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