buckets-js/src/_base.js

Buckets is a complete, fully tested and documented data structure library written in pure JavaScript.

'use strict';

/**
 * Top level namespace for Buckets,
 * a JavaScript data structure library.
 * @name buckets
 */
var buckets = {};

/**
 * Default function to compare element order.
 * @function
 * @private
 */
buckets.defaultCompare = function (a, b) {
    if (a < b) {
        return -1;
    }
    if (a === b) {
        return 0;
    }
    return 1;
};

/**
 * Default function to test equality.
 * @function
 * @private
 */
buckets.defaultEquals = function (a, b) {
    return a === b;
};

/**
 * Default function to convert an object to a string.
 * @function
 * @private
 */
buckets.defaultToString = function (item) {
    if (item === null) {
        return 'BUCKETS_NULL';
    }
    if (buckets.isUndefined(item)) {
        return 'BUCKETS_UNDEFINED';
    }
    if (buckets.isString(item)) {
        return item;
    }
    return item.toString();
};

/**
 * Checks if the given argument is a function.
 * @function
 * @private
 */
buckets.isFunction = function (func) {
    return (typeof func) === 'function';
};

/**
 * Checks if the given argument is undefined.
 * @function
 * @private
 */
buckets.isUndefined = function (obj) {
    return obj === undefined;
};

/**
 * Checks if the given argument is a string.
 * @function
 * @private
 */
buckets.isString = function (obj) {
    return Object.prototype.toString.call(obj) === '[object String]';
};

/**
 * Reverses a compare function.
 * @function
 * @private
 */
buckets.reverseCompareFunction = function (compareFunction) {
    if (!buckets.isFunction(compareFunction)) {
        return function (a, b) {
            if (a < b) {
                return 1;
            }
            if (a === b) {
                return 0;
            }
            return -1;
        };
    }
    return function (d, v) {
        return compareFunction(d, v) * -1;
    };

};

/**
 * Returns an equal function given a compare function.
 * @function
 * @private
 */
buckets.compareToEquals = function (compareFunction) {
    return function (a, b) {
        return compareFunction(a, b) === 0;
    };
};