This page specifies the complete grammar of PQL captured in the ANTLR notation. ANTLR (ANother Tool for Language Recognition) is a parser generator for reading and translating structured text or binary files. ANTLR can take a grammar of a language as input and generate source code for a parser that can build and walk syntax trees. The language is specified using a context-free grammar which is expressed using extended Backus-Naur Form.
PQL grammar is proposed below. The latest version of the grammar is available here.
/*
[The "BSD licence"]
Copyright (c) 2014-2016 Artem Polyvyanyy (http://polyvyanyy.com/)
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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*/
// PQL version 1.2 grammar for ANTLR v4
grammar PQL;
query : selectQuery |
insertQuery ;
selectQuery : variables
SELECT attributes
FROM locations
(WHERE predicate)? EOS ;
insertQuery : variables
INSERT trace
INTO locations
(WHERE predicate)? EOS ;
variables : variable* ;
variable : varName ASSIGN
setOfTasks EOS ;
varName : VARIABLE_NAME ;
attributes : attribute (SEP attribute)* ;
attribute : universe
| attributeName ;
locations : location (SEP location)* ;
location : universe
| locationPath ;
universe : UNIVERSE ;
attributeName : STRING ;
locationPath : STRING ;
setOfTasks : tasks
| union
| intersection
| difference ;
tasks : varName
| setOfAllTasks
| setOfTasksLiteral
| setOfTasksConstruction
| setOfTasksParentheses ;
setOfAllTasks :
GET_TASKS LP RP;
setOfTasksLiteral :
LB (task (SEP task)*)? RB ;
trace :
LTB (event (SEP event)*)? RTB ;
event : universe | task;
task : approximate label
| label (LSB similarity RSB)? ;
approximate: TILDE ;
label : STRING ;
similarity : SIMILARITY ;
setOfTasksConstruction :
unaryPredicateConstruction
| binaryPredicateConstruction ;
unaryPredicateConstruction :
(GET_TASKS)unaryPredicateName
LP setOfTasks RP ;
binaryPredicateConstruction :
(GET_TASKS)binaryPredicateName
LP setOfTasks SEP setOfTasks
SEP anyAll RP ;
anyAll : ANY | ALL ;
unaryPredicateName : CAN_OCCUR
| ALWAYS_OCCURS;
unaryTracePredicateName : EXECUTES;
binaryPredicateName : CAN_CONFLICT
| CAN_COOCCUR
| CONFLICT
| COOCCUR
| TOTAL_CAUSAL
| TOTAL_CONCUR ;
predicate : proposition
| conjunction
| disjunction
| logicalTest ;
proposition: unaryPredicate
| binaryPredicate
| unaryTracePredicate
| unaryPredicateMacro
| binaryPredicateMacro
| setPredicate
| truthValue
| parentheses
| negation ;
unaryPredicate : unaryPredicateName
LP task RP ;
binaryPredicate : binaryPredicateName
LP task SEP task RP ;
unaryTracePredicate :
unaryTracePredicateName
LP trace RP ;
unaryPredicateMacro : unaryPredicateName
LP setOfTasks SEP anyAll RP ;
binaryPredicateMacro:
binaryPredicateMacroTaskSet
| binaryPredicateMacroSetSet ;
binaryPredicateMacroTaskSet :
binaryPredicateName LP task
SEP setOfTasks SEP anyAll RP ;
binaryPredicateMacroSetSet :
binaryPredicateName
LP setOfTasks SEP setOfTasks
SEP anySomeEachAll RP ;
anySomeEachAll : ANY | SOME | EACH | ALL ;
setPredicate : taskInSetOfTasks
| setComparison ;
taskInSetOfTasks : task IN setOfTasks ;
setComparison : setOfTasks
setComparisonOperator
setOfTasks ;
setComparisonOperator : identical
| different
| overlapsWith
| subsetOf
| properSubsetOf ;
truthValue : TRUE
| FALSE ;
logicalTest: isTrue
| isNotTrue
| isFalse
| isNotFalse ;
union : (tasks | difference |
intersection) UNION (tasks |
difference | intersection)
(UNION (tasks | difference
| intersection))* ;
intersection : (tasks | difference)
INTERSECTION
(tasks | difference)
(INTERSECTION (tasks
| difference))* ;
difference : tasks DIFFERENCE tasks
| tasks DIFFERENCE
difference ;
negation : NOT proposition ;
isTrue : proposition IS TRUE ;
isNotTrue : proposition IS NOT TRUE ;
isFalse : proposition IS FALSE ;
isNotFalse : proposition IS NOT FALSE ;
disjunction : (proposition | logicalTest |
conjunction) OR (proposition |
logicalTest | conjunction) (OR
(proposition | logicalTest
| conjunction))* ;
conjunction : (proposition | logicalTest)
AND (proposition | logicalTest)
(AND (proposition
| logicalTest))* ;
parentheses : LP proposition RP
| LP conjunction RP
| LP disjunction RP
| LP logicalTest RP ;
setOfTasksParentheses : LP varName RP
| LP universe RP
| LP setOfTasksLiteral RP
| LP setOfTasksConstruction RP
| LP union RP
| LP difference RP
| LP intersection RP
| LP setOfTasksParentheses RP ;
UNIVERSE : '*' ;
STRING : DQ ( ESC_SEQ
| ~('\\'|'"') )* DQ ;
VARIABLE_NAME: ('a'..'z'|'_')
('a'..'z'|'0'..'9'|'_')*;
SIMILARITY : '1' | '0' ('.' '0'..'9'+)?
| '.' '0'..'9'+ ;
LP : '(' ;
RP : ')' ;
LB : '{' ;
RB : '}' ;
LSB : '[' ;
RSB : ']' ;
LTB : '<' ;
RTB : '>' ;
DQ : '"' ;
EOS : ';' ;
SEP : ',' ;
ASSIGN : '=' ;
TILDE : '~' ;
ESC_SEQ : '\\' ('\"'|'\\'|'/'|'b'|
'f'|'n'|'r'|'t')
| UNICODE_ESC ;
UNICODE_ESC : '\\' 'u' HEX_DIGIT
HEX_DIGIT HEX_DIGIT HEX_DIGIT ;
HEX_DIGIT : ('0'..'9'|
'a'..'f'|'A'..'F') ;
WS : [ \r\t\n]+ -> skip ;
LINE_COMMENT: '--' ~[\r\n]* -> skip ;
SELECT : 'SELECT' ;
INSERT : 'INSERT' ;
INTO : 'INTO' ;
FROM : 'FROM' ;
WHERE : 'WHERE' ;
EQUALS : 'EQUALS' ;
OVERLAPS : 'OVERLAPS' ;
WITH : 'WITH' ;
SUBSET : 'SUBSET' ;
PROPER : 'PROPER' ;
GET_TASKS : 'GetTasks' ;
NOT : 'NOT' ;
AND : 'AND' ;
OR : 'OR' ;
ANY : 'ANY' ;
SOME : 'SOME' ;
EACH : 'EACH' ;
ALL : 'ALL' ;
IN : 'IN' ;
IS : 'IS' ;
OF : 'OF' ;
TRUE : 'TRUE' ;
FALSE : 'FALSE' ;
identical : EQUALS ;
different : NOT EQUALS ;
overlapsWith : OVERLAPS WITH ;
subsetOf : IS SUBSET OF ;
properSubsetOf : IS PROPER SUBSET OF ;
UNION : 'UNION' ;
INTERSECTION : 'INTERSECT' ;
DIFFERENCE : 'EXCEPT' ;
CAN_OCCUR : 'CanOccur' ;
ALWAYS_OCCURS : 'AlwaysOccurs' ;
EXECUTES : 'Executes' ;
CAN_CONFLICT : 'CanConflict' ;
CAN_COOCCUR : 'CanCooccur' ;
CONFLICT : 'Conflict' ;
COOCCUR : 'Cooccur' ;
TOTAL_CAUSAL : 'TotalCausal' ;
TOTAL_CONCUR : 'TotalConcurrent' ;