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    A lexical analyzer generator used by jison. It takes a lexical grammar definition (either in JSON or Bison's lexical grammar format) and outputs a JavaScript lexer.


    npm install @gerhobbelt/jison-lex

    or the entire bundle via

    npm install jison-gho

    Then the jison-lex library is located in the subdirectory packages/jison-lex/ of the jison-gho monorepo, i.e. .../node_modules/jison-gho/packages/jison-lex/.

    Alternatively, the entire jison-lex API is also available via the jison API itself as can be seen from this internal jison code snippet:

    import Lexer from '../packages/jison-lex';
    import ebnfParser from '../packages/ebnf-parser';
    import lexParser from '../packages/lex-parser';
    import grammarPrinter from './util/grammar-printer.js';
    import helpers from '../packages/helpers-lib';
    var rmCommonWS = helpers.rmCommonWS;
    var camelCase  = helpers.camelCase;
    var code_exec  = helpers.exec;
    import XRegExp from '@gerhobbelt/xregexp';
    import recast from '@gerhobbelt/recast';
    import astUtils from '@gerhobbelt/ast-util';
    import json5 from '@gerhobbelt/json5';
    // Also export other APIs: the JISON module should act as a 'facade' for the others,
    // so applications using the JISON compiler itself can rely on it providing everything
    // in a guaranteed compatible version as it allows userland code to use the precise
    // same APIs as JISON will be using itself:
    Jison.Lexer = Lexer;
    Jison.ebnfParser = ebnfParser;
    Jison.lexParser = lexParser;
    Jison.codeExec = code_exec;
    Jison.XRegExp = XRegExp;
    Jison.recast = recast;
    Jison.astUtils = astUtils;
    Jison.JSON5 = json5;
    Jison.prettyPrint = grammarPrinter;
    Jison.rmCommonWS = rmCommonWS;
    Jison.mkStdOptions = mkStdOptions;
    Jison.camelCase = camelCase;
    Jison.autodetectAndConvertToJSONformat = autodetectAndConvertToJSONformat;
    Jison.Parser = Parser;
    export default Jison;

    hence you can get at it this way, for example:

    import jisonAPI from 'jison-gho';
    // get a reference to the full `jison-lex` API:
    const jisonLexAPI = jisonAPI.Lexer;


    Follow the install & build directions of the monorepo.

    You can also only build this particular subpackage by cd-ing into this directory and then invoking the local make:

    cd packages/jison-lex

    This will generate the rollup/babel-postprocessed ES6 and ES5 compatible libraries and CLI in the local dist/ directory.

    Note about ES6/rollup usage vs. ES5

    All dist/ library files are 'self-contained': they include all 'local imports' from within this jison monorepo in order to deliver a choice of source files for your perusal where you only need to worry about importing external dependencies (such as recast).

    As such, these dist/ files should be easier to minify and/or use in older (ES5) environments.


    Iff you use rollup or similar tools in an ES6/ES2015/ES2017 setting, then the package.json::module has already been set up for you to use the original sources instead!


    Usage: jison-lex [file] [options]
    file     file containing a lexical grammar
       -o FILE, --outfile FILE       Filename and base module name of the generated parser
       -t TYPE, --module-type TYPE   The type of module to generate (commonjs, js)
       --version                     print version and exit

    programmatic usage

    var JisonLex = require('@gerhobbelt/jison-lex');
    var grammar = {
      rules: [
        ["x", "return 'X';" ],
        ["y", "return 'Y';" ],
        ["$", "return 'EOF';" ]
    // or load from a file
    // var grammar = fs.readFileSync('mylexer.l', 'utf8');
    // generate source
    var lexerSource = JisonLex.generate(grammar);
    // or create a parser in memory
    var lexer = new JisonLex(grammar);
    // => 'X'
    // => 'Y'



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    npm i @gerhobbelt/jison-lex


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