Well, I totally disagree with this. One of the main benefits of currying is the ability to chain function calls together. For example, in F# this is typically done with the |> operator:

    let result =
        input
            |> foobinade a b
            |> barbalyze c d

Or, if we really want to name our partial function before applying it, we can use the >> operator instead:

    let f = foobinade a b >> barbalyze c d
    let result = f input

Requiring an explicit "hole" for this defeats the purpose:

    let f = barbalyze(c, d, foobinade(a, b, $))
    let result = f(input)

Or, just as bad, you could give up on partial function application entirely and go with:

    let result = barbalyze(c, d, foobinade(a, b, input))

Either way, I hope that gives everyone the same "ick" it gives me.

▲ emih 7 hours ago | parent | next [-]

You can still do this though:

  let result = (barbalyze(c, d, $) . foobinade(a, b, $)) input

Or if you prefer left-to-right:

  let result = input
    |> foobinade(a, b, $)
    |> barbalyze(c, d, $)

Maybe what isn't clear is that this hole operator would bind to the innermost function call, not the whole statement.

▲ twic 6 hours ago | parent | next [-]

Even better, this method lets you pipeline into a parameter which isn't the last one:

  let result = input
    |> add_prefix_and_suffix("They said '", $, "'!")

	▲	raincole 6 hours ago \| parent [-]
		Yeah, especially in F#, a language that means to interpolate with .Net libraries (most not written with "data input at last" mindset.) now I'm quite surprised that F# doesn't have this feature.

▲ Smaug123 4 hours ago | parent | prev | next [-]

This is essentially how Mathematica does it: the sugar `Foo[x,#,z]&` is semantically the same as `Function[{y}, Foo[x,y,z]]`. The `&` syntax essentially controls what hole belongs where.

▲ raincole 6 hours ago | parent | prev [-]

Wow, this convinced me. It's so obviously the right approach when you put it this way.

▲ skybrian 6 hours ago | parent | prev | next [-]

For pipelines in any language, putting one function call per line often works well. Naming the variables can help readability. It also makes using a debugger easier:

  let foos = foobinate(a, b, input)
  let bars = barbakize(c, d, foos)

Other languages have method call syntax, which allows some chaining in a way that works well with autocomplete.

	▲	RHSeeger 3 hours ago \| parent [-]
		> Naming the variables can help readability It can, or it can't; depending on the situation. Sometimes it just adds weight to the mental model (because now there's another variable in scope).

▲ 7 hours ago | parent | prev [-]

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