## lodash/fp

The `lodash/fp` module is an instance of `lodash` with its methods wrapped to
produce immutable auto-curried iteratee-first data-last methods.

## Installation

In a browser:
```html
<script src='path/to/lodash.js'></script>
<script src='path/to/lodash.fp.js'></script>
```

In Node.js:
```js
// Load the fp build.
var _ = require('lodash/fp');

// Load a method category.
var object = require('lodash/fp/object');

// Load a single method for smaller builds with browserify/rollup/webpack.
var extend = require('lodash/fp/extend');
```

## Convert

Although `lodash/fp` & its method modules come pre-converted there are times when
you may want to convert another lodash package or create a customized conversion.
That’s when the `convert` module comes in handy.

```js
var convert = require('lodash/fp/convert');

// Convert by name.
var assign = convert('assign', require('lodash.assign'));

// Convert by object.
var fp = convert({
  'assign': require('lodash.assign'),
  'chunk': require('lodash.chunk')
});

// Convert by `lodash` instance.
var fp = convert(lodash.runInContext());
```

It’s even customizable.
```js
// Every option is `true` by default.
var filter = convert('filter', _.filter, {
  // Specify capping iteratee arguments.
  'cap': true,
  // Specify currying.
  'curry': true,
  // Specify fixed arity.
  'fixed': true,
  // Specify immutable operations.
  'immutable': true,
  // Specify rearranging arguments.
  'rearg': true
});

// Specify `cap` of `false` to create a function that doesn’t cap iteratee arguments.
var filter = convert('filter', _.filter, { 'cap': false });

filter(function(value, index) {
  return index % 2 == 0;
})(['a', 'b', 'c']);
// => ['a', 'c']
```

## Mapping

Immutable auto-curried iteratee-first data-last methods sound great, but what’s
that really mean for each method? Below is a breakdown of the mapping used to
convert each method.

#### Capped Iteratee Arguments

Methods that cap iteratees to one argument:<br>
<%= toFuncList(_.keys(_.pickBy(mapping.iterateeAry, _.partial(_.eq, _, 1)))) %>

Methods that cap iteratees to two arguments:<br>
<%= toFuncList(_.keys(_.pickBy(mapping.iterateeAry, _.partial(_.eq, _, 2)))) %>

The iteratee of `mapKeys` is invoked with one argument: (key)

#### Fixed Arity

Methods with a fixed arity of one:<br>
<%= toFuncList(mapping.aryMethod[1]) %>

Methods with a fixed arity of two:<br>
<%= toFuncList(mapping.aryMethod[2]) %>

Methods with a fixed arity of three:<br>
<%= toFuncList(mapping.aryMethod[3]) %>

Methods with a fixed arity of four:<br>
<%= toFuncList(mapping.aryMethod[4]) %>

#### Rearranged Arguments

Methods with a fixed arity of two have an argument order of:<br>
<%= toArgOrder(mapping.aryRearg[2]) %>

Methods with a fixed arity of three have an argument order of:<br>
<%= toArgOrder(mapping.aryRearg[3]) %>

Methods with a fixed arity of four have an argument order of:<br>
<%= toArgOrder(mapping.aryRearg[4]) %>

Methods with custom argument orders:<br>
<%= _.map(mapping.methodRearg, function(orders, methodName) {
  return ' * `_.' + methodName + '` has an order of ' + toArgOrder(orders);
}).join('\n') %>

Methods with unchanged argument orders:<br>
<%= toFuncList(_.keys(mapping.skipRearg)) %>

The methods `partial` & `partialRight` accept an array of arguments to partially
apply as their second parameter.

#### New Methods

Methods created to accommodate Lodash’s variadic methods:<br>
<%= toFuncList(_.keys(mapping.remap)) %>

#### Aliases

There are <%= _.size(mapping.aliasToReal) %> method aliases:<br>
<%= _.map(mapping.aliasToReal, function(realName, alias) {
  return ' * Added `_.' + alias + '` as an alias of `_.' + realName + '`';
}).join('\n') %>