functionally

Functionally

Usage

npm install functionally

var F = require('functionally')

function log(msg){
    console.log(msg)
}

function greet(name){
    return 'Hello ' + name + '!'
}

var logGreeting = F.compose(log, greet)

logGreeting('Bob') //console.log('Hello Bob!')

find(fn, target)

Returns the first object in target for which fn returns a truthy value.

Example

F.find(function(obj){
    return obj.name == 'js'
}, [
    {name: 'ruby'},
    {name: 'js'},
    {name: 'php'},
    {name: 'erlang'}
])
//returns the second object in the array

The find function is curried, so you can do

var findFirst = F.find(function(value, index, target){
    if (index === 0){
        return value
    }
})

findFirst([4,5,6]) == 4

once(fn)

Returns a function that calls fn just once.

Example

var counter = 0

var inc = F.once(function(){
    counter++
})

inc()
counter == 1

inc()
inc()

counter == 1

The function returned by once returns the result of the original function. On subsequent calls, returns the same result.

maxArgs(fn, count)

If you use parseInt as the parameter to array.map, you get an undesired result

['1','2','3'].map(parseInt)
//[1, NaN, NaN]

But if you use maxArgs:

var parseInt = F.maxArgs(parseInt, 1)
['1','2','3'].map(parseInt)
//you get [1,2,3], the expected result