Add array/pop (#64)

* Add pop method for arrays

* Add return type for pop method

* Add some meanigful questions

* Correct question

Co-authored-by: Krystian Boruciński <krystian.borucinski@sandstream.pl>

Author: kborucinski

README.md

@@ -375,6 +375,35 @@ Partitions the given array to the ones that pass the given predicate function an
 ```
 <!-- prettier-ignore-end -->
 
+#### pop
+
+Returns the given array without the last element.
+
+##### Type signature
+
+<!-- prettier-ignore-start -->
+```typescript
+(xs: any[]) => any[]
+```
+<!-- prettier-ignore-end -->
+
+##### Examples
+
+<!-- prettier-ignore-start -->
+```javascript
+pop([1, 2, 3, 4]); // ⇒ [1, 2, 3]
+```
+
+```javascript
+pop([]); // ⇒ []
+```
+<!-- prettier-ignore-end -->
+
+##### Questions
+
+- How to get an array without the last element?
+- How to remove the last element from an array?
+
 #### range
 
 Generates an array of numbers from 0 to n - 1.

array/README.md

@@ -358,6 +358,35 @@ Partitions the given array to the ones that pass the given predicate function an
 ```
 <!-- prettier-ignore-end -->
 
+# pop
+
+Returns the given array without the last element.
+
+## Type signature
+
+<!-- prettier-ignore-start -->
+```typescript
+(xs: any[]) => any[]
+```
+<!-- prettier-ignore-end -->
+
+## Examples
+
+<!-- prettier-ignore-start -->
+```javascript
+pop([1, 2, 3, 4]); // ⇒ [1, 2, 3]
+```
+
+```javascript
+pop([]); // ⇒ []
+```
+<!-- prettier-ignore-end -->
+
+## Questions
+
+- How to get an array without the last element?
+- How to remove the last element from an array?
+
 # range
 
 Generates an array of numbers from 0 to n - 1.

array/index.js

@@ -23,6 +23,7 @@ import minMax from "./minMax.js";
 import multiple from "./multiple.js";
 import none from "./none.js";
 import partition from "./partition.js";
+import pop from "./pop.js";
 import range from "./range.js";
 import removeAt from "./removeAt.js";
 import repeat from "./repeat.js";
@@ -71,6 +72,7 @@ export {
   multiple,
   none,
   partition,
+  pop,
   range,
   removeAt,
   repeat,
@@ -120,6 +122,7 @@ export default {
   multiple,
   none,
   partition,
+  pop,
   range,
   removeAt,
   repeat,

array/index.ts

@@ -23,6 +23,7 @@ import minMax from "./minMax";
 import multiple from "./multiple";
 import none from "./none";
 import partition from "./partition";
+import pop from "./pop";
 import range from "./range";
 import removeAt from "./removeAt";
 import repeat from "./repeat";
@@ -71,6 +72,7 @@ export {
   multiple,
   none,
   partition,
+  pop,
   range,
   removeAt,
   repeat,
@@ -120,6 +122,7 @@ export default {
   multiple,
   none,
   partition,
+  pop,
   range,
   removeAt,
   repeat,

array/pop.js

@@ -0,0 +1,3 @@
+import take from "./take.js";
+
+export default xs => take(xs.length - 1)(xs);

array/pop.json

@@ -0,0 +1,19 @@
+{
+  "name": "pop",
+  "description": "Returns the given array without the last element.",
+  "signature": "(xs: any[]) => any[]",
+  "examples": [
+    {
+      "language": "javascript",
+      "content": "pop([1, 2, 3, 4]); // ⇒ [1, 2, 3]"
+    },
+    {
+      "language": "javascript",
+      "content": "pop([]); // ⇒ []"
+    }
+  ],
+  "questions": [
+    "How to get an array without the last element?",
+    "How to remove the last element from an array?"
+  ]
+}

array/pop.md

@@ -0,0 +1,28 @@
+# pop
+
+Returns the given array without the last element.
+
+## Type signature
+
+<!-- prettier-ignore-start -->
+```typescript
+(xs: any[]) => any[]
+```
+<!-- prettier-ignore-end -->
+
+## Examples
+
+<!-- prettier-ignore-start -->
+```javascript
+pop([1, 2, 3, 4]); // ⇒ [1, 2, 3]
+```
+
+```javascript
+pop([]); // ⇒ []
+```
+<!-- prettier-ignore-end -->
+
+## Questions
+
+- How to get an array without the last element?
+- How to remove the last element from an array?

array/pop.test.ts

@@ -0,0 +1,13 @@
+/* eslint-env jest */
+// @ts-ignore ambiguous import
+import pop from "./pop";
+
+describe("pop", () => {
+  it("returns the given array without the last element", () => {
+    expect(pop([1, 2, 3, 4])).toEqual([1, 2, 3]);
+  });
+
+  it("returns an empty array when the given array was empty", () => {
+    expect(pop([])).toEqual([]);
+  });
+});

array/pop.ts

@@ -0,0 +1,3 @@
+import take from "./take";
+
+export default (xs: any[]): any[] => take(xs.length - 1)(xs);