Prepare repository for merge

javascript/snippets/juxt.md

@@ -0,0 +1,28 @@
+---
+title: Juxtapose functions
+type: snippet
+tags: [function]
+cover: colorful-plastic
+dateModified: 2020-10-20T23:29:39+03:00
+---
+
+Takes several functions as argument and returns a function that is the juxtaposition of those functions.
+
+- Use `Array.prototype.map()` to return a `fn` that can take a variable number of `args`.
+- When `fn` is called, return an array containing the result of applying each `fn` to the `args`.
+
+```js
+const juxt = (...fns) => (...args) => [...fns].map(fn => [...args].map(fn));
+```
+
+```js
+juxt(
+  x => x + 1,
+  x => x - 1,
+  x => x * 10
+)(1, 2, 3); // [[2, 3, 4], [0, 1, 2], [10, 20, 30]]
+juxt(
+  s => s.length,
+  s => s.split(' ').join('-')
+)('30 seconds of code'); // [[18], ['30-seconds-of-code']]
+```