pragmatic-fp-ts/lib/Mutable.js

Opinionated functional programming library with easy use in mind

"use strict";
/*
 * A mutable value that behaves like a quantum particle: it can be formed until
 * the first time it's observed
 */
Object.defineProperty(exports, "__esModule", { value: true });
exports.MutablePrimitive = exports.MutableObject = exports.MutableArray = exports.Mutable = void 0;
const Mutable = (clone) => (initialValue) => {
    let value = clone(initialValue);
    let wasRead = false;
    const preventRaces = () => {
        if (wasRead) {
            throw new Error("Can not alter mutable value after it was consumed");
        }
    };
    return {
        set: (newValue) => {
            preventRaces();
            value = newValue;
        },
        update: (fn) => {
            preventRaces();
            value = fn(value);
        },
        change: (fn) => {
            preventRaces();
            fn(value);
        },
        value: () => {
            wasRead = true;
            return value;
        },
        toString: () => `Mutable ${JSON.stringify(value)}`,
    };
};
exports.Mutable = Mutable;
const cloneArray = (coll) => coll.concat();
const MutableArray = (coll) => (0, exports.Mutable)(cloneArray)(coll);
exports.MutableArray = MutableArray;
const cloneObject = (obj) => (Object.assign({}, obj));
const MutableObject = (obj) => (0, exports.Mutable)(cloneObject)(obj);
exports.MutableObject = MutableObject;
const clonePrimitive = (value) => value;
const MutablePrimitive = (value) => (0, exports.Mutable)(clonePrimitive)(value);
exports.MutablePrimitive = MutablePrimitive;