var utils = require("../../utils"), GrammarError = require("../../grammar-error"); /* Checks that all referenced rules exist. */ module.exports = function(ast) { function nop() {} function checkExpression(node) { check(node.expression); } function checkSubnodes(propertyName) { return function(node) { utils.each(node[propertyName], check); }; } var check = utils.buildNodeVisitor({ grammar: checkSubnodes("rules"), rule: checkExpression, named: checkExpression, choice: checkSubnodes("alternatives"), action: checkExpression, sequence: checkSubnodes("elements"), labeled: checkExpression, text: checkExpression, simple_and: checkExpression, simple_not: checkExpression, semantic_and: nop, semantic_not: nop, optional: checkExpression, zero_or_more: checkExpression, one_or_more: checkExpression, rule_ref: function(node) { if (!utils.findRuleByName(ast, node.name)) { throw new GrammarError( "Referenced rule \"" + node.name + "\" does not exist." ); } }, literal: nop, "class": nop, any: nop }); check(ast); };