ractive/src/parse/Parser/expressions/conditional.js

Next-generation DOM manipulation

import types from 'config/types';
import getLogicalOr from 'parse/Parser/expressions/logicalOr';
import errors from 'parse/Parser/expressions/shared/errors';

// The conditional operator is the lowest precedence operator, so we start here
export default function ( parser ) {
	var start, expression, ifTrue, ifFalse;

	expression = getLogicalOr( parser );
	if ( !expression ) {
		return null;
	}

	start = parser.pos;

	parser.allowWhitespace();

	if ( !parser.matchString( '?' ) ) {
		parser.pos = start;
		return expression;
	}

	parser.allowWhitespace();

	ifTrue = parser.readExpression();
	if ( !ifTrue ) {
		parser.error( errors.expectedExpression );
	}

	parser.allowWhitespace();

	if ( !parser.matchString( ':' ) ) {
		parser.error( 'Expected ":"' );
	}

	parser.allowWhitespace();

	ifFalse = parser.readExpression();
	if ( !ifFalse ) {
		parser.error( errors.expectedExpression );
	}

	return {
		t: types.CONDITIONAL,
		o: [ expression, ifTrue, ifFalse ]
	};
}