2.0 Replace infix in

[jariji]

Infix in acts like almost nothing else in the language: having only letters in its name, it looks like a normal variable, but it has an unexpected infix syntax.

Some ideas

• Use in(x, xs) instead.
• Use ∈ instead of in. This is annoying to type on websites.
• Use the Haskell syntax where backticks make a function into an infix operator

> f x y = x + y
> f 1 2
3
> 1 `f` 2
3

[DNF2]

It's not so unexpected, though, since it shows up in every for loop as for i in eachindex(a) etc. I also think replacing an ascii operator with a mandatory unicode version is a non-starter.

As for other similar constructs, there's also isa.

[jariji]

Right, in and isa, I think these are the only two.

But it's not a mandatory unicode: you can do in(x, xs).

As for for i in eachindex(xs) that's not using the in operator, it's a separate syntax.