grammar LolSharp;


options 
{
	language=CSharp;
	output=AST;
	ASTLabelType=CommonTree;
}

tokens 
{
	PROGRAM;
	USING;
	PRINT;
	LITERAL_STRING;
	LITERAL_INT;
	LITERAL_FLOAT;
	LITERAL_FALSE;
	LITERAL_TRUE;
	USINGDECLS;
	VARIABLE_DECLARATION;
	VARIABLE_REFERENCE;
	ASSIGN;
}

program	:	'HAI' '\n' (using_decl '\n'+)* block+ 'KTHXBYE' '\n'* -> ^(PROGRAM ^(USINGDECLS using_decl*) block+)
	;

block	:	(statement '\n'+)+ -> statement+
	;
	
statement
	:	print_statement
	|	var_decl
	|	assignment
	|	
	;

using_decl
	:	'I CAN HAS' ID '?' -> ^(USING ID)
	;
	
var_decl:	'I HAS A' ID /*('ITZ' expression)?*/ -> ^(VARIABLE_DECLARATION ID /*expression?*/)
	;
	
assignment
	:	lh_expression 'R' expression -> ^(ASSIGN lh_expression expression)
	;
	
expression
	:	literal_expression
	|	ID -> ^(VARIABLE_REFERENCE ID)
	;

lh_expression
	:	ID -> ^(VARIABLE_REFERENCE ID)
	;
	
literal_expression
	:	literal_string
	|	literal_int
	|	literal_float
	|	literal_boolean
	;
	
literal_string
	:	RAW_QUOTED_STRING -> ^(LITERAL_STRING RAW_QUOTED_STRING)
	;

literal_int
	: 	s='-'? DIGITS -> ^(LITERAL_INT $s? DIGITS)
	;
	
literal_float
	:	s='-'? lit=LITERAL_FLOAT_SEQ -> ^(LITERAL_FLOAT $s? $lit)
	;
	
literal_boolean
	:	'FAIL' -> ^(LITERAL_FALSE)
	|	'WIN' -> ^(LITERAL_TRUE)
	;
	
COMMENT	:	'BTW' COMMENT_CHAR* '\n' { $channel=HIDDEN; }
	;

COMMENT_CHAR 
	:	~('\n') { $channel=HIDDEN; }
	;
	
print_statement
	:	'VISIBLE' expression -> ^(PRINT expression)
	;
		
ID	:	LETTER (LETTER | DIGIT)*
	;
	
LETTER
	:	'a'..'z' | 'A'..'Z'
	;

DIGIT	:	'0'..'9'
	;
	
DIGITS	:	DIGIT+
	;
	
LITERAL_FLOAT_SEQ
 	:	DIGITS '.' DIGITS
 	;

WS 	:	(' ' | '\t' | '\n' | '\r') { $channel=HIDDEN; } 
	;
	
RAW_QUOTED_STRING
	:	'"' ( ('\\' ESCAPE_CODE) | ~( '\\' | '\n' | '"'))* '"'
	;

ESCAPE_CODE
	:	'n'
	|	't'
	|	'\\'
	|	'"'
	|	DIGIT DIGIT DIGIT DIGIT	
	;