Julia: Inconsistency between `if` and `elseif` parsing

[Keno]

This is legal syntax:

false
end

but this is not:

false
elseif
true
end

(missing condition in elseif). It seems like either both should be allowed or both disallowed.

[lobingera]

i got in several places the comment: Julia syntax is correct, if the parser accepts it (no, there is no formal syntax definition). So why not just accepting this?

[JeffBezanson]

The way we encode the syntax, and what we want the syntax to be, are totally separate issues. It's perfectly possible to specify an undesirable syntax in BNF.

[JeffBezanson]

I suppose we should deprecate if<newline>.

[StefanKarpinski]

I suspect you can just make it an error – I really doubt a lot of people are using this syntax.

[Keno]

There are definitely uses of it in packages as I had disallowed this in JuliaParser and it came up while running against all packages, so a deprecation is in order.

[PallHaraldsson]

For this (and in general), is JuliaParser.jl thought of? I do not see a commit here (or a label for it, similar to "backport to 0.4"..).