@fauton/cfg/dist/utils/generateNewVariable.js

A package to work with context free grammars and LL1 parsers

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.generateNewVariable = void 0;
/**
 * Generates a random integer between two intervals
 * @param min Left limit of generated int
 * @param max Right limit of generated int
 * @returns A random integer
 */
function randomIntFromInterval(min, max) {
    return Math.floor(Math.random() * (max - min + 1) + min);
}
const CAPITAL_LETTERS = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
const DIGITS = '0123456789';
/**
 * Generates a new variable that is not part of the passed variables array
 * @param variables A set of variables which shouldn't be generated
 * @returns Generated variable string
 */
function generateNewVariable(variables) {
    const variablesSet = new Set(variables);
    // Create a variable with first character to be any capital letter and 2nd letter to be digit
    let newVariable = CAPITAL_LETTERS[randomIntFromInterval(0, CAPITAL_LETTERS.length - 1)] +
        DIGITS[randomIntFromInterval(0, DIGITS.length - 1)];
    // While the new variable is present in our variables set we need to keep on creating it
    while (variablesSet.has(newVariable)) {
        // New variable will be a combination of capital letter and a digit
        newVariable =
            CAPITAL_LETTERS[randomIntFromInterval(0, CAPITAL_LETTERS.length - 1)] +
                DIGITS[randomIntFromInterval(0, DIGITS.length - 1)];
    }
    // Push the newly generated variable to the passed variables array
    variables.push(newVariable);
    return newVariable;
}
exports.generateNewVariable = generateNewVariable;