Function Compositon with Pipe Operator

[aj0strow]

Basically sugar, but would be cool to compose functions with the pipeline op. Could possibly help with #5571.

f(x) = x |> factor |> keys |> length

f = factor |> keys |> length
# ERROR: no method keys(Function,)
#  in |> at operators.jl:159

I think the relevant code is

julia/base/operators.jl

Line 159 in a26f03e

|>(x, f::Function) = f(x)

.

Something like this?

|>(f1::Function, f2:Function) = x -> f1(f2(x))

Down to figure out how to write a test n such, just let me know.

[simonbyrne]

I was thinking about this the other day, the problem would be how to distinguish between f1(f2) (i.e. f1 acts on a function f2), and x -> f1(f2(x)) (the composition of f1 and f2).

I agree it would be useful though, especially if there was a way to combine all this with the do notation.

[stevengj]

you can do x -> x |> factor |> keys |> length

[stevengj]

This seems to be a duplicate of #5236.

[aj0strow]

Indeed a duplicate. Sorry!