pegjs/lib/compiler/passes/report-duplicate-rules.js
David Majda ff7193776e Avoid aligning "="
The only exception left are instances where aligning "=" helps to
express symmetry between lines.

See #443.
2016-09-22 09:56:29 +02:00

29 lines
678 B
JavaScript

"use strict";
let GrammarError = require("../../grammar-error");
let visitor = require("../visitor");
// Checks that each rule is defined only once.
function reportDuplicateRules(ast) {
let rules = {};
let check = visitor.build({
rule: function(node) {
if (rules.hasOwnProperty(node.name)) {
throw new GrammarError(
"Rule \"" + node.name + "\" is already defined "
+ "at line " + rules[node.name].start.line + ", "
+ "column " + rules[node.name].start.column + ".",
node.location
);
}
rules[node.name] = node.location;
}
});
check(ast);
}
module.exports = reportDuplicateRules;