd = nodeWithExpressionConstructor("simple_and");
var simpleNot = nodeWithExpressionConstructor("simple_not");
var semanticAnd = nodeWithCodeConstructor("semantic_and");
var semanticNot = nodeWithCodeConstructor("semantic_not");
var optional = nodeWithExpressionConstructor("optional");
var zeroOrMore = nodeWithExpressionConstructor("zero_or_more");
@ -270,19 +282,21 @@ test("parses sequence", function() {
test("parses labeled", function() {
grammarParserParses(
'start = label:!"abcd"',
oneRuleGrammar(labeled("label", notPredicate(literalAbcd)))
oneRuleGrammar(labeled("label", simpleNot(literalAbcd)))
);
grammarParserParses(
'start = !"abcd"',
oneRuleGrammar(notPredicate(literalAbcd))
oneRuleGrammar(simpleNot(literalAbcd))
);
});
/* Canonical prefixed is "!\"abcd\"". */
test("parses prefixed", function() {
grammarParserParses('start = &"abcd"?', oneRuleGrammar(andPredicate(optionalLiteral)));
grammarParserParses('start = !"abcd"?', oneRuleGrammar(notPredicate(optionalLiteral)));
grammarParserParses('start = "abcd"?', oneRuleGrammar(optionalLiteral));
grammarParserParses('start = &{ code }', oneRuleGrammar(semanticAnd(" code ")));
grammarParserParses('start = &"abcd"?', oneRuleGrammar(simpleAnd(optionalLiteral)));
grammarParserParses('start = !{ code }', oneRuleGrammar(semanticNot(" code ")));
grammarParserParses('start = !"abcd"?', oneRuleGrammar(simpleNot(optionalLiteral)));
grammarParserParses('start = "abcd"?', oneRuleGrammar(optionalLiteral));
});
/* Canonical suffixed is "\"abcd\"?". */

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