ork.cql.3.16.0.source-code.fhirpath.g4 Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of cql Show documentation
The cql library for the Clinical Quality Language Java reference implementation
There is a newer version: 3.18.0
grammar fhirpath;

// Grammar rules
// [FHIRPath](http://hl7.org/fhirpath/N1) Normative Release

//prog: line (line)*;
//line: ID ( '(' expr ')') ':' expr '\r'? '\n';

expression
        : term                                                      #termExpression
        | expression '.' invocation                                 #invocationExpression
        | expression '[' expression ']'                             #indexerExpression
        | ('+' | '-') expression                                    #polarityExpression
        | expression ('*' | '/' | 'div' | 'mod') expression         #multiplicativeExpression
        | expression ('+' | '-' | '&') expression                   #additiveExpression
        | expression ('is' | 'as') typeSpecifier                    #typeExpression
        | expression '|' expression                                 #unionExpression
        | expression ('<=' | '<' | '>' | '>=') expression           #inequalityExpression
        | expression ('=' | '~' | '!=' | '!~') expression           #equalityExpression
        | expression ('in' | 'contains') expression                 #membershipExpression
        | expression 'and' expression                               #andExpression
        | expression ('or' | 'xor') expression                      #orExpression
        | expression 'implies' expression                           #impliesExpression
        //| (IDENTIFIER)? '=>' expression                             #lambdaExpression
        ;

term
        : invocation                                            #invocationTerm
        | literal                                               #literalTerm
        | externalConstant                                      #externalConstantTerm
        | '(' expression ')'                                    #parenthesizedTerm
        ;

literal
        : '{' '}'                                               #nullLiteral
        | ('true' | 'false')                                    #booleanLiteral
        | STRING                                                #stringLiteral
        | NUMBER                                                #numberLiteral
        | DATE                                                  #dateLiteral
        | DATETIME                                              #dateTimeLiteral
        | TIME                                                  #timeLiteral
        | quantity                                              #quantityLiteral
        ;

externalConstant
        : '%' ( identifier | STRING )
        ;

invocation                          // Terms that can be used after the function/member invocation '.'
        : identifier                                            #memberInvocation
        | function                                              #functionInvocation
        | '$this'                                               #thisInvocation
        | '$index'                                              #indexInvocation
        | '$total'                                              #totalInvocation
        ;

function
        : identifier '(' paramList? ')'
        ;

paramList
        : expression (',' expression)*
        ;

quantity
        : NUMBER unit?
        ;

unit
        : dateTimePrecision
        | pluralDateTimePrecision
        | STRING // UCUM syntax for units of measure
        ;

dateTimePrecision
        : 'year' | 'month' | 'week' | 'day' | 'hour' | 'minute' | 'second' | 'millisecond'
        ;

pluralDateTimePrecision
        : 'years' | 'months' | 'weeks' | 'days' | 'hours' | 'minutes' | 'seconds' | 'milliseconds'
        ;

typeSpecifier
        : qualifiedIdentifier
        ;

qualifiedIdentifier
        : identifier ('.' identifier)*
        ;

identifier
        : IDENTIFIER
        | DELIMITEDIDENTIFIER
        | 'as'
        | 'contains'
        | 'in'
        | 'is'
        ;


/****************************************************************
    Lexical rules
*****************************************************************/

/*
NOTE: The goal of these rules in the grammar is to provide a date
token to the parser. As such it is not attempting to validate that
the date is a correct date, that task is for the parser or interpreter.
*/

DATE
        : '@' DATEFORMAT
        ;

DATETIME
        : '@' DATEFORMAT 'T' (TIMEFORMAT TIMEZONEOFFSETFORMAT?)?
        ;

TIME
        : '@' 'T' TIMEFORMAT
        ;

fragment DATEFORMAT
        : [0-9][0-9][0-9][0-9] ('-'[0-9][0-9] ('-'[0-9][0-9])?)?
        ;

fragment TIMEFORMAT
        : [0-9][0-9] (':'[0-9][0-9] (':'[0-9][0-9] ('.'[0-9]+)?)?)?
        ;

fragment TIMEZONEOFFSETFORMAT
        : ('Z' | ('+' | '-') [0-9][0-9]':'[0-9][0-9])
        ;

IDENTIFIER
        : ([A-Za-z] | '_')([A-Za-z0-9] | '_')*            // Added _ to support CQL (FHIR could constrain it out)
        ;

DELIMITEDIDENTIFIER
        : '`' (ESC | .)*? '`'
        ;

STRING
        : '\'' (ESC | .)*? '\''
        ;

// Also allows leading zeroes now (just like CQL and XSD)
NUMBER
        : [0-9]+('.' [0-9]+)?
        ;

// Pipe whitespace to the HIDDEN channel to support retrieving source text through the parser.
WS
        : [ \r\n\t]+ -> channel(HIDDEN)
        ;

COMMENT
        : '/*' .*? '*/' -> channel(HIDDEN)
        ;

LINE_COMMENT
        : '//' ~[\r\n]* -> channel(HIDDEN)
        ;

fragment ESC
        : '\\' ([`'\\/fnrt] | UNICODE)    // allow \`, \', \\, \/, \f, etc. and \uXXX
        ;

fragment UNICODE
        : 'u' HEX HEX HEX HEX
        ;

fragment HEX
        : [0-9a-fA-F]
        ;