Syntax for function composition

[@gavinking] I would like an operator for composing functions, but I’m not sure what actual symbol to use. I suppose => and <= could work.

function times2plus1(Integer i) = 2.times => 1.plus;

or

function times2plus1(Integer i) = 1.plus <= 2.times;

Another possibility would be @ which sorta kinda looks a little bit like the traditional symbol in mathematics if you squint. But it doesn’t make the direction of composition clear, and is less flexible than => and <= because you can’t choose the direction of composition.

Any suggestions?

[Migrated from ceylon/ceylon-spec#123]

[davidfestal]

Will we eventually consider “esoteric” compositions, like optional or spreading

don’t know about the best ascii syntax, but I’d like to have this feature.

[gavinking]

Wait wait wait, isn’t it “obvious” that the correct syntax for composition, given that a pipe is written |> must clearly be:

>|>

Since composition has a function on both ends, whereas a pipe has a function only as the RHS.

And then reversed composition, if we need it, would be:

<|<