Proposal: ArgumentDo

Carter Schonwald carter.schonwald at gmail.com
Thu Jul 7 17:44:49 UTC 2016


the fact that its perilously close to looking like *1 typo* away from a
parser error about record syntax makes me
*-1000* now

thanks for pointing this out!

On Thu, Jul 7, 2016 at 1:32 PM, Brandon Allbery <allbery.b at gmail.com> wrote:

> Didn't they already say they disliked record syntax for exactly that
> reason?
>
> On Thu, Jul 7, 2016 at 1:23 PM, David Feuer <david.feuer at gmail.com> wrote:
>
>> What makes
>>
>> f do{x} do{y}
>>
>> any harder to read than similar record syntax?
>>
>> f Foo{foo=3} Foo{foo=4}
>>
>> On Thu, Jul 7, 2016 at 1:15 PM, Carter Schonwald
>> <carter.schonwald at gmail.com> wrote:
>> > agreed -1,
>> > ambiguity is bad for humans, not just parsers.
>> >
>> > perhaps most damningly,
>> >>
>> >>
>> >> f do{ x } do { y }
>> >
>> >
>> > is just reallly really weird/confusing to me, and as the proposal itself
>> > says at the end as the cons:
>> >
>> >
>> >> It's harder to read than the alternative.
>> >>
>> >> Creating a language extension to get rid of a single character is
>> overkill
>> >> and unnecessary.
>> >>
>> >> You can already get rid of the $ by just adding parentheses.
>> >
>> > which kinda kills any benefit in my mind. thats a HUGE complexity vs
>> > alternative ratio. I'm all in favor of doing engineering work to
>> *improve*
>> > our parser error messages and suggestions, but not stuff that
>> complicates
>> > parsing for humans  as well as machines
>> >
>> >
>> > On Wed, Jul 6, 2016 at 9:50 PM, Evan Laforge <qdunkan at gmail.com> wrote:
>> >>
>> >> On Wed, Jul 6, 2016 at 10:39 AM, Bardur Arantsson <
>> spam at scientician.net>
>> >> wrote:
>> >> > On 07/04/2016 12:31 PM, Akio Takano wrote:
>> >> >> Hi glasgow-haskell-users,
>> >> >>
>> >> >> I have written a wiki page about a proposed extension called
>> >> >> ArgumentDo. It's a small syntactic extension that allows "do"
>> >> >> expressions, lambdas and a few other kinds of expressions to be used
>> >> >> as function arguments, without parentheses.
>> >> >>
>> >> >> https://ghc.haskell.org/trac/ghc/wiki/ArgumentDo
>> >> >>
>> >> >> Any feedback is appreciated. In particular, since the idea has
>> >> >> received mixed support (see the "Discussion" section on the wiki
>> >> >> page), I'd like to make sure that there is enough support for this
>> >> >> feature to justify an implementation in GHC.
>> >> >>
>> >> >
>> >> > -1
>> >> >
>> >> > Reasons have already been given in previous threads on this. However,
>> >> > I'd point especially to the fact that people don't *agree* that this
>> is
>> >> > more readable as a very strong point against -- regardless of whether
>> >> > any one individual thinks it's more readable or not. The point is the
>> >> > there seems to be a lot of disagreement -- that indicates to me that
>> >> > this cannot by definition be a "clear win"[1]. Disclosure: I
>> personally
>> >> > find it less readable because of the implicitness. Implicitness which
>> >> > has a non-trivial probability of affecting semantics is bad in my
>> book.
>> >> > Frankly, if it came to it, I'd rather just remove $ and deal with the
>> >> > parentheses.
>> >>
>> >> I'm -1 because I think there are already too many styles.  So I don't
>> >> agree with the general sentiment that the parser should accept lots of
>> >> stuff and to rely on style guides to specify something, because in
>> >> practice everyone has their own style guide.
>> >>
>> >> I trained myself to see juxtaposition as highest precedence (which
>> >> newcomers still struggle over) and it's confusing to see juxtaposition
>> >> that has higher precedence because one of them is a keyword.  In the
>> >> same way I'm confused by 'f a { b = c }', but it's too late to change
>> >> that one.  I suppose this is already on the wiki page in the "cons"
>> >> section.
>> >> _______________________________________________
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>> >> Glasgow-haskell-users at haskell.org
>> >> http://mail.haskell.org/cgi-bin/mailman/listinfo/glasgow-haskell-users
>> >
>> >
>> >
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>> >
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>
>
>
> --
> brandon s allbery kf8nh                               sine nomine
> associates
> allbery.b at gmail.com
> ballbery at sinenomine.net
> unix, openafs, kerberos, infrastructure, xmonad
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>
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