Sort of random, but something in the <#CJLTWPH7S|c...

# arrow

[Robert Menke]

Sort of random, but something in the #compose channel made me think of this. Do you think the arrow stdlib should include something like compose or andThen as utility functions?

//left to right
infix fun <A, B, C> ((A) -> B).andThen(right : (B) -> C) : (A) -> C = {
    arg -> right(invoke(arg))
}

//right to left
infix fun <A, B, C> ((B) -> C).compose(right : (A) -> B) : (A) -> C = {
    arg -> invoke(right(arg))
}

[streetsofboston]

I think they already are part of (a) Arrow library…

[Robert Menke]

oh are they?

[Robert Menke]

hmm must have missed that in the docs

[streetsofboston]

https://github.com/arrow-kt/arrow/blob/master/modules/core/arrow-syntax/src/main/kotlin/arrow/syntax/function/composition.kt

[streetsofboston]

Judging from that, in the arrow-syntax lib…?

[Robert Menke]

Thanks!

[streetsofboston]

And other ones can be found in is parent directory (eg currying and such 🙂 )
https://github.com/arrow-kt/arrow/tree/master/modules/core/arrow-syntax/src/main/kotlin/arrow/syntax/function

[pakoito]

these were brought from Funktionale, so thank @dh44t!!!

[dh44t]

😅