Use << and >> for functional composition

[tfga]

Idea: follow Elm's lead and use >> and << for function composition.

-- Why? What's wrong with the current syntax?

Two things:

• Inconsistency.
  <- is not the opposite of ->:

  • -> means "this is a function"
  • <- means composition

  There's no symmetry.

• You can compose in only one direction (right to left).

-- But... if we did that, what would be the syntax for bit shifting?

Well, this is a matter for debate. I have a few suggestions:

• >>> and <<<
• shift> and <shift

Or we could follow Elm's steps again and simply not have them!

(Seriously: when was the last time you used bit shifting in a high-level language? I used to do it when I programmed in C. In 10 years of Java, I used it once. And never in JS or Python).

[XertroV]

What about <<< and >>>? That's what I define composition as in my purescript prelude.

Also if << and >> are already bit shifts probs best not to make a breaking change.

I picked up a bunch of nice stuff from elm, like composition and the <| style for the traditional $. But those ideas aren't from elm (that example is F# I think).

Re elm: 0.18 to 0.19 broke my respect for Elm. Removal of custom operators is a sign of the condescending nature of Elm, IMO, and doesn't help the language grow and develop.

Oh, and I use both shifts and composition, but my use case is atypical. Though never used bit shifts in dg.

[tfga]

What about <<< and >>>?

Well, it's better than the current situation, I guess. But, still: in a language like dg, composition is probably used way more than bit-shifting. I'd argue that the most used feature should have the shortest syntax (think == and = in C; :: and : in Elm).

(...) probs best not to make a breaking change.

But wouldn't it be worth it?

Besides, breaking backwards compatibility -- that's what experimental / in development languages do. Look at how many times Elm did it. And Rust (pre-1.0).

How large is dg's user base? Of these users, how many use bit shifting? Is there a way to get some estimate on these numbers?

I'm guessing that (1) dg doesn't have a lot of users and (2) of those, (almost) nobody uses bit-shifting.

But those ideas aren't from elm (that example is F# I think)

Yes, |> and <| were "borrowed" from F#.

[pyos]

Seriously: when was the last time you used bit shifting in a high-level language?

Well, almost all of my pinned projects use bit shifts, I think? dg itself for what I guess you could call C FFI (constructing flags in CPython objects), dogeweb for websockets, webmcast for EBML... Recently I've been writing mainly Kotlin, and the bit shifts I had there were for JVM spec-defined structures. They're practically required when dealing with file formats and protocols, though I guess this is not really enough to give them dedicated special operators.

But, still: in a language like dg, composition is probably used way more than bit-shifting.

Is it? Unlike languages specifically designed for that, you need to use bind for currying anyway, so maybe you're better off just writing pointful code...

[sullyj3]

Flow uses <. and .>.