RE group production emits a non-captured group #14
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For deep lexer rules like [ShEx's PN_CHARS_BASE](https://github.com/shexjs/shex.js/blob/b5cb30708d7c69550a07f1329aaf97cdb8eed737/packages/shex-parser/lib/ShExJison.jison#L255), the [emitted rule](https://github.com/shexjs/shex.js/blob/b5cb30708d7c69550a07f1329aaf97cdb8eed737/packages/shex-parser/lib/ShExJison.js#L934) has an enormous number of capture groups. When parsing a large input like [FHIR.shex](https://hl7.org/fhir/R4B/fhir.schema.shex.zip) gives a stack error: ``` /home/eric/checkouts/shexSpec/shex.js/packages/shex-parser/shex-parser.js:251 throw errors[0]; ^ RangeError: Maximum call stack size exceeded at String.match (<anonymous>) at JisonLexer.next (/home/eric/checkouts/shexSpec/shex.js/node_modules/@ts-jison/lexer/lib/lexer.js:225:37) at JisonLexer.lex (/home/eric/checkouts/shexSpec/shex.js/node_modules/@ts-jison/lexer/lib/lexer.js:269:22) at JisonLexer.lex (/home/eric/checkouts/shexSpec/shex.js/node_modules/@ts-jison/lexer/lib/lexer.js:274:25) at lex (/home/eric/checkouts/shexSpec/shex.js/node_modules/@ts-jison/parser/lib/parser.js:51:28) at JisonParser.parse (/home/eric/checkouts/shexSpec/shex.js/node_modules/@ts-jison/parser/lib/parser.js:68:30) at ShExJisonParser.runParser [as parse] (/home/eric/checkouts/shexSpec/shex.js/packages/shex-parser/shex-parser.js:231:22) at Object.<anonymous> (/home/eric/checkouts/shexSpec/shex.js/parseFhir.js:10:38) at Module._compile (node:internal/modules/cjs/loader:1119:14) at Module._extensions..js (node:internal/modules/cjs/loader:1173:10) { parsed: null } ``` Eliminating capture groups fixes the problem and makes parsing wayyyy faster. (I generated this grammar using ts-jison, but the same happens with jison.)
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For deep lexer rules like ShEx's PN_CHARS_BASE, the emitted rule has an enormous number of capture groups. When parsing a large input like FHIR.shex gives a stack error:
Eliminating capture groups fixes the problem and makes parsing wayyyy faster.
(I generated this grammar using ts-jison, but the same happens with jison.)