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30secondsofcode
2019-03-18 06:32:40 +00:00
parent 611c0132fe
commit 9fbb61c79c
12 changed files with 67 additions and 73 deletions
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50
README.md
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@ -671,14 +671,13 @@ const pipeAsyncFunctions = (...fns) => arg => fns.reduce((p, f) => p.then(f), Pr
<summary>Examples</summary>
```js
const sum = pipeAsyncFunctions(
x => x + 1,
x => new Promise(resolve => setTimeout(() => resolve(x + 2), 1000)),
x => x + 3,
async x => (await x) + 4
);
(async() => {
(async () => {
console.log(await sum(5)); // 15 (after one second)
})();
```
@ -2320,13 +2319,12 @@ Use `Array.prototype.filter()` to find array elements that return truthy values
The `func` is invoked with three arguments (`value, index, array`).
```js
const remove = (arr, func) =>
Array.isArray(arr)
? arr.filter(func).reduce((acc, val) => {
arr.splice(arr.indexOf(val), 1);
return acc.concat(val);
}, [])
arr.splice(arr.indexOf(val), 1);
return acc.concat(val);
}, [])
: [];
```
@ -4656,9 +4654,9 @@ chainAsync([
### checkProp
Given a `predicate` function and a `prop` string this curried function will then take an `object` to inspect by calling the property and passing it to the predicate.
Given a `predicate` function and a `prop` string, this curried function will then take an `object` to inspect by calling the property and passing it to the predicate.
It summons `prop` on `obj` and passes it to a provided `predicate` function and returns a masked boolean
Summon `prop` on `obj`, pass it to a provided `predicate` function and return a masked boolean.
```js
const checkProp = (predicate, prop) => obj => !!predicate(obj[prop]);
@ -4669,23 +4667,23 @@ const checkProp = (predicate, prop) => obj => !!predicate(obj[prop]);
```js
const lengthIs4 = checkProp(l => l === 4, 'length')
lengthIs4([]) // false
lengthIs4([1,2,3,4]) // true
lengthIs4(new Set([1,2,3,4])) // false (Set uses Size, not length)
const lengthIs4 = checkProp(l => l === 4, 'length');
lengthIs4([]); // false
lengthIs4([1,2,3,4]); // true
lengthIs4(new Set([1,2,3,4])); // false (Set uses Size, not length)
const session = { user: {} }
const validUserSession = checkProps(u => u.active && !u.disabled, 'user')
const session = { user: {} };
const validUserSession = checkProps(u => u.active && !u.disabled, 'user');
validUserSession(session) // false
validUserSession(session); // false
session.user.active = true
validUserSession(session) // true
session.user.active = true;
validUserSession(session); // true
const noLength(l => l === undefined, 'length')
noLength([]) // false
noLength({}) // true
noLength(new Set()) // true
const noLength(l => l === undefined, 'length');
noLength([]); // false
noLength({}); // true
noLength(new Set()); // true
```
</details>
@ -5545,8 +5543,8 @@ Throws an exception if `n` is a negative number.
const factorial = n =>
n < 0
? (() => {
throw new TypeError('Negative numbers are not allowed!');
})()
throw new TypeError('Negative numbers are not allowed!');
})()
: n <= 1
? 1
: n * factorial(n - 1);
@ -6928,9 +6926,9 @@ const dig = (obj, target) =>
target in obj
? obj[target]
: Object.values(obj).reduce((acc, val) => {
if (acc !== undefined) return acc;
if (typeof val === 'object') return dig(val, target);
}, undefined);
if (acc !== undefined) return acc;
if (typeof val === 'object') return dig(val, target);
}, undefined);
```
<details>

5
docs/adapter.html
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@ -127,14 +127,13 @@ Object<span class="token punctuation">.</span><span class="token function">assig
<span class="token keyword">const</span> fn <span class="token operator">=</span> <span class="token function">overArgs</span><span class="token punctuation">((</span>x<span class="token punctuation">,</span> y<span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">[</span>x<span class="token punctuation">,</span> y<span class="token punctuation">], [</span>square<span class="token punctuation">,</span> double<span class="token punctuation">]);</span>
<span class="token function">fn</span><span class="token punctuation">(</span><span class="token number">9</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">);</span> <span class="token comment">// [81, 6]</span>
</pre></div><div class="card code-card"><div class="corner intermediate"></div><div class="section card-content"><h4 id="pipeasyncfunctions">pipeAsyncFunctions</h4><p>Performs left-to-right function composition for asynchronous functions.</p><p>Use <code>Array.prototype.reduce()</code> with the spread operator (<code>...</code>) to perform left-to-right function composition using <code>Promise.then()</code>. The functions can return a combination of: simple values, <code>Promise</code>'s, or they can be defined as <code>async</code> ones returning through <code>await</code>. All functions must be unary.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">pipeAsyncFunctions</span> <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token operator">...</span>fns<span class="token punctuation">)</span> <span class="token operator">=></span> arg <span class="token operator">=></span> fns<span class="token punctuation">.</span><span class="token function">reduce</span><span class="token punctuation">((</span>p<span class="token punctuation">,</span> f<span class="token punctuation">)</span> <span class="token operator">=></span> p<span class="token punctuation">.</span><span class="token function">then</span><span class="token punctuation">(</span>f<span class="token punctuation">),</span> Promise<span class="token punctuation">.</span><span class="token function">resolve</span><span class="token punctuation">(</span>arg<span class="token punctuation">));</span>
</pre><label class="collapse">examples</label><pre class="section card-examples language-js">
<span class="token keyword">const</span> sum <span class="token operator">=</span> <span class="token function">pipeAsyncFunctions</span><span class="token punctuation">(</span>
</pre><label class="collapse">examples</label><pre class="section card-examples language-js"><span class="token keyword">const</span> sum <span class="token operator">=</span> <span class="token function">pipeAsyncFunctions</span><span class="token punctuation">(</span>
x <span class="token operator">=></span> x <span class="token operator">+</span> <span class="token number">1</span><span class="token punctuation">,</span>
x <span class="token operator">=></span> <span class="token keyword">new</span> <span class="token class-name">Promise</span><span class="token punctuation">(</span>resolve <span class="token operator">=></span> <span class="token function">setTimeout</span><span class="token punctuation">(()</span> <span class="token operator">=></span> <span class="token function">resolve</span><span class="token punctuation">(</span>x <span class="token operator">+</span> <span class="token number">2</span><span class="token punctuation">),</span> <span class="token number">1000</span><span class="token punctuation">)),</span>
x <span class="token operator">=></span> x <span class="token operator">+</span> <span class="token number">3</span><span class="token punctuation">,</span>
<span class="token keyword">async</span> x <span class="token operator">=></span> <span class="token punctuation">(</span><span class="token keyword">await</span> x<span class="token punctuation">)</span> <span class="token operator">+</span> <span class="token number">4</span>
<span class="token punctuation">);
(</span><span class="token keyword">async</span><span class="token punctuation">()</span> <span class="token operator">=></span> <span class="token punctuation">{</span>
(</span><span class="token keyword">async</span> <span class="token punctuation">()</span> <span class="token operator">=></span> <span class="token punctuation">{</span>
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span><span class="token keyword">await</span> <span class="token function">sum</span><span class="token punctuation">(</span><span class="token number">5</span><span class="token punctuation">));</span> <span class="token comment">// 15 (after one second)</span>
<span class="token punctuation">})();</span>
</pre></div><div class="card code-card"><div class="section card-content"><h4><a href="https://frontendmasters.com/courses/es6-right-parts/" target="_blank" rel="noopener noreferrer">Recommended Resource - ES6: The Right Parts</a></h4><p>Learn new ES6 JavaScript language features like arrow function, destructuring, generators & more to write cleaner and more productive, readable programs.</p></div></div><div class="card code-card"><div class="corner intermediate"></div><div class="section card-content"><h4 id="pipefunctions">pipeFunctions</h4><p>Performs left-to-right function composition.</p><p>Use <code>Array.prototype.reduce()</code> with the spread operator (<code>...</code>) to perform left-to-right function composition. The first (leftmost) function can accept one or more arguments; the remaining functions must be unary.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">pipeFunctions</span> <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token operator">...</span>fns<span class="token punctuation">)</span> <span class="token operator">=></span> fns<span class="token punctuation">.</span><span class="token function">reduce</span><span class="token punctuation">((</span>f<span class="token punctuation">,</span> g<span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">(</span><span class="token operator">...</span>args<span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token function">g</span><span class="token punctuation">(</span><span class="token function">f</span><span class="token punctuation">(</span><span class="token operator">...</span>args<span class="token punctuation">)));</span>

28
docs/function.html
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@ -143,25 +143,25 @@ console<span class="token punctuation">.</span><span class="token function">log<
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span><span class="token string">'2 second'</span><span class="token punctuation">);
}
]);</span>
</pre></div><div class="card code-card"><div class="corner beginner"></div><div class="section card-content"><h4 id="checkprop">checkProp</h4><p>Given a <code>predicate</code> function and a <code>prop</code> string this curried function will then take an <code>object</code> to inspect by calling the property and passing it to the predicate.</p><p>It summons <code>prop</code> on <code>obj</code> and passes it to a provided <code>predicate</code> function and returns a masked boolean</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">checkProp</span> <span class="token operator">=</span> <span class="token punctuation">(</span>predicate<span class="token punctuation">,</span> prop<span class="token punctuation">)</span> <span class="token operator">=></span> obj <span class="token operator">=> !!</span><span class="token function">predicate</span><span class="token punctuation">(</span>obj<span class="token punctuation">[</span>prop<span class="token punctuation">]);</span>
</pre></div><div class="card code-card"><div class="corner beginner"></div><div class="section card-content"><h4 id="checkprop">checkProp</h4><p>Given a <code>predicate</code> function and a <code>prop</code> string, this curried function will then take an <code>object</code> to inspect by calling the property and passing it to the predicate.</p><p>Summon <code>prop</code> on <code>obj</code>, pass it to a provided <code>predicate</code> function and return a masked boolean.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">checkProp</span> <span class="token operator">=</span> <span class="token punctuation">(</span>predicate<span class="token punctuation">,</span> prop<span class="token punctuation">)</span> <span class="token operator">=></span> obj <span class="token operator">=> !!</span><span class="token function">predicate</span><span class="token punctuation">(</span>obj<span class="token punctuation">[</span>prop<span class="token punctuation">]);</span>
</pre><label class="collapse">examples</label><pre class="section card-examples language-js">
<span class="token keyword">const</span> lengthIs4 <span class="token operator">=</span> <span class="token function">checkProp</span><span class="token punctuation">(</span>l <span class="token operator">=></span> l <span class="token operator">===</span> <span class="token number">4</span><span class="token punctuation">,</span> <span class="token string">'length'</span><span class="token punctuation">)</span>
<span class="token function">lengthIs4</span><span class="token punctuation">([])</span> <span class="token comment">// false</span>
<span class="token function">lengthIs4</span><span class="token punctuation">([</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">3</span><span class="token punctuation">,</span><span class="token number">4</span><span class="token punctuation">])</span> <span class="token comment">// true</span>
<span class="token function">lengthIs4</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">Set</span><span class="token punctuation">([</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">3</span><span class="token punctuation">,</span><span class="token number">4</span><span class="token punctuation">]))</span> <span class="token comment">// false (Set uses Size, not length)</span>
<span class="token keyword">const</span> lengthIs4 <span class="token operator">=</span> <span class="token function">checkProp</span><span class="token punctuation">(</span>l <span class="token operator">=></span> l <span class="token operator">===</span> <span class="token number">4</span><span class="token punctuation">,</span> <span class="token string">'length'</span><span class="token punctuation">);</span>
<span class="token function">lengthIs4</span><span class="token punctuation">([]);</span> <span class="token comment">// false</span>
<span class="token function">lengthIs4</span><span class="token punctuation">([</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">3</span><span class="token punctuation">,</span><span class="token number">4</span><span class="token punctuation">]);</span> <span class="token comment">// true</span>
<span class="token function">lengthIs4</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">Set</span><span class="token punctuation">([</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">3</span><span class="token punctuation">,</span><span class="token number">4</span><span class="token punctuation">]));</span> <span class="token comment">// false (Set uses Size, not length)</span>
<span class="token keyword">const</span> session <span class="token operator">=</span> <span class="token punctuation">{</span> user<span class="token punctuation">: {} }</span>
<span class="token keyword">const</span> validUserSession <span class="token operator">=</span> <span class="token function">checkProps</span><span class="token punctuation">(</span>u <span class="token operator">=></span> u<span class="token punctuation">.</span>active <span class="token operator">&amp;&amp; !</span>u<span class="token punctuation">.</span>disabled<span class="token punctuation">,</span> <span class="token string">'user'</span><span class="token punctuation">)</span>
<span class="token keyword">const</span> session <span class="token operator">=</span> <span class="token punctuation">{</span> user<span class="token punctuation">: {} };</span>
<span class="token keyword">const</span> validUserSession <span class="token operator">=</span> <span class="token function">checkProps</span><span class="token punctuation">(</span>u <span class="token operator">=></span> u<span class="token punctuation">.</span>active <span class="token operator">&amp;&amp; !</span>u<span class="token punctuation">.</span>disabled<span class="token punctuation">,</span> <span class="token string">'user'</span><span class="token punctuation">);</span>
<span class="token function">validUserSession</span><span class="token punctuation">(</span>session<span class="token punctuation">)</span> <span class="token comment">// false</span>
<span class="token function">validUserSession</span><span class="token punctuation">(</span>session<span class="token punctuation">);</span> <span class="token comment">// false</span>
session<span class="token punctuation">.</span>user<span class="token punctuation">.</span>active <span class="token operator">=</span> <span class="token boolean">true</span>
<span class="token function">validUserSession</span><span class="token punctuation">(</span>session<span class="token punctuation">)</span> <span class="token comment">// true</span>
session<span class="token punctuation">.</span>user<span class="token punctuation">.</span>active <span class="token operator">=</span> <span class="token boolean">true</span><span class="token punctuation">;</span>
<span class="token function">validUserSession</span><span class="token punctuation">(</span>session<span class="token punctuation">);</span> <span class="token comment">// true</span>
<span class="token keyword">const</span> <span class="token function">noLength</span><span class="token punctuation">(</span>l <span class="token operator">=></span> l <span class="token operator">===</span> undefined<span class="token punctuation">,</span> <span class="token string">'length'</span><span class="token punctuation">)</span>
<span class="token function">noLength</span><span class="token punctuation">([])</span> <span class="token comment">// false</span>
<span class="token function">noLength</span><span class="token punctuation">({})</span> <span class="token comment">// true</span>
<span class="token function">noLength</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">Set</span><span class="token punctuation">())</span> <span class="token comment">// true</span>
<span class="token keyword">const</span> <span class="token function">noLength</span><span class="token punctuation">(</span>l <span class="token operator">=></span> l <span class="token operator">===</span> undefined<span class="token punctuation">,</span> <span class="token string">'length'</span><span class="token punctuation">);</span>
<span class="token function">noLength</span><span class="token punctuation">([]);</span> <span class="token comment">// false</span>
<span class="token function">noLength</span><span class="token punctuation">({});</span> <span class="token comment">// true</span>
<span class="token function">noLength</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">Set</span><span class="token punctuation">());</span> <span class="token comment">// true</span>
</pre></div><div class="card code-card"><div class="corner intermediate"></div><div class="section card-content"><h4 id="compose">compose</h4><p>Performs right-to-left function composition.</p><p>Use <code>Array.prototype.reduce()</code> to perform right-to-left function composition. The last (rightmost) function can accept one or more arguments; the remaining functions must be unary.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">compose</span> <span class="token operator">=</span> <span class="token punctuation">(</span><span class="token operator">...</span>fns<span class="token punctuation">)</span> <span class="token operator">=></span> fns<span class="token punctuation">.</span><span class="token function">reduce</span><span class="token punctuation">((</span>f<span class="token punctuation">,</span> g<span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">(</span><span class="token operator">...</span>args<span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token function">f</span><span class="token punctuation">(</span><span class="token function">g</span><span class="token punctuation">(</span><span class="token operator">...</span>args<span class="token punctuation">)));</span>
</pre><label class="collapse">examples</label><pre class="section card-examples language-js"><span class="token keyword">const</span> <span class="token function-variable function">add5</span> <span class="token operator">=</span> x <span class="token operator">=></span> x <span class="token operator">+</span> <span class="token number">5</span><span class="token punctuation">;</span>
<span class="token keyword">const</span> <span class="token function-variable function">multiply</span> <span class="token operator">=</span> <span class="token punctuation">(</span>x<span class="token punctuation">,</span> y<span class="token punctuation">)</span> <span class="token operator">=></span> x <span class="token operator">*</span> y<span class="token punctuation">;</span>

9
docs/index.html
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@ -407,13 +407,12 @@
</pre></div><div class="card code-card"><div class="corner beginner"></div><div class="section card-content"><h4 id="reject">reject</h4><p>Takes a predicate and array, like <code>Array.prototype.filter()</code>, but only keeps <code>x</code> if <code>pred(x) === false</code>.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">reject</span> <span class="token operator">=</span> <span class="token punctuation">(</span>pred<span class="token punctuation">,</span> array<span class="token punctuation">)</span> <span class="token operator">=></span> array<span class="token punctuation">.</span><span class="token function">filter</span><span class="token punctuation">((</span><span class="token operator">...</span>args<span class="token punctuation">)</span> <span class="token operator">=> !</span><span class="token function">pred</span><span class="token punctuation">(</span><span class="token operator">...</span>args<span class="token punctuation">));</span>
</pre><label class="collapse">examples</label><pre class="section card-examples language-js"><span class="token function">reject</span><span class="token punctuation">(</span>x <span class="token operator">=></span> x <span class="token operator">%</span> <span class="token number">2</span> <span class="token operator">===</span> <span class="token number">0</span><span class="token punctuation">, [</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">,</span> <span class="token number">4</span><span class="token punctuation">,</span> <span class="token number">5</span><span class="token punctuation">]);</span> <span class="token comment">// [1, 3, 5]</span>
<span class="token function">reject</span><span class="token punctuation">(</span>word <span class="token operator">=></span> word<span class="token punctuation">.</span>length <span class="token operator">></span> <span class="token number">4</span><span class="token punctuation">, [</span><span class="token string">'Apple'</span><span class="token punctuation">,</span> <span class="token string">'Pear'</span><span class="token punctuation">,</span> <span class="token string">'Kiwi'</span><span class="token punctuation">,</span> <span class="token string">'Banana'</span><span class="token punctuation">]);</span> <span class="token comment">// ['Pear', 'Kiwi']</span>
</pre></div><div class="card code-card"><div class="corner intermediate"></div><div class="section card-content"><h4 id="remove">remove</h4><p>Removes elements from an array for which the given function returns <code>false</code>.</p><p>Use <code>Array.prototype.filter()</code> to find array elements that return truthy values and <code>Array.prototype.reduce()</code> to remove elements using <code>Array.prototype.splice()</code>. The <code>func</code> is invoked with three arguments (<code>value, index, array</code>).</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js">
<span class="token keyword">const</span> <span class="token function-variable function">remove</span> <span class="token operator">=</span> <span class="token punctuation">(</span>arr<span class="token punctuation">,</span> func<span class="token punctuation">)</span> <span class="token operator">=></span>
</pre></div><div class="card code-card"><div class="corner intermediate"></div><div class="section card-content"><h4 id="remove">remove</h4><p>Removes elements from an array for which the given function returns <code>false</code>.</p><p>Use <code>Array.prototype.filter()</code> to find array elements that return truthy values and <code>Array.prototype.reduce()</code> to remove elements using <code>Array.prototype.splice()</code>. The <code>func</code> is invoked with three arguments (<code>value, index, array</code>).</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">remove</span> <span class="token operator">=</span> <span class="token punctuation">(</span>arr<span class="token punctuation">,</span> func<span class="token punctuation">)</span> <span class="token operator">=></span>
Array<span class="token punctuation">.</span><span class="token function">isArray</span><span class="token punctuation">(</span>arr<span class="token punctuation">)</span>
<span class="token operator">?</span> arr<span class="token punctuation">.</span><span class="token function">filter</span><span class="token punctuation">(</span>func<span class="token punctuation">).</span><span class="token function">reduce</span><span class="token punctuation">((</span>acc<span class="token punctuation">,</span> val<span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">{</span>
arr<span class="token punctuation">.</span><span class="token function">splice</span><span class="token punctuation">(</span>arr<span class="token punctuation">.</span><span class="token function">indexOf</span><span class="token punctuation">(</span>val<span class="token punctuation">),</span> <span class="token number">1</span><span class="token punctuation">);</span>
<span class="token keyword">return</span> acc<span class="token punctuation">.</span><span class="token function">concat</span><span class="token punctuation">(</span>val<span class="token punctuation">);
}, [])
arr<span class="token punctuation">.</span><span class="token function">splice</span><span class="token punctuation">(</span>arr<span class="token punctuation">.</span><span class="token function">indexOf</span><span class="token punctuation">(</span>val<span class="token punctuation">),</span> <span class="token number">1</span><span class="token punctuation">);</span>
<span class="token keyword">return</span> acc<span class="token punctuation">.</span><span class="token function">concat</span><span class="token punctuation">(</span>val<span class="token punctuation">);
}, [])
: [];</span>
</pre><label class="collapse">examples</label><pre class="section card-examples language-js"><span class="token function">remove</span><span class="token punctuation">([</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">,</span> <span class="token number">4</span><span class="token punctuation">],</span> n <span class="token operator">=></span> n <span class="token operator">%</span> <span class="token number">2</span> <span class="token operator">===</span> <span class="token number">0</span><span class="token punctuation">);</span> <span class="token comment">// [2, 4]</span>
</pre></div><div class="card code-card"><div class="corner beginner"></div><div class="section card-content"><h4 id="sample">sample</h4><p>Returns a random element from an array.</p><p>Use <code>Math.random()</code> to generate a random number, multiply it by <code>length</code> and round it off to the nearest whole number using <code>Math.floor()</code>. This method also works with strings.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">sample</span> <span class="token operator">=</span> arr <span class="token operator">=></span> arr<span class="token punctuation">[</span>Math<span class="token punctuation">.</span><span class="token function">floor</span><span class="token punctuation">(</span>Math<span class="token punctuation">.</span><span class="token function">random</span><span class="token punctuation">()</span> <span class="token operator">*</span> arr<span class="token punctuation">.</span>length<span class="token punctuation">)];</span>

4
docs/math.html
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@ -152,8 +152,8 @@ own individual rating by supplying it as the third argument.
</pre></div><div class="card code-card"><div class="corner beginner"></div><div class="section card-content"><h4 id="factorial">factorial</h4><p>Calculates the factorial of a number.</p><p>Use recursion. If <code>n</code> is less than or equal to <code>1</code>, return <code>1</code>. Otherwise, return the product of <code>n</code> and the factorial of <code>n - 1</code>. Throws an exception if <code>n</code> is a negative number.</p></div><div class="copy-button-container"><button class="copy-button" aria-label="Copy to clipboard"></button></div><pre class="section card-code language-js"><span class="token keyword">const</span> <span class="token function-variable function">factorial</span> <span class="token operator">=</span> n <span class="token operator">=></span>
n <span class="token operator">&lt;</span> <span class="token number">0</span>
<span class="token operator">?</span> <span class="token punctuation">(()</span> <span class="token operator">=></span> <span class="token punctuation">{</span>
<span class="token keyword">throw new</span> <span class="token class-name">TypeError</span><span class="token punctuation">(</span><span class="token string">'Negative numbers are not allowed!'</span><span class="token punctuation">);
})()
<span class="token keyword">throw new</span> <span class="token class-name">TypeError</span><span class="token punctuation">(</span><span class="token string">'Negative numbers are not allowed!'</span><span class="token punctuation">);
})()
:</span> n <span class="token operator">&lt;=</span> <span class="token number">1</span>
<span class="token operator">?</span> <span class="token number">1</span>
<span class="token punctuation">:</span> n <span class="token operator">*</span> <span class="token function">factorial</span><span class="token punctuation">(</span>n <span class="token operator">-</span> <span class="token number">1</span><span class="token punctuation">);</span>

6
docs/object.html
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@ -178,9 +178,9 @@ o<span class="token punctuation">[</span><span class="token number">1</span><spa
target <span class="token keyword">in</span> obj
<span class="token operator">?</span> obj<span class="token punctuation">[</span>target<span class="token punctuation">]
:</span> Object<span class="token punctuation">.</span><span class="token function">values</span><span class="token punctuation">(</span>obj<span class="token punctuation">).</span><span class="token function">reduce</span><span class="token punctuation">((</span>acc<span class="token punctuation">,</span> val<span class="token punctuation">)</span> <span class="token operator">=></span> <span class="token punctuation">{</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span>acc <span class="token operator">!==</span> undefined<span class="token punctuation">)</span> <span class="token keyword">return</span> acc<span class="token punctuation">;</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token keyword">typeof</span> val <span class="token operator">===</span> <span class="token string">'object'</span><span class="token punctuation">)</span> <span class="token keyword">return</span> <span class="token function">dig</span><span class="token punctuation">(</span>val<span class="token punctuation">,</span> target<span class="token punctuation">);
},</span> undefined<span class="token punctuation">);</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span>acc <span class="token operator">!==</span> undefined<span class="token punctuation">)</span> <span class="token keyword">return</span> acc<span class="token punctuation">;</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token keyword">typeof</span> val <span class="token operator">===</span> <span class="token string">'object'</span><span class="token punctuation">)</span> <span class="token keyword">return</span> <span class="token function">dig</span><span class="token punctuation">(</span>val<span class="token punctuation">,</span> target<span class="token punctuation">);
},</span> undefined<span class="token punctuation">);</span>
</pre><label class="collapse">examples</label><pre class="section card-examples language-js"><span class="token keyword">const</span> data <span class="token operator">=</span> <span class="token punctuation">{</span>
level1<span class="token punctuation">: {</span>
level2<span class="token punctuation">: {</span>

1
snippets/checkProp.md
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@ -9,6 +9,7 @@ const checkProp = (predicate, prop) => obj => !!predicate(obj[prop]);
```
```js
const lengthIs4 = checkProp(l => l === 4, 'length');
lengthIs4([]); // false
lengthIs4([1,2,3,4]); // true

6
snippets/dig.md
View File

@ -10,9 +10,9 @@ const dig = (obj, target) =>
target in obj
? obj[target]
: Object.values(obj).reduce((acc, val) => {
if (acc !== undefined) return acc;
if (typeof val === 'object') return dig(val, target);
}, undefined);
if (acc !== undefined) return acc;
if (typeof val === 'object') return dig(val, target);
}, undefined);
```
```js

4
snippets/factorial.md
View File

@ -11,8 +11,8 @@ Throws an exception if `n` is a negative number.
const factorial = n =>
n < 0
? (() => {
throw new TypeError('Negative numbers are not allowed!');
})()
throw new TypeError('Negative numbers are not allowed!');
})()
: n <= 1
? 1
: n * factorial(n - 1);

3
snippets/pipeAsyncFunctions.md
View File

@ -11,14 +11,13 @@ const pipeAsyncFunctions = (...fns) => arg => fns.reduce((p, f) => p.then(f), Pr
```
```js
const sum = pipeAsyncFunctions(
x => x + 1,
x => new Promise(resolve => setTimeout(() => resolve(x + 2), 1000)),
x => x + 3,
async x => (await x) + 4
);
(async() => {
(async () => {
console.log(await sum(5)); // 15 (after one second)
})();
```

7
snippets/remove.md
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@ -6,13 +6,12 @@ Use `Array.prototype.filter()` to find array elements that return truthy values
The `func` is invoked with three arguments (`value, index, array`).
```js
const remove = (arr, func) =>
Array.isArray(arr)
? arr.filter(func).reduce((acc, val) => {
arr.splice(arr.indexOf(val), 1);
return acc.concat(val);
}, [])
arr.splice(arr.indexOf(val), 1);
return acc.concat(val);
}, [])
: [];
```

17
test/_30s.js
View File

@ -268,9 +268,9 @@ const dig = (obj, target) =>
target in obj
? obj[target]
: Object.values(obj).reduce((acc, val) => {
if (acc !== undefined) return acc;
if (typeof val === 'object') return dig(val, target);
}, undefined);
if (acc !== undefined) return acc;
if (typeof val === 'object') return dig(val, target);
}, undefined);
const digitize = n => [...`${n}`].map(i => parseInt(i));
const distance = (x0, y0, x1, y1) => Math.hypot(x1 - x0, y1 - y0);
const drop = (arr, n = 1) => arr.slice(n);
@ -342,8 +342,8 @@ const extendHex = shortHex =>
const factorial = n =>
n < 0
? (() => {
throw new TypeError('Negative numbers are not allowed!');
})()
throw new TypeError('Negative numbers are not allowed!');
})()
: n <= 1
? 1
: n * factorial(n - 1);
@ -988,13 +988,12 @@ const reducedFilter = (data, keys, fn) =>
}, {})
);
const reject = (pred, array) => array.filter((...args) => !pred(...args));
const remove = (arr, func) =>
Array.isArray(arr)
? arr.filter(func).reduce((acc, val) => {
arr.splice(arr.indexOf(val), 1);
return acc.concat(val);
}, [])
arr.splice(arr.indexOf(val), 1);
return acc.concat(val);
}, [])
: [];
const removeNonASCII = str => str.replace(/[^\x20-\x7E]/g, '');
const renameKeys = (keysMap, obj) =>