@phosphor/algorithm/lib/find.js

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
/*-----------------------------------------------------------------------------
| Copyright (c) 2014-2017, PhosphorJS Contributors
|
| Distributed under the terms of the BSD 3-Clause License.
|
| The full license is in the file LICENSE, distributed with this software.
|----------------------------------------------------------------------------*/
var iter_1 = require("./iter");
/**
 * Find the first value in an iterable which matches a predicate.
 *
 * @param object - The iterable or array-like object to search.
 *
 * @param fn - The predicate function to apply to the values.
 *
 * @returns The first matching value, or `undefined` if no matching
 *   value is found.
 *
 * #### Complexity
 * Linear.
 *
 * #### Example
 * ```typescript
 * import { find } from '@phosphor/algorithm';
 *
 * interface IAnimal { species: string, name: string };
 *
 * function isCat(value: IAnimal): boolean {
 *   return value.species === 'cat';
 * }
 *
 * let data: IAnimal[] = [
 *   { species: 'dog', name: 'spot' },
 *   { species: 'cat', name: 'fluffy' },
 *   { species: 'alligator', name: 'pocho' }
 * ];
 *
 * find(data, isCat).name;  // 'fluffy'
 * ```
 */
function find(object, fn) {
    var index = 0;
    var it = iter_1.iter(object);
    var value;
    while ((value = it.next()) !== undefined) {
        if (fn(value, index++)) {
            return value;
        }
    }
    return undefined;
}
exports.find = find;
/**
 * Find the index of the first value which matches a predicate.
 *
 * @param object - The iterable or array-like object to search.
 *
 * @param fn - The predicate function to apply to the values.
 *
 * @returns The index of the first matching value, or `-1` if no
 *   matching value is found.
 *
 * #### Complexity
 * Linear.
 *
 * #### Example
 * ```typescript
 * import { findIndex } from '@phosphor/algorithm';
 *
 * interface IAnimal { species: string, name: string };
 *
 * function isCat(value: IAnimal): boolean {
 *   return value.species === 'cat';
 * }
 *
 * let data: IAnimal[] = [
 *   { species: 'dog', name: 'spot' },
 *   { species: 'cat', name: 'fluffy' },
 *   { species: 'alligator', name: 'pocho' }
 * ];
 *
 * findIndex(data, isCat);  // 1
 * ```
 */
function findIndex(object, fn) {
    var index = 0;
    var it = iter_1.iter(object);
    var value;
    while ((value = it.next()) !== undefined) {
        if (fn(value, index++)) {
            return index - 1;
        }
    }
    return -1;
}
exports.findIndex = findIndex;
/**
 * Find the minimum value in an iterable.
 *
 * @param object - The iterable or array-like object to search.
 *
 * @param fn - The 3-way comparison function to apply to the values.
 *   It should return `< 0` if the first value is less than the second.
 *   `0` if the values are equivalent, or `> 0` if the first value is
 *   greater than the second.
 *
 * @returns The minimum value in the iterable. If multiple values are
 *   equivalent to the minimum, the left-most value is returned. If
 *   the iterable is empty, this returns `undefined`.
 *
 * #### Complexity
 * Linear.
 *
 * #### Example
 * ```typescript
 * import { min } from '@phosphor/algorithm';
 *
 * function numberCmp(a: number, b: number): number {
 *   return a - b;
 * }
 *
 * min([7, 4, 0, 3, 9, 4], numberCmp);  // 0
 * ```
 */
function min(object, fn) {
    var it = iter_1.iter(object);
    var value = it.next();
    if (value === undefined) {
        return undefined;
    }
    var result = value;
    while ((value = it.next()) !== undefined) {
        if (fn(value, result) < 0) {
            result = value;
        }
    }
    return result;
}
exports.min = min;
/**
 * Find the maximum value in an iterable.
 *
 * @param object - The iterable or array-like object to search.
 *
 * @param fn - The 3-way comparison function to apply to the values.
 *   It should return `< 0` if the first value is less than the second.
 *   `0` if the values are equivalent, or `> 0` if the first value is
 *   greater than the second.
 *
 * @returns The maximum value in the iterable. If multiple values are
 *   equivalent to the maximum, the left-most value is returned. If
 *   the iterable is empty, this returns `undefined`.
 *
 * #### Complexity
 * Linear.
 *
 * #### Example
 * ```typescript
 * import { max } from '@phosphor/algorithm';
 *
 * function numberCmp(a: number, b: number): number {
 *   return a - b;
 * }
 *
 * max([7, 4, 0, 3, 9, 4], numberCmp);  // 9
 * ```
 */
function max(object, fn) {
    var it = iter_1.iter(object);
    var value = it.next();
    if (value === undefined) {
        return undefined;
    }
    var result = value;
    while ((value = it.next()) !== undefined) {
        if (fn(value, result) > 0) {
            result = value;
        }
    }
    return result;
}
exports.max = max;
/**
 * Find the minimum and maximum values in an iterable.
 *
 * @param object - The iterable or array-like object to search.
 *
 * @param fn - The 3-way comparison function to apply to the values.
 *   It should return `< 0` if the first value is less than the second.
 *   `0` if the values are equivalent, or `> 0` if the first value is
 *   greater than the second.
 *
 * @returns A 2-tuple of the `[min, max]` values in the iterable. If
 *   multiple values are equivalent, the left-most values are returned.
 *   If the iterable is empty, this returns `undefined`.
 *
 * #### Complexity
 * Linear.
 *
 * #### Example
 * ```typescript
 * import { minmax } from '@phosphor/algorithm';
 *
 * function numberCmp(a: number, b: number): number {
 *   return a - b;
 * }
 *
 * minmax([7, 4, 0, 3, 9, 4], numberCmp);  // [0, 9]
 * ```
 */
function minmax(object, fn) {
    var it = iter_1.iter(object);
    var value = it.next();
    if (value === undefined) {
        return undefined;
    }
    var vmin = value;
    var vmax = value;
    while ((value = it.next()) !== undefined) {
        if (fn(value, vmin) < 0) {
            vmin = value;
        }
        else if (fn(value, vmax) > 0) {
            vmax = value;
        }
    }
    return [vmin, vmax];
}
exports.minmax = minmax;