@neutrium/quantity/dist/parsers/MooQtyLexer.js

The NeutriumJS unit conversion module.

import moo from 'moo/moo.js';
import { UnitTokenManager } from '../UnitTokenManager.js';
export class MooQtyLexer {
    _lexer;
    constructor() {
        let rules = {
            "ws": " ",
            "pwr": "^",
            "mul": ["*", "."],
            "div": "/",
            "lParen": '(',
            "rParen": ')',
            "signedFloat": /[-+]?[0-9]*\.[0-9]+(?:[eE][-+]?[0-9]+)?/,
            "integer": /[-+]?[0-9]+/
        };
        const tm = UnitTokenManager.instance;
        rules["unit"] = [
            ...Object.keys(tm.getMap('prefix')),
            ...Object.keys(tm.getMap('unit'))
        ].sort((a, b) => b.length - a.length);
        this._lexer = moo.compile(rules);
    }
    get lexer() {
        return this._lexer;
    }
    //
    // Converts a string representing a quantity with units into an array
    // of tokens
    //
    // @param {string} val - The string to tokenize
    //
    // @returns {Token[]} An array of tokens from the string
    //
    // @throws {QtyError} if target units are incompatible???
    //
    // @example
    // const lex = new MooUnitTokenizer();
    // lex.tokenize("meter"); // Output:
    //
    tokenize(val) {
        this.lexer.reset(val);
        return Array.from(this.lexer);
    }
    next() {
        return this.lexer.next();
    }
}