chevrotain/lib/src/utils/utils.js

Chevrotain is a high performance fault tolerant javascript parsing DSL for building recursive decent parsers

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
/*
 Utils using lodash style API. (not necessarily 100% compliant) for functional and other utils.
 These utils should replace usage of lodash in the production code base. not because they are any better...
 but for the purpose of being a dependency free library.

 The hotspots in the code are already written in imperative style for performance reasons.
 so writing several dozen utils which may be slower than the original lodash, does not matter as much
 considering they will not be invoked in hotspots...
 */
function isEmpty(arr) {
    return arr && arr.length === 0;
}
exports.isEmpty = isEmpty;
function keys(obj) {
    if (obj === undefined || obj === null) {
        return [];
    }
    return Object.keys(obj);
}
exports.keys = keys;
function values(obj) {
    var vals = [];
    var keys = Object.keys(obj);
    for (var i = 0; i < keys.length; i++) {
        vals.push(obj[keys[i]]);
    }
    return vals;
}
exports.values = values;
function mapValues(obj, callback) {
    var result = [];
    var objKeys = keys(obj);
    for (var idx = 0; idx < objKeys.length; idx++) {
        var currKey = objKeys[idx];
        result.push(callback.call(null, obj[currKey], currKey));
    }
    return result;
}
exports.mapValues = mapValues;
function map(arr, callback) {
    var result = [];
    for (var idx = 0; idx < arr.length; idx++) {
        result.push(callback.call(null, arr[idx], idx));
    }
    return result;
}
exports.map = map;
function flatten(arr) {
    var result = [];
    for (var idx = 0; idx < arr.length; idx++) {
        var currItem = arr[idx];
        if (Array.isArray(currItem)) {
            result = result.concat(flatten(currItem));
        }
        else {
            result.push(currItem);
        }
    }
    return result;
}
exports.flatten = flatten;
function first(arr) {
    return isEmpty(arr) ? undefined : arr[0];
}
exports.first = first;
function last(arr) {
    var len = arr && arr.length;
    return len ? arr[len - 1] : undefined;
}
exports.last = last;
function forEach(collection, iteratorCallback) {
    if (Array.isArray(collection)) {
        for (var i = 0; i < collection.length; i++) {
            iteratorCallback.call(null, collection[i], i);
        }
    }
    else if (isObject(collection)) {
        var colKeys = keys(collection);
        for (var i = 0; i < colKeys.length; i++) {
            var key = colKeys[i];
            var value = collection[key];
            iteratorCallback.call(null, value, key);
        }
    }
    else {
        /* istanbul ignore next */
        throw Error("non exhaustive match");
    }
}
exports.forEach = forEach;
function isString(item) {
    return typeof item === "string";
}
exports.isString = isString;
function isUndefined(item) {
    return item === undefined;
}
exports.isUndefined = isUndefined;
function isFunction(item) {
    return item instanceof Function;
}
exports.isFunction = isFunction;
function drop(arr, howMuch) {
    if (howMuch === void 0) { howMuch = 1; }
    return arr.slice(howMuch, arr.length);
}
exports.drop = drop;
function dropRight(arr, howMuch) {
    if (howMuch === void 0) { howMuch = 1; }
    return arr.slice(0, arr.length - howMuch);
}
exports.dropRight = dropRight;
function filter(arr, predicate) {
    var result = [];
    if (Array.isArray(arr)) {
        for (var i = 0; i < arr.length; i++) {
            var item = arr[i];
            if (predicate.call(null, item)) {
                result.push(item);
            }
        }
    }
    return result;
}
exports.filter = filter;
function reject(arr, predicate) {
    return filter(arr, function (item) { return !predicate(item); });
}
exports.reject = reject;
function pick(obj, predicate) {
    var keys = Object.keys(obj);
    var result = {};
    for (var i = 0; i < keys.length; i++) {
        var currKey = keys[i];
        var currItem = obj[currKey];
        if (predicate(currItem)) {
            result[currKey] = currItem;
        }
    }
    return result;
}
exports.pick = pick;
function has(obj, prop) {
    if (isObject(obj)) {
        return obj.hasOwnProperty(prop);
    }
    return false;
}
exports.has = has;
function contains(arr, item) {
    return find(arr, function (currItem) { return currItem === item; }) !== undefined ? true : false;
}
exports.contains = contains;
/**
 * shallow clone
 */
function cloneArr(arr) {
    var newArr = [];
    for (var i = 0; i < arr.length; i++) {
        newArr.push(arr[i]);
    }
    return newArr;
}
exports.cloneArr = cloneArr;
/**
 * shallow clone
 */
function cloneObj(obj) {
    var clonedObj = {};
    for (var key in obj) {
        /* istanbul ignore else */
        if (Object.prototype.hasOwnProperty.call(obj, key)) {
            clonedObj[key] = obj[key];
        }
    }
    return clonedObj;
}
exports.cloneObj = cloneObj;
function find(arr, predicate) {
    for (var i = 0; i < arr.length; i++) {
        var item = arr[i];
        if (predicate.call(null, item)) {
            return item;
        }
    }
    return undefined;
}
exports.find = find;
function findAll(arr, predicate) {
    var found = [];
    for (var i = 0; i < arr.length; i++) {
        var item = arr[i];
        if (predicate.call(null, item)) {
            found.push(item);
        }
    }
    return found;
}
exports.findAll = findAll;
function reduce(arrOrObj, iterator, initial) {
    var vals = Array.isArray(arrOrObj)
        ? arrOrObj
        : values(arrOrObj);
    var accumulator = initial;
    for (var i = 0; i < vals.length; i++) {
        accumulator = iterator.call(null, accumulator, vals[i], i);
    }
    return accumulator;
}
exports.reduce = reduce;
function compact(arr) {
    return reject(arr, function (item) { return item === null || item === undefined; });
}
exports.compact = compact;
function uniq(arr, identity) {
    if (identity === void 0) { identity = function (item) { return item; }; }
    var identities = [];
    return reduce(arr, function (result, currItem) {
        var currIdentity = identity(currItem);
        if (contains(identities, currIdentity)) {
            return result;
        }
        else {
            identities.push(currIdentity);
            return result.concat(currItem);
        }
    }, []);
}
exports.uniq = uniq;
function partial(func) {
    var restArgs = [];
    for (var _i = 1; _i < arguments.length; _i++) {
        restArgs[_i - 1] = arguments[_i];
    }
    var firstArg = [null];
    var allArgs = firstArg.concat(restArgs);
    return Function.bind.apply(func, allArgs);
}
exports.partial = partial;
function isArray(obj) {
    return Array.isArray(obj);
}
exports.isArray = isArray;
function isRegExp(obj) {
    return obj instanceof RegExp;
}
exports.isRegExp = isRegExp;
function isObject(obj) {
    return obj instanceof Object;
}
exports.isObject = isObject;
function every(arr, predicate) {
    for (var i = 0; i < arr.length; i++) {
        if (!predicate(arr[i], i)) {
            return false;
        }
    }
    return true;
}
exports.every = every;
function difference(arr, values) {
    return reject(arr, function (item) { return contains(values, item); });
}
exports.difference = difference;
function some(arr, predicate) {
    for (var i = 0; i < arr.length; i++) {
        if (predicate(arr[i])) {
            return true;
        }
    }
    return false;
}
exports.some = some;
function indexOf(arr, value) {
    for (var i = 0; i < arr.length; i++) {
        if (arr[i] === value) {
            return i;
        }
    }
    return -1;
}
exports.indexOf = indexOf;
function sortBy(arr, orderFunc) {
    var result = cloneArr(arr);
    result.sort(function (a, b) { return orderFunc(a) - orderFunc(b); });
    return result;
}
exports.sortBy = sortBy;
function zipObject(keys, values) {
    if (keys.length !== values.length) {
        throw Error("can't zipObject with different number of keys and values!");
    }
    var result = {};
    for (var i = 0; i < keys.length; i++) {
        result[keys[i]] = values[i];
    }
    return result;
}
exports.zipObject = zipObject;
/**
 * mutates! (and returns) target
 */
function assign(target) {
    var sources = [];
    for (var _i = 1; _i < arguments.length; _i++) {
        sources[_i - 1] = arguments[_i];
    }
    for (var i = 0; i < sources.length; i++) {
        var curSource = sources[i];
        var currSourceKeys = keys(curSource);
        for (var j = 0; j < currSourceKeys.length; j++) {
            var currKey = currSourceKeys[j];
            target[currKey] = curSource[currKey];
        }
    }
    return target;
}
exports.assign = assign;
/**
 * mutates! (and returns) target
 */
function assignNoOverwrite(target) {
    var sources = [];
    for (var _i = 1; _i < arguments.length; _i++) {
        sources[_i - 1] = arguments[_i];
    }
    for (var i = 0; i < sources.length; i++) {
        var curSource = sources[i];
        if (isUndefined(curSource)) {
            continue;
        }
        var currSourceKeys = keys(curSource);
        for (var j = 0; j < currSourceKeys.length; j++) {
            var currKey = currSourceKeys[j];
            if (!has(target, currKey)) {
                target[currKey] = curSource[currKey];
            }
        }
    }
    return target;
}
exports.assignNoOverwrite = assignNoOverwrite;
function defaults() {
    var sources = [];
    for (var _i = 0; _i < arguments.length; _i++) {
        sources[_i] = arguments[_i];
    }
    return assignNoOverwrite.apply(null, [{}].concat(sources));
}
exports.defaults = defaults;
function groupBy(arr, groupKeyFunc) {
    var result = {};
    forEach(arr, function (item) {
        var currGroupKey = groupKeyFunc(item);
        var currGroupArr = result[currGroupKey];
        if (currGroupArr) {
            currGroupArr.push(item);
        }
        else {
            result[currGroupKey] = [item];
        }
    });
    return result;
}
exports.groupBy = groupBy;
/**
 * Merge obj2 into obj1.
 * Will overwrite existing properties with the same name
 */
function merge(obj1, obj2) {
    var result = cloneObj(obj1);
    var keys2 = keys(obj2);
    for (var i = 0; i < keys2.length; i++) {
        var key = keys2[i];
        var value = obj2[key];
        result[key] = value;
    }
    return result;
}
exports.merge = merge;
function NOOP() { }
exports.NOOP = NOOP;
function IDENTITY(item) {
    return item;
}
exports.IDENTITY = IDENTITY;
//# sourceMappingURL=utils.js.map