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Enumerable

Enumerable mixin.

users
  .map('friends')
  .select('age > 20')
  .map('name.first')
  .select(/^T/)

Installation

$ component install component/enumerable

Implementation

Nearly all methods utilize the to-function component, which converts the argument passed to a function. For example .map('name.first') expands to a function effectively defined as return obj.name.first, likewise .select(/^Tobi/) expands to return /^Tobi/.test(str) and so on. For details check out to-function's Readme and familiarize yourself since all of that is applicable to Enumerable.

API

mixin()

Mixin to obj.

 var Enumerable = require('enumerable');
 Enumerable(Something.prototype);

.each(fn:Function)

Iterate each value and invoke fn(val, i).

 users.each(function(val, i){

 })

.map(fn:Function)

Map each return value from fn(val, i).

Passing a callback function:

 users.map(function(user){
   return user.name.first
 })

Passing a property string:

 users.map('name.first')

.select(fn:Function|String)

Select all values that return a truthy value of fn(val, i).

 users.select(function(user){
   return user.age > 20
 })

With a property:

 items.select('complete')

.unique()

Select all unique values.

 nums.unique()

.reject(fn:Function|String|Mixed)

Reject all values that return a truthy value of fn(val, i).

Rejecting using a callback:

 users.reject(function(user){
   return user.age < 20
 })

Rejecting with a property:

 items.reject('complete')

Rejecting values via ==:

 data.reject(null)
 users.reject(toni)

.compact()

Reject null and undefined.

 [1, null, 5, undefined].compact()
 // => [1,5]

.find(fn:Function)

Return the first value when fn(val, i) is truthy, otherwise return undefined.

 users.find(function(user){
   return user.role == 'admin'
 })

.findLast(fn:Function)

Return the last value when fn(val, i) is truthy, otherwise return undefined.

 users.findLast(function(user){
   return user.role == 'admin'
 })

.none(fn:Function|String)

Assert that none of the invocations of fn(val, i) are truthy.

For example ensuring that no pets are admins:

 pets.none(function(p){ return p.admin })
 pets.none('admin')

.any(fn:Function)

Assert that at least one invocation of fn(val, i) is truthy.

For example checking to see if any pets are ferrets:

 pets.any(function(pet){
   return pet.species == 'ferret'
 })

.count(fn:Function)

Count the number of times fn(val, i) returns true.

 var n = pets.count(function(pet){
   return pet.species == 'ferret'
 })

.indexOf(obj:Mixed)

Determine the indexof obj or return -1.

.has(obj:Mixed)

Check if obj is present in this enumerable.

.reduce(fn:Function, [val]:Mixed)

Reduce with fn(accumulator, val, i) using optional init value defaulting to the first enumerable value.

.max(fn:Function|String)

Determine the max value.

With a callback function:

 pets.max(function(pet){
   return pet.age
 })

With property strings:

 pets.max('age')

With immediate values:

 nums.max()

.sum(fn:Function|String)

Determine the sum.

With a callback function:

 pets.sum(function(pet){
   return pet.age
 })

With property strings:

 pets.sum('age')

With immediate values:

 nums.sum()

.first([n]:Number|Function)

Return the first value, or first n values.

.last([n]:Number|Function)

Return the last value, or last n values.

.inGroupsOf(n:Number)

Return values in groups of n.

.at(i:Number)

Return the value at the given index.

.value()

Return the enumerable value.

License

MIT