lexer grammar HooLexer;

IDENTIFIER: Letter LetterOrDigit*;

fragment DIGIT: [0-9];

DECIMAL_LITERAL: '0' | ('+' | '-')? [1-9] [0-9]*;

FLOAT_LITERAL: ('+' | '-')? Digits+ '.' Digits+ (
		[eE] [+-]? Digits+
	)?;

BOOL_LITERAL: 'true' | 'false';

CHAR_LITERAL: '\'' (~['\\\r\n] | EscapeSequence) '\'';

STRING_LITERAL: '"' (~["\\\r\n] | EscapeSequence)* '"';

TEXT_BLOCK: '"""' [ \t]* [\r\n] (. | EscapeSequence)*? '"""';

NULL_LITERAL: 'null';

WS: [ \t\r\n\u000C]+ -> channel(HIDDEN);
COMMENT: '/*' .*? '*/' -> channel(HIDDEN);
LINE_COMMENT: '//' ~[\r\n]* -> channel(HIDDEN);

fragment EscapeSequence:
	'\\' 'u005c'? [btnfr"'\\]
	| '\\' 'u005c'? ([0-3]? [0-7])? [0-7]
	| '\\' 'u'+ HexDigit HexDigit HexDigit HexDigit;

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

fragment Digits: [0-9];

fragment LetterOrDigit: Letter | [0-9];

fragment Letter:
	[a-zA-Z$_]
	| ~[\u0000-\u007F\uD800-\uDBFF]
	| [\uD800-\uDBFF] [\uDC00-\uDFFF];