> On Sun, Apr 14, 2019, at 11:52 AM, Nikita Popov wrote:
>> So, there's been quite a bit of extra discussion here... unfortunately I
>> can't say that it really clarified anything, we're still circling around
>> different syntax choices, with the main contenders being fn, \ and ==>.
>> fn($x) => $x
>> fn($x, $y) => $x*$y
>> \$x => $x
>> \($x, $y) => $x*$y
>> $x ==> $x
>> ($x, $y) ==> $x*$y
>> I think the main qualities of these possibilities are:
>> * Implementation complexity: fn and \ are easy, ==> is hard (lexer hack).
>> * Availability of reduced syntax: \ an ==> have a special single-argument
>> syntax, fn doesn't.
>> * Obviousness/readability: fn and ==> are obvious, while \ is not.
>> Especially \$x => $x looks quite obscure to the uninitiated (is that a
>> variable escape, like it would be in strings?)
>> At this point I'm considering to either a) move forward with fn() as the
>> choice I'd consider most likely to gather a consensus or b) have a
>> secondary three-way vote between these three syntax choices.
> I was under the impression from your earlier comments that ==> made the lexer too unhappy to even consider. Is that not the case?
> From a usability POV, I think ==> has the edge; it's reasonably self-documenting and has a short-circuit version that is still highly readable and not confusing. It also fits the "think of it as an expression not a function call" mindset, which is important. The only downside is the implementation complexity. I think you have final call on whether that would be too-ugly implementation-wise.
> If it doesn't make the lexer too unhappy ==> is my preference, I think. \$x I'd probably get used to, even if it is a bit ugly. fn() is the "safe" option: Most verbose but keeps the lexer happy.
> --Larry Garfield
Spot on I would say!
The comment "think of it as an expression not a function call" captures
my own hesitation for the fn() syntax quite well. Anyway it's in voting,
so glad we finally got this truck moving :)