35 lines
888 B
JavaScript
35 lines
888 B
JavaScript
import grammar from '/imports/parser/grammar';
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import nearley from 'nearley';
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const nearleyGrammar = nearley.Grammar.fromCompiled(grammar);
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export default function parser() {
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return new nearley.Parser(nearleyGrammar);
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}
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export function parse(string) {
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let parser = new nearley.Parser(nearleyGrammar);
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parser.feed(string);
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let results = parser.results;
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if (results.length === 1) {
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return results[0];
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} else if (results.length === 0) {
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// Valid parsing up until now, but need more
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throw new EndOfInputError('Unexpected end of input');
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} else {
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console.warn('Grammar is ambiguous!', { string, results });
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return results[0];
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}
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}
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export function prettifyParseError(e) {
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if (e.message) e = e.message
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return e.toString().split('.')[0];
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}
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class EndOfInputError extends Error {
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constructor(message = '', ...args) {
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super(message, ...args);
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}
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}
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