feat(list): introduce toDictionary()

README.md

@@ -11,17 +11,6 @@
     <img alt="codeclimate" src="https://api.codeclimate.com/v1/badges/f40c9fff2927e49c3ea2/maintainability">
   </a>
 </p>
-<p align="center">
-  <a href="https://greenkeeper.io">
-    <img alt="greenkeeper" src="https://badges.greenkeeper.io/semantic-release/semantic-release.svg">
-  </a>
-  <a href="https://david-dm.org/patrickmichalina/typescript-monads">
-    <img alt="greenkeeper" src="https://david-dm.org/patrickmichalina/typescript-monads/status.svg">
-  </a>
-  <a href="https://david-dm.org/patrickmichalina/typescript-monads?type=dev">
-    <img alt="greenkeeper" src="https://david-dm.org/patrickmichalina/typescript-monads/dev-status.svg">
-  </a>
-</p>
 <p align="center">
   <a href="https://github.com/semantic-release/semantic-release">
     <img alt="semantic-release" src="https://img.shields.io/badge/%20%20%F0%9F%93%A6%F0%9F%9A%80-semantic--release-e10079.svg">

package.json

@@ -23,7 +23,12 @@
     "maybe",
     "result",
     "either",
-    "functional"
+    "list",
+    "functional",
+    "list-monad",
+    "maybe-monad",
+    "either-monad",
+    "result-monad"
   ],
   "scripts": {
     "test": "jest",

src/list/list.spec.ts

@@ -2,8 +2,9 @@ import { List } from './list'
 import { listFrom } from './list.factory'
 
 class Animal {
-  constructor(public name: string) { }
+  constructor(public name: string, public nickname?: string) { }
 }
+
 class Dog extends Animal {
   dogtag!: string
   dogyear!: number
@@ -228,6 +229,24 @@ describe(List.name, () => {
     })
   })
 
+  describe('ToDictionary', () => {
+    const Rex = new Dog('Rex', 'Rdawg')
+    const Meow = new Cat('Meow')
+    const sut = List.of<Animal>(Rex, Meow)
+
+    it('should handle nominal keyed case', () => {
+      expect(sut.toDictionary('name')).toEqual({ Rex, Meow })
+    })
+
+    it('should handle unkeyed', () => {
+      expect(sut.toDictionary()).toEqual({ 0: Rex, 1: Meow })
+    })
+
+    it('should handle missing keys', () => {
+      expect(sut.toDictionary('nickname')).toEqual({ Rdawg: Rex })
+    })
+  })
+
   // describe('OrderBy', () => {
   //   it('should order by object', () => {
   //     const dog1 = new Dog('Atlas')

src/list/list.ts

@@ -210,6 +210,26 @@ export class List<T> {
     return this.filter(a => a instanceof type)
   }
 
+
+  /**
+   * Converts the list into an object with numbered indices mathing the array position of the item.
+   */
+  public toDictionary(): { [key: number]: T }
+
+  /**
+   * Converts the list into an object deriving key from the specified property.
+   */
+  public toDictionary(key: keyof T): { [key: string]: T }
+  public toDictionary(key?: keyof T): { [key: number]: T } | { [key: string]: T } {
+    return this.reduce((acc, curr, idx) => {
+      return key
+        ? curr[key]
+          ? { ...acc, [curr[key] as any]: curr }
+          : acc
+        : { ...acc, [idx]: curr }
+    }, {})
+  }
+
   // /**
   //  * Sorts the elements of a sequence in ascending order.
   //  */