npm package: 101
Description: common javascript utils that can be required selectively that assume es5+
Author: Tejesh Mehta
Latest version: 1.6.3

![101](http://i.imgur.com/MFrmMt6.png)
===
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# Why another JS util library?
### 1) 101 will be maintained to minimize overlap with vanilla JS.
* 101 utils are made to work well with vanilla JS methods.
* 101 will only duplicate vanilla JS to provide Functional Programming paradigms, or if
the method is not available in a widely supported JS version (currently ES5).
* Other libraries often duplicate a lot of ES5: forEach, map, reduce, filter, sort, and more.

### 2) No need for custom builds.
* With 101, import naturally, and what you use will be bundled.
* Each util method is a module that can be required `require('101/<util>')`.
* Currently CommonJS (node, browserify, webpack, etc) is supported, I will add other module system support on request.
* Other libraries can be large, and require manually creating custom builds when optimizing for size.

### Why not release each as individual modules?
I usually agree with this philosophy; however, while in practice, adherence to the module-pattern
can become quite annoying for micro-modules (like those in 101):
* Micro-modules existance throughout a project can change very frequently, because of this one may find
themselves constantly updating their package.json (repeatedly adding and removing the same micro-modules).
* Unbundling micro-modules can lead to projects with hundreds of dependencies which can be tedious to maintain.



# Installation

`npm install 101`

# Usage

## assign (aka extend)

Just like ES6's `Object.assign`. Extend an object with any number of objects (returns original).

```js
var assign = require('101/assign');

var target = { foo: 1 };
var source1 = { bar: 1 };
var source2 = { baz: 1 };
assign(target, source1) // { foo: 1, bar: 1, baz: 1 } target extended with source objects
assign(target, source1, source2) // { foo: 1, bar: 1, baz: 1 } target extended with source objects
```

## and

Functional version of `&&`. Works great with `array.reduce`.

```js
var and = require('101/and');

and(true, false); // false
and(true, true);  // true
and(true, "foo");  // "foo"
```

## apply

Functional version of `function.apply`.
Supports partial functionality (great with array functions).

```js
var apply = require('101/apply');
[sum].map(apply(null, [1, 2, 3])); // [6] = [sum(1,2,3)] = [1+2+3]
function sum () {  /* sums all arguments */ }
apply({ prop: 'val' })(function () { return this.prop; });  // 'val'
```

## bindAll

Bind methods in an object.
You can pass an array containing the name of the methods to bind as second
argument or leave it empty to bind all the available methods.

```js
var bindAll = require('101/bind-all');
var obj = {
  init: function() {
    this.on(this.handler);
  },
  on: function(handler) {
    return handler();
  },
  handler: function() {
    console.log(this.msg);
  },
  msg: 'Hello World'
}

obj.init(); // undefined

bindAll(obj);
obj.init(); // "Hello World"

bindAll(obj, ['handler']);
obj.init(); // "Hello World"
```

## clone

It's [clone](https://www.npmjs.org/package/clone) (Only exporting this bc it is used internal to 101)

```js
var clone = require('101/clone');
var obj = {
  foo: 1,
  bar: 2
};

clone(obj); // { foo: 1, bar: 2 }
```

## compose

Functional composition method. Works great with `array.reduce`.

```js
var compose = require('101/compose');

compose(isNaN, parseInt)('nope'); // isNaN(parseInt('nope')) // true
```

## converge

Converges an array of functions into one. Works great with `compose`.

```js
var converge = require('101/converge');

converge(mul, [add, sub])(6, 2); // mul(add(6, 2), sub(6, 2)) // (6+2) * (6-2) = 36

[ {a: true, b: false}
, {a: false, b: false}
, {a: true, b: true}
].filter(converge(and , [pluck("a") , pluck("b")])); // [{a: true, b: true}]

[f, converge(g, [h, i]), j].reduce(compose); // f(g(h(j), i(j)))
```

## curry

Returns a curried function.

```js
var curry = require('101/curry');

function add(a, b) { return a + b; }

var curriedAdd = curry(add);
var add2 = curriedAdd(2);

add2(6); // 8
add2(8); // 10

function join() { return Array.prototype.slice.call(arguments).join(''); }

curry(join, 3)(1)(0)(1); // "101"
```

## defaults

Fill non-existing object values with defaults. Use it to set defaults on options. Works with
supplying default values in sub-objects as well. Supports partial functionality (great with array
functions). Mutates first argument and returns mutated argument.

```js
var defaults = require('101/defaults');
var opts = { foo: 0, bar: 1 };
var defs = { foo: 1, bar: 2, qux: 2 };

defaults(opts, defs); // returns mutated `opts` { foo: 0, bar: 1, qux: 2 }
[opts].map(defaults(defs)); // [ { foo: 0, bar: 1, qux: 2 } ]

var opts = {
  foo: {
    one: 1,
    two: 2
  }
};
var defs = {
  foo: {
    two: 20,
    three: 30
  }
};
defaults(opts, defs); // { foo: { one: 1, two: 2, three: 30 } }
```

## del

Functional version of delete obj[key] which returns the same obj without the deleted key.
Supports partial functionality (great with array functions, like map).

```js
var del = require('101/del');
var obj = {
  foo: 1,
  bar: 2
};

del(obj, 'foo'); // { bar: 2 }

// use it with array.map
[obj, obj, obj].map(del('foo')); // [{ bar: 2 }, {same}, {same}]

// supports keypaths by default
var obj = {
  foo: {
    moo: 1,
    boo: 2
  },
  bar: 3
};

del(obj, 'foo.moo'); // { foo: { boo: 2 }, bar:3 }

// pass an array of keys to be deleted 
del(obj, ['foo.moo', 'bar']) // { foo: { boo: 2 } }
```

## envIs

Functional version of `str === process.env.NODE_ENV`.
Or's multiple environments.

```js
var envIs = require('101/env-is');
// process.env.NODE_ENV = development
envIs('development');     // true
envIs('production');      // false
envIs('staging', 'production');     // false
envIs('development', 'production'); // true
```

## equals

Functional implementation of Object.is with polyfill for browsers without implementations of Object.is
Supports partial functionality (great with array functions).

```js
var equals = require('101/equals');

equals(1, 1);            // true
[1,2,3].some(equals(1)); // true
equals(1, '1');          // false
```

## exists

Simple exists function.

```js
var exists = require('101/exists');

exists('foo');     // true
exists(null);      // false
exists(undefined); // false
```

## find

Just like ES6's `array.find`.

Finds the first value in the list that passes the given function (predicate) and returns it.
If list is not provided find will return a partial-function which accepts a list as the first argument.

```js
var find = require('101/find');
var hasProps = require('101/has-properties');
var arr = [{ a: 1, b: 1 }, { b: 1 }, { c: 1 }];

var item = find(arr, hasProps({ a:1 }));
// returns { a: 1, b: 1 }
// returns null if not found

// partial-function
var partial = find(hasProps({ a: 1 }));
var item = partial(arr);
// returns { a: 1, b: 1 }
// returns null if not found
```

## findIndex

Just like ES6's `array.findIndex`.

Finds the first value in the list that passes the given function (predicate) and returns it's index.
If list is not provided findIndex will return a partial-function which accepts a list as the first argument.

```js
var findIndex = require('101/find-index');
var arr = [1, 2, 3];

var index = findIndex(arr, function (val, i, arr) {
  return val === 2;
});
// returns 1
// returns -1 if not found
```

## flip

Returns a function with flipped arguments

```js
var flip = require('101/flip');
var curry = require('101/curry');
var hasKeypaths = require('101/has-keypaths');

var hasFooBar = curry(flip(hasKeypaths))(['foo.bar']);

hasFooBar({ foo: { bar : true } }); // true


function prefix(pre, str) {
  return pre + str;
}

flip(prefix)('hello', '_'); // "_hello"
```

## groupBy
Hashes an array into groups based on the value of a provided common key.
Works nicely with `pluck` and `reduce`.

```js
var groupBy = require('101/group-by');
var arr = [
    {id: 1, foo: 'bar'},
    {id: 2, foo: 'qux'},
    {id: 3, foo: 'qux'}
];

groupBy(arr, 'foo')
/*
{
  bar: [
    {id: 1, foo: 'bar'}
  ],
  qux: [
    {id: 2, foo: 'qux'},
    {id: 3, foo: 'qux'}
  ]
}
*/
// always provide initial value when using with reduce!
arr.reduce(groupBy('foo'), {}) // assumes pluck if passed string
arr.reduce(groupBy(pluck('foo')), {}) // also accepts function
/*
{
  bar: [
    {id: 1, foo: 'bar'}
  ],
  qux: [
    {id: 2, foo: 'qux'},
    {id: 3, foo: 'qux'}
  ]
}
*/
```

## hasKeypaths

Determines whether the keypaths exist and have the specified values.
Supports partial functionality (great with array functions, and 101/find).

```js
var hasKeypaths = require('101/has-keypaths');
var obj = {
  foo: {
    bar: {
      qux: 1
    }
  }
};

hasKeypaths(obj, ['foo.bar.qux']);      // true
hasKeypaths(obj, { 'foo.bar.qux': 1 }); // true
hasKeypaths(obj, ['foo.qux']);          // false
hasKeypaths(obj, { 'foo.bar': 2 });     // false
hasKeypaths(obj, { 'foo.bar': 1, 'nope': 1 }); // false

// optional 'deep' arg, defaults to true
var barObj = { bar: 1 };
hasKeypaths(obj, { 'foo.bar': barObj });         // true
hasKeypaths(obj, { 'foo.bar': barObj }, true);   // true
hasKeypaths(obj, { 'foo.bar': barObj }, false);  // false
hasKeypaths(obj, { 'foo.bar': obj.foo }, false); // true
hasKeypaths(obj, ['foo.bar'], false);            // true, uses [hasOwnProperty vs in](http://stackoverflow.com/questions/13632999/if-key-in-object-or-ifobject-hasownpropertykey)

// use it with find, findIndex, or filter!
var arr = [obj, { b: 1 }, { c: 1 }];
find(arr, hasKeypaths({ 'foo.bar.qux':1 })); // { foo: { bar: { qux: 1 } } }
find(arr, hasKeypaths(['foo.bar.qux']));     // { foo: { bar: { qux: 1 } } }

// use it to verify options object has required properties
var opts = {
  host: 'localhost',
  port: '3333',
  user: {
    id: 5
  }
};
hasKeypaths(opts, ['host', 'port', 'user.id']); // true

```

## hasProperties

Determines whether the keys exist and, if specified, has the values.
Supports partial functionality (great with array functions, and 101/find).
NOTE: I am considering deprecating this method, bc it is so similar to has-keypaths.

```js
var hasProps = require('101/has-properties');
var obj = {
  qux: 1
};
obj['foo.bar'] = 1

hasProps(obj, ['foo', 'qux']); // true
hasProps(obj, { qux: 1 }) // true

// optional 'deep' arg, defaults to true
var barObj = { bar: 1 };
hasProps(obj, { 'foo.bar': barObj });         // true
hasProps(obj, { 'foo.bar': barObj }, true);   // true
hasProps(obj, { 'foo.bar': barObj }, false);  // false
hasProps(obj, ['foo.bar'], false);            // true, uses [hasOwnProperty vs in](http://stackoverflow.com/questions/13632999/if-key-in-object-or-ifobject-hasownpropertykey)
// use it with find, findIndex, or filter!
var arr = [{ a: 1, b: 1 }, { b: 1 }, { c: 1 }];
find(arr, hasProps({ a:1 })); // { a: 1, b: 1 }
find(arr, hasProps(['a']));   // { a: 1, b: 1 }
```

## includes

Polyfill of ES7 proposed Array.prototype.includes. Will default to Array.prototype.includes if
present.

```js
var includes = require('101/includes');
var haystack = ['a', 'b', 'c', 'd', 'e'];
includes(haystack, 'c'); // true

// optional 3rd argument, searchFrom. Begin searching the target array from a specified index.
includes(haystack, 'c', 3); // false
includes(haystack, 'c', 0); // true

// partial argument functionality
var i = includes(haystack);
i('c') // true
i('g') // false

// example composition usage:
var not = require('101/not');
var notIn = not(includes);
[1, 2, 3, 4, 5].filter(notIn([1, 2, 3])); // [4, 5]
```

## indexBy
Hashes an array of objects based on the value of a provided common key.
Works nicely with `pluck` and `reduce`.

```js
var arr = [
  {foo: 'bar'},
  {foo: 'qux'}
];

arr.reduce(indexBy('foo'), {}) // assumes pluck if passed string
arr.reduce(indexBy(pluck('foo')), {}) // also accepts function
// {bar: {foo: 'bar'}, qux: {foo: 'qux'}}
// always provide initial value when using with reduce!
arr.reduce(indexBy(pluck('foo')), {}) // {bar: {foo: 'bar'}, qux: {foo: 'qux'}}
```

## instanceOf

Functional version of JavaScript's instanceof.
Supports partial functionality (great with array functions).

```js
var instanceOf = require('101/instance-of');

['foo', 'bar', 1].map(instanceOf('string')); // [true, true, false]
```

## isBoolean

Functional version of `typeof val === 'boolean'`.
Supports partial functionality (great with array functions).

```js
var isBoolean = require('101/is-boolean');

[true, false, 1].map(isBoolean); // [true, true, false]
```

## isEmpty

Functional version of val empty object, array or object

```js
var isEmpty = require('101/is-empty');

isEmpty([]); // true
isEmpty({}); // true
isEmpty(""); // true
isEmpty(" "); // false
```

## isFunction

Functional version of `typeof val === 'function'`

```js
var isFunction = require('101/is-function');

[parseInt, function () {}, 'foo'].map(isFunction); // [true, true, false]
```

## isInteger

Check if a value is an instance of an integer.

```js
var isInteger = require('101/is-Integer');

isInteger(101); // true
isInteger(101.01); // false
```

## isNumber

Functional version of val typeof 'number'.

```js
var isNumber = require('101/is-number');

['foo', NaN, 1].map(isNumber); // [false, false, true]
```

## isObject

Functional *strict* version of val typeof 'object' (and not array or regexp)

```js
var isObject = require('101/is-object');

[{}, { foo: 1 }, 100].map(isObject); // [true, true, false]
```

## isRegExp

Check if a value is an instance of RegExp

```js
var isRegExp = require('101/is-regexp');

[new RegExp('.*'), /.*/, {}, 1].map(isRegExp); // [true, true, false, false]
```

## isString

Functional version of val typeof 'string'

```js
var isString = require('101/is-string');

['foo', 'bar', 1].map(isString); // [true, true, false]
```

## keysIn

Return an array containing all the keys of an object.
It differs from the native `Object.keys` by including also the `prototype` keys.

```js
var keysIn = require('101/keys-in');
var User = function() {
  this.msg = 'Hello World';
}
User.prototype.isLoggedIn = function() { /* example function */ }

var user = new User();
keysIn(user); // ['msg', 'isLoggedIn']
```

## last

Returns the last value of a list

```js
var last = require('101/last');

last([1, 2, 3]); // 3
last('hello');   // 'o'
```

## lens

Create a lens to access a data structure. When passed a property key as a string, it returns a function `fn(obj)` that acts as a getter for that. It also exposes `.set(value, obj)` and `.mod(fn, obj)`.

```js
var fooLens = lens('foo');
var toUpper = function(str) { return str.toUpperCase(); };
var obj = {
  foo: 'foo',
  bar: 'bar'
};

fooLens(obj); // => 'foo'
fooLens.set('moo', obj); // => { foo: 'moo', bar: 'bar' }
fooLens.mod(toUpper, obj); // => { foo: 'MOO', bar: 'bar' }
```

You may also provide getter and setter functions.

```js
var arr = ['foo', 'bar'];
var first = lens(
    function(arr) { return arr[0]; },
    function(val, arr) { var clone = arr.slice(); clone[0] = val; return clone; }
);

first(arr); // => 'foo'
first.set('moo')(arr); // => ['moo', 'bar']
first.mod(toUpper)(arr); // => ['FOO', 'bar']
```

## noop

No-op function

```js
require('101/noop'); // function () {}
```

## not

Functional version of `!`.

```js
var not = require('101/not');

not(isString)('hey'); // false
not(isString)(100);   // true
```

## omit

Immutable version of `delete obj.key`. Returns a new object without the specified keys.
Supports partial functionality (great with array functions, like map).

```js
var omit = require('101/omit');
var obj = {
  foo: 1,
  bar: 2
};

omit(obj, 'foo');          // { bar: 1 }
omit(obj, ['foo']);        // { bar: 1 }
omit(obj, ['foo', 'bar']); // { }

// use it with array.map
[obj, obj, obj].map(omit('foo')); // [{ bar: 1 }, { bar: 1 }, { bar: 1 }];
```

## or

Functional version of `||`.
Works great with `array.reduce`.

```js
var or = require('101/or');

or(true, true);   // true
or(true, false);  // true
or(false, false); // false
or("foo", false); // "foo"
```

## passAll

Muxes arguments across many functions and `&&`'s the results.
Supports partial functionality (great with array functions, like map).

```js
var passAll = require('101/pass-all');

['', 'foo', 'bar', 100].map(passAll(isString, isTruthy)); // [false, true, true, false]
```

## passAny

Muxes arguments across many functions and `||`'s the results.
Supports partial functionality (great with array functions, like map).

```js
var passAny = require('101/pass-any');

['', 'foo', 'bar', 100].map(passAny(isString, isNumber)); // [true, true, true, true]
```

## pick

Returns a new object with the specified keys (with key values from obj).
Supports regular expressions and partial functionality (great with array functions, like map).

```js
var pick = require('101/pick');
var obj = {
  foo: 1,
  bar: 2,
  qwk: {
    wrk: 1
  },
  'qwk.wrk': 2
};

pick(obj, 'foo');          // { foo: 1 }
pick(obj, RegExp('oo$'));  // { foo: 1 }
pick(obj, ['foo']);        // { foo: 1 }
pick(obj, ['foo', 'bar']); // { foo: 1, bar: 2 }

// use it with array.map
[obj, obj, obj].map(pick('foo')); // [{ foo: 1 }, { foo: 1 }, { foo: 1 }];

// supports keypaths
pick(obj, 'qwk.wrk');      // { qwk: { wrk: 1 } }
pick(obj, '["qwk.wrk"]');  // { 'qwk.wrk': 2 } }
```

## pluck

Functional version of obj[key], returns the value of the key from obj.
Supports partial functionality (great with array functions, like map).

```js
var pluck = require('101/pluck');
var obj = {
  foo: 1,
  bar: 2
};

pluck(obj, 'foo'); // 1

// use it with array.map
[obj, obj, obj].map(pluck('foo')); // [1, 1, 1]

// supports keypaths by default
var obj = {
  foo: {
    bar: 1
  },
  'foo.bar': 2
};

pluck(obj, 'foo.bar'); // 1, supports keypaths by default
pluck(obj, 'foo.bar', false); // 2, pass false to not use keypaths
```

## put

Immutable version of `obj[key] = val`. Returns a clone of the obj with the value put at the key.
Supports partial functionality (great with array functions, like map).

```js
var put = require('101/put');
var obj = {
  foo: 1,
  bar: 2
};

put(obj, 'baz', 3); // { foo: 1, bar:2, baz: 3 }
obj; // { foo: 1, bar: 2 } (not modified)

// use it with array.map
[obj, obj, obj].map(put('foo', 100)); // [{ foo: 100, bar: 2 }, {copy}, {copy}]
obj; // { foo: 1, bar: 2 } (not modified)

// supports keypaths by default
var obj = {
  bar: 2
};

put(obj, 'foo.qux', 100); // { foo: { qux: 100 }, bar: 2 }
put(obj, {
  'foo.qux': 100
  'yolo': 1
}); // { foo: { qux: 100 }, bar: 2, yolo: 1 }
obj; // { foo: 1, bar: 2 } (not modified)
```

## set

Functional version of obj[key] = val, returns the same obj with the key and value set.
Supports partial functionality (great with array functions, like map).

```js
var set = require('101/set');
var obj = {
  foo: 1,
  bar: 2
};

set(obj, 'foo'); // 1

// use it with array.map
[obj, obj, obj].map(set('foo', 100)); // [{ foo: 100, bar: 2 }, {same}, {same}]

// supports keypaths by default
var obj = {
  bar: 2
};

set(obj, 'foo.qux', 100); // { foo: { qux: 100 }, bar: 2 }
set(obj, {
  'foo.qux': 100
  'yolo': 1
}); // { foo: { qux: 100 }, bar: 2, yolo: 1 }
```

## values

Returns Array containing the values of the properties of an object

```js
var values = require('101/values');
var obj {
  foo: 'apple',
  bar: 'orange'
};

var objValues = values(obj);
objValues // ['apple', 'orange']
```

## xor

Exclusive or
Works great with `array.reduce`.

```js
var xor = require('101/xor');

xor(true, true);   // false
xor(true, false);  // true
xor(false, true);  // true
xor(false, false); // false
```

## License

MIT