@beenotung/tslib/random.js

utils library in Typescript

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.Random = exports.alphabetNumLetters = exports.symbolLetters = exports.base58Letters = exports.visibleLetters = exports.lowerCaseLetters = exports.upperCaseLetters = exports.digits = exports.genStringRange = void 0;
const enum_1 = require("./enum");
const string_1 = require("./string");
/**
 * @param start {number} inclusive
 * @param end {number} exclusive
 * */
function genStringRange(start, end) {
    let s = '';
    for (let i = start; i < end; i++) {
        s += String.fromCharCode(i);
    }
    return s;
}
exports.genStringRange = genStringRange;
exports.digits = genStringRange(48, 48 + 10);
exports.upperCaseLetters = genStringRange(65, 65 + 26);
exports.lowerCaseLetters = genStringRange(65 + 32, 65 + 32 + 26);
/** visible characters only in ascii range */
exports.visibleLetters = genStringRange(32, 127);
/** base58btc format, removed '0OIl' and '+/' */
exports.base58Letters = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz';
exports.symbolLetters = string_1.str_minus(exports.visibleLetters, exports.digits + exports.upperCaseLetters + exports.lowerCaseLetters);
exports.alphabetNumLetters = exports.upperCaseLetters + exports.lowerCaseLetters + exports.digits;
var Random;
(function (Random) {
    /** @return number : lower <= value < upper */
    function nextInt(upper = Number.MAX_SAFE_INTEGER, lower = 0) {
        return Math.floor(Math.random() * (upper - lower) + lower);
    }
    Random.nextInt = nextInt;
    function nextFloat(upper = Number.MAX_VALUE, lower = 0, decimal = 2) {
        const a = nextInt(upper, lower);
        const b = nextInt(Math.pow(10, decimal));
        if (b === 0) {
            return a;
        }
        const p = Math.pow(10, Math.ceil(Math.log10(b)));
        return a + b / p;
    }
    Random.nextFloat = nextFloat;
    function nextBool(prob = 0.5) {
        return Math.random() < prob;
    }
    Random.nextBool = nextBool;
    function probablyRun(prop, run) {
        if (nextBool(prop)) {
            return run();
        }
    }
    Random.probablyRun = probablyRun;
    /** @return real number : -1 .. 1 */
    function nextNP1() {
        return Math.random() * 2 - 1;
    }
    Random.nextNP1 = nextNP1;
    /**
     * Nullable
     * */
    function element(xs) {
        return xs[nextInt(xs.length, 0)];
    }
    Random.element = element;
    function nextDate(after = new Date('2016-12-12'), before = new Date('2018-12-12')) {
        const diff = before.getTime() - after.getTime();
        const time = Random.nextInt(after.getTime() + diff, after.getTime());
        return new Date(time);
    }
    Random.nextDate = nextDate;
    /**
     * @return value of enum (not key of enum)
     * */
    function nextEnum(e) {
        const key = Random.element(enum_1.enum_keys(e));
        return e[key];
    }
    Random.nextEnum = nextEnum;
    function nextEnumKey(e) {
        return Random.element(enum_1.enum_keys(e));
    }
    Random.nextEnumKey = nextEnumKey;
    function nextBuffer(n) {
        // tslint:disable:no-bitwise
        const res = new Buffer(n);
        for (let i = 0; i < n; i++) {
            res[i] = (Math.random() * 256) >>> 0;
        }
        return res;
        // tslint:enable:no-bitwise
    }
    Random.nextBuffer = nextBuffer;
    function nextString(n, pool = exports.visibleLetters) {
        let s = '';
        for (; s.length < n;) {
            s += element(pool);
        }
        return s;
    }
    Random.nextString = nextString;
})(Random = exports.Random || (exports.Random = {}));
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