Should it not just remove the empty brackets? Why would you use empty brackets anyway?

@RX14 I believe I and we don't write empty parenthesis by hand, but it is useful for code generated by program.

@makenowjust but do empty brackets change the meaning of the program? I can't see a way they do so shouldn't they just be removed?

@RX14 It has the result value nil. For example foo = () is valid program, but when () is removed, of course foo = is invalid.

@makenowjust Ah I see, yes this makes sense now.

Another point is that an editor integration that continously formats shouldn't remove them.

I think I copied () from Ruby, but I don't see the point about it. foo = () shouldn't be a valid program either. I'd say we remove empty parentheses from the language, they have no use.

@asterite How do you think about expressions list inside parenthesis like (foo; bar)? Is it needed? I think it is needless if () is needless.

For multi expression one needs multiple expressions :-)

So (1; 2) is allowed, (1) is allowed, but () shouldn't parse. I added that at one point because Ruby does that, but I don't think it makes much sense. Not even for code generation.

Multiple expressions is needed, really? I think all multiple expressions can be converted to begin ... end block. Mostly multiple expressions makes code hard to read. Instead of using multiple expressions, I prefer clearer way (i.e. using temporally variable).

A somewhat usefully application would be joining some expressions in a macro, like:

macro exprs(*exprs)
  ({{ exprs.join(";").id }}).to_s
end

exprs(1, 2 + 3)
exprs

If an empty () is valid and evaluates as nil there is no need to handle the case exprs.size == 0. Tough I don't have a real world use case for this.

@makenowjust begin and end adds much clutter, just having parenthesis could be better readable for short expressions

@straight-shoota

begin and end adds much clutter, just having parenthesis could be better readable for short expressions

Please give me a real example. I thought it a day, but I couldn't find it.
For example foo + (bar; baz) looks good parenthesis multiple expressions use case. But you should consider more deeply. When we need to write this code, foo, bar and baz have side effects surely (because we expect foo, bar and baz are evaluated in a sequential order, and if not we can rewrite it more clearly like bar; foo + baz). In this case such a tricky code isn't preferred. We should write a clearer code like foo = foo(); bar; baz = baz(); foo + baz.

Important points are two:

1. All multiple expressions are used with some side effects (internal state modification, network I/O and etc).
2. We should treat side effects carefully. They may make many bugs.

Thank you.

Every expressions have no side effect, this discussion can be thrown out, though we can't see Hello, World! on our console.

Hi, could be this a final solution to #4590?

It is intended as such see fix #4590 in the title.

In fact, no multiple expressions with parenthesis is used in compiler source codes, standard library and all samples in this repository. Where is real world use case?

Let's remove () from the language as @asterite suggested. Closing this. PRs to remove () are welcome :).

Why not merge this clearly useful fix and then decide the fate of the syntax

@mverzilli ping

@RX14 @ysbaddaden @bcardiff @matiasgarciaisaia this is ready to merge IMO.

@mverzilli Thank you ❤️