Re: [RFC]Discuss] Syntax for Arrow Functions

On 9 June 2017 21:00:48 BST, Niklas Keller <me@kelunik.com> wrote: >2017-06-09 15:44 GMT+02:00 Sara Golemon <pollita@php.net>: > >> On Fri, Jun 9, 2017 at 7:23 AM, Björn Larsson ><bjorn.x.larsson@telia.com> >> wrote: >> > If I take the liberty in using the example above on our option >list: >> > 1. $someDict->map(fn($v) => $v * 2)->filter(fn($v) => $v % 3); >> > 2. $someDict->map(function($v) => $v * 2)->filter(function($v) => >$v % >> 3); >> > 3. $someDict->map($v ==> $v * 2)->filter($v ==> $v % 3); >> > 4. $someDict->map(($v) => $v * 2)->filter(($v) => $v % 3); >// >> > Ambiguous >> > 5. $someDict->map([]($v) => $v * 2)->filter([]($v) => $v % 3); >> > >> > Old proposals: >> > 6. $someDict->map($v ~> $v * 2)->filter($v ~> $v % 3); >> > 7. $someDict->map(lambda($v) => $v * 2)->filter(lambda($v) => $v % >3); >> > >> Something else which really pops in these examples is the effect of >> not needing to use parentheses when embedding a single-arg short >> lambda. 3 and 6 in your list read cleaner to me (due to the lack of >> parenthesis clutter). Sadly ~> has the same hacky implementation >> issues as ==>, but I think that shows a little bit of why the >HackLang >> team decided the messy lexer was worth the clearer syntax. > > >Another possible syntax (dunno whether this has already been suggested >on-list): > >$function = { $x => 2 * $x }; >$function = { ($x) => 2 * $x }; >$function = | $x => 2 * $x |; >$function = | ($x) => 2 * $x |; > >Nikita and Levi prefer it with parenthesis, I prefer it without, >because I >think it's unnecessary clutter. I already suggested the brace version, and Levi said it would conflict in the parser: https://externals.io/thread/911#email-15331 I don't know enough about parsing to comment on what workarounds would be possible. Regards, -- Rowan Collins [IMSoP]