Wasn t aware of this channel so reposting my question here `

Question

Wasn t aware of this channel so reposting my question here ```I have just started looking at Kotlin I have been using F on NET for a while now and I am liking Kotlin I am missing pipe operator in Kotlin though is there any plan to bring the pipe operator to Kotlin ```

raulraja · Answer

I m not aware of any efforts to bring that and to be fair that style of composition is not widely used in Kotlin Arrow used to have pipe but we removed in 0 13 because it didn t get much use <https github com arrow kt arrow core blob 0 11 0 arrow syntax src main kotlin arrow syntax function pipe kt>

elizarov · Answer

Kotlin has two features that mike piping much less needed 1 Kotlin has extensions which usually let you pipe things directly in a natural ` call` style e g `collection filter map ` no need for a pipe here 2 Kotlin has ` let` scope function that covers the case for non extension functions e g `collection first let println it `

wakingrufus · Answer

Roman s answer is 100 but for the sake of understanding < Sandeep Chandra> are you imagining something like ```infix fun lt A B gt A `|` nextOp A gt B B return nextOp this fun test Int return `|` String length `|` repeat `|` String length ```

wakingrufus · Answer

which cleans up to ```fun test Int return let String length let repeat let String length ``` and then ```fun test Int return length let repeat length ``` in ideomatic kotlin

Sandeep Chandra · Answer

Have a look at the following snippet ```let square x = x x 1 100 | gt List map square```

Sandeep Chandra · Answer

here I have declared a function called `square` and a list of numbers from 1 100 and then I call the List map passing in `square` function The pipe operator passes list of numbers to List map the map function takes 2 arguments With pipe operator the value `piped` is passed as last argument to the function

raulraja · Answer

< Sandeep Chandra> if you mean tacit point free style in Kotlin that would look like ```fun square x Int = x x val result = 1 100 map square ``` It gets more complex as your functions are polymorphic and callable references have more than one type arg in my experience but similar style can be used with them

raulraja · Answer

If you want to see the limits of more complex use cases try to pass `fold` or similar with more than one type argument as callable reference value to another function In most cases you d have to ascribe the types manually of the calling function so it takes exactly the shape it expects

raulraja · Answer

But the pipe operator does in essence what it did in arrow take a function result and pass it to the next one Kotlin does not abstract over function arity so for this to work with any name maybe `| gt ` as a library you d still need to declare N variations of the operator for as high of a function arity you want to support

Marius Kotsbak · Answer

It is for functional programming without object orientation

elizarov · Answer

Kotlin has extension functions for that They have nothing to do with object orientation and are great for writing functional code