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142 lines
3.9 KiB
Plaintext
142 lines
3.9 KiB
Plaintext
## lodash/fp
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The `lodash/fp` module is an instance of `lodash` with its methods wrapped to
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produce immutable auto-curried iteratee-first data-last methods.
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## Installation
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In a browser:
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```html
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<script src='path/to/lodash.js'></script>
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<script src='path/to/lodash.fp.js'></script>
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```
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In Node.js:
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```js
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// Load the fp build.
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var fp = require('lodash/fp');
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// Load a method category.
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var object = require('lodash/fp/object');
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// Load a single method for smaller builds with browserify/rollup/webpack.
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var extend = require('lodash/fp/extend');
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```
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## Mapping
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Immutable auto-curried iteratee-first data-last methods sound great, but what
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does that really mean for each method? Below is a breakdown of the mapping used
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to convert each method.
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#### Capped Iteratee Arguments
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Methods that cap iteratees to one argument:<br>
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<%= toFuncList(_.keys(_.pickBy(mapping.iterateeAry, _.partial(_.eq, _, 1)))) %>
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Methods that cap iteratees to two arguments:<br>
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<%= toFuncList(_.keys(_.pickBy(mapping.iterateeAry, _.partial(_.eq, _, 2)))) %>
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The iteratee of `mapKeys` is invoked with one argument: (key)
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#### Fixed Arity
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Methods with a fixed arity of one:<br>
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<%= toFuncList(mapping.aryMethod[1]) %>
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Methods with a fixed arity of two:<br>
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<%= toFuncList(mapping.aryMethod[2]) %>
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Methods with a fixed arity of three:<br>
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<%= toFuncList(mapping.aryMethod[3]) %>
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Methods with a fixed arity of four:<br>
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<%= toFuncList(mapping.aryMethod[4]) %>
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#### Rearranged Arguments
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Methods with a fixed arity of two have an argument order of:<br>
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<%= toArgOrder(mapping.aryRearg[2]) %>
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Methods with a fixed arity of three have an argument order of:<br>
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<%= toArgOrder(mapping.aryRearg[3]) %>
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Methods with a fixed arity of four have an argument order of:<br>
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<%= toArgOrder(mapping.aryRearg[4]) %>
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Methods with custom argument orders:<br>
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<%= _.map(mapping.methodRearg, function(orders, methodName) {
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return ' * `_.' + methodName + '` has an order of ' + toArgOrder(orders);
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}).join('\n') %>
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Methods with unchanged argument orders:<br>
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<%= toFuncList(_.keys(mapping.skipRearg)) %>
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The methods `partial` & `partialRight` accept an array of arguments to partially
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apply as their second parameter.
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#### New Methods
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Methods created to accommodate Lodash’s variadic methods:<br>
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<%= toFuncList(_.keys(mapping.remap)) %>
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#### Aliases
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There are <%= _.size(mapping.aliasToReal) %> method aliases:<br>
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<%= _.map(mapping.aliasToReal, function(realName, alias) {
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return ' * `_.' + alias + '` is an alias of `_.' + realName + '`';
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}).join('\n') %>
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## Chaining
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The `lodash/fp` module **does not** convert chain sequence methods. See
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[Izaak Schroeder’s article](https://medium.com/making-internets/why-using-chain-is-a-mistake-9bc1f80d51ba)
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for more details.
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## Convert
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Although `lodash/fp` & its method modules come pre-converted, there are times
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when you may want to customize the conversion. That’s when the `convert` method
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comes in handy.
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```js
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// Every option is `true` by default.
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var _fp = fp.convert({
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// Specify capping iteratee arguments.
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'cap': true,
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// Specify currying.
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'curry': true,
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// Specify fixed arity.
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'fixed': true,
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// Specify immutable operations.
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'immutable': true,
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// Specify rearranging arguments.
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'rearg': true
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});
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// The `convert` method is available on each method too.
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var mapValuesWithKey = fp.mapValues.convert({ 'cap': false });
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// Here’s an example of disabling iteratee argument caps to access the `key` param.
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mapValuesWithKey(function(value, key) {
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return key == 'a' ? -1 : value;
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})({ 'a': 1, 'b': 1 });
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// => { 'a': -1, 'b': 1 }
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```
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// Manual conversions are also possible with the `convert` module.
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```js
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var convert = require('lodash/fp/convert');
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// Convert by name.
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var assign = convert('assign', require('lodash.assign'));
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// Convert by object.
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var fp = convert({
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'assign': require('lodash.assign'),
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'chunk': require('lodash.chunk')
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});
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// Convert by `lodash` instance.
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var fp = convert(lodash.runInContext());
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```
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