grammar XFilter;

options 
{
    language=CSharp3;
    TokenLabelType=CommonToken;
    output=AST;
    ASTLabelType=CommonTree;
}

tokens
{
	OPERATOR;
	COMPAREEXPRESSION;
	FUNCTIONEXPRESSION;
	XIFUNC;
}



@lexer::namespace{xi.OpMisc.Filter}
@parser::namespace{xi.OpMisc.Filter}



/*
 * Parser Rules
 */

public
filterfunc	:	logical_expression EOF!
					  ;



logical_expression
						:	booleanAndExpression (OPERATOR_OR^ booleanAndExpression )* 
						;

booleanAndExpression
						: compareexpression (OPERATOR_AND^ compareexpression)*
						;



function		: FUNCTIONIDENTIIFER LBrace comparand (Comma comparand)* RBrace	-> ^(FUNCTIONEXPRESSION FUNCTIONIDENTIIFER comparand comparand*)
						;

expression	: (comparand) operator_comp^ comparand
						;


operator_comp	
						:	OPERATOR_COMP_EQ
						|	OPERATOR_COMP_GT
						|	OPERATOR_COMP_GE
						|	OPERATOR_COMP_LT
						|	OPERATOR_COMP_LE 
						|	OPERATOR_COMP_NE 
						;

logical_op	:	OPERATOR_AND
						|	OPERATOR_OR
						;

compareexpression	
						: (NOT^ )? LBrace! logical_expression RBrace!
						| (NOT^ )? function
						| (NOT^ )? expression
						;






constant
	: STRING_LITERAL
	| CHARACTER_LITERAL
	| FloatString
	| Number
	| DIGIT
	| Boolean
	| DateTime
	;


comparand	: (xIIDENTIFIER_COLUMN|constant);

xIIDENTIFIER_COLUMN
				: ICOL0	
				| XIFUNC
				| ICOL1							
				;


//			



/*
 * Lexer Rules
 */

XIFUNC_PROLOG
		:	'XI.TIS' (LETTER1)+
		;

fragment
LETTER1
	:	'A'..'Z'
	|	'a'..'z'
	| DIGIT
	|	'_'
	;

VAL_QUANTIFIER
	: 'P'
	| 'p'
	| 'Z'
	| 'z'
	;

OPERATOR_COMP_EQ	: '==' ;
OPERATOR_COMP_GT	: '>' ;
OPERATOR_COMP_GE	: '>=' ;
OPERATOR_COMP_LT	: '<' ;
OPERATOR_COMP_LE	: '<=' ;
OPERATOR_COMP_NE	: '!=' ;

OPERATOR_AND
	: '&&' | 'and' | 'AND'
	;

OPERATOR_OR
	: '||' | 'or' | 'OR'
	;




protected NOT	:	'!' | 'not';



fragment 
DIGIT		:	('0'..'9');

protected FloatString
	:	'-'? (DIGIT)* '.' (DIGIT)+
	;

protected Number:	'-'? (DIGIT)+ (VAL_QUANTIFIER)?
	;		
	
protected Boolean
	:		'true' | 'false' | 'True' | 'False'
	;

protected TimePart
	: 'T'DIGIT DIGIT? ':' DIGIT DIGIT? ':' DIGIT DIGIT?
	;
protected DateTime
	:	DIGIT DIGIT DIGIT DIGIT '-' DIGIT DIGIT? '-' DIGIT DIGIT? (TimePart)*
	;



protected Comma: ',';
protected LBrace: '(';
protected RBrace: ')';



fragment
XIDENTIFIER	:	'#'
						;

fragment
BACKSLASH		:	'\\'
						;

fragment
BLANK				: ' '
						;

FUNCTIONIDENTIIFER	
						:	('A'..'Z')(LETTER1)*
						;

CHARACTER_LITERAL
    :   '\'' ( EscapeSequence | ~('\''|BACKSLASH) )* '\''
    ;

STRING_LITERAL
    :  '"' ( EscapeSequence | ~(BACKSLASH|'"') )* '"'
    ;

fragment
ESC_IDENT
		: BACKSLASH ( '@'	)
		;
		


EscapeSequence
    :   '\\' ('b'|'t'|'n'|'r'|'\"'|'\''|'\\')
    ;


Comment			: '/*' ( options {greedy=false;} : . )* '*/' {$channel=Hidden;}
						;


WS					:   ( ' '
						|			'\t'
						|			'\r'
						|			'\n'
							)  {$channel=Hidden;}
						;






ICOL0	
		:	('@' DIGIT+ '@')
		;


ICOL1	
		:	'@' ( ESC_IDENT | ~('@') )+ '@'
		;


fragment
CONSTANTS
		:	STRING_LITERAL
		| CHARACTER_LITERAL
		| DateTime
		| Number
		| Boolean
		| FloatString
		| XIFUNC
		;


XIFUNC
		: (XIDENTIFIER XIFUNC_PROLOG BLANK* '(' BLANK* (CONSTANTS) (BLANK* ',' BLANK* (CONSTANTS))* BLANK* ')' BLANK? XIDENTIFIER)
		;