support one liners with #? braces syntax

[timotheecour]

1 liners are very useful for REPL, otherwise cmd recall is kind of broken.

braces syntax allow arbitrary nim code to fit in 1 line.

eg:
>>> proc fun(a:int): auto {return a*2}

implementation:
using undocumented(?) ``#? braces` syntax

eg:
foo.nim

#? braces

proc main() {
  echo "Hello"
}

when (isMainModule) {
  main()
}

this mode could be enabled via a meta option, see #6, eg :brace=on or :brace=off

[ghost]

@AndreiRegiani I think this should be closed because syntax skins were removed from Nim (devel), so they'll not be available in the next Nim stable version.

[AndreiRegiani]

@Yardanico Thanks for the insight!

@timotheecour from your example, currently we can do it:

>>> proc fun(a: int): auto = return a*2
>>> fun(10)
20 : int

Can also do multiple statements using ;

>>> echo 1; echo 2; echo 3
1
2
3

e.g.

>>> proc moreFun(a, b: int): auto = echo 1; echo 2; echo 3; return a * b
>>> moreFun(2, 5)
10 : int

it seems we don't need syntax skins, right?

[ghost]

@AndreiRegiani well, you wouldn't be able to write two procedures on one line, but I don't think someone will try that.

[juancarlospaco]

I think with arrow function from future you can write 2 proc on 1 line.

I didnt know skins gonna be removed.

[ghost]

@juancarlospaco future module was renamed to sugar because it's just sugar. And no, you can't write two procs on one line with it.

[juancarlospaco]

This should be closed, the braces skin is dead.