[Haskell-cafe] lambda case (was Re: A big hurray for lambda-case (and all the other good stuff))

[adam vogt]

On Sun, Dec 30, 2012 at 10:00 PM, Brandon Allbery <allbery.b at gmail.com> wrote:
> On Sun, Dec 30, 2012 at 8:42 PM, Dan Burton <danburton.email at gmail.com>
> wrote:
>>>
>>> [featureX] is usually too powerful, it surely would be abused
>>> extensively, which would make developer's life a nightmare, unless there is
>>> only one developer and whole development takes no more than a couple of
>>> months.
>>
>>
>> This doesn't say much about why syntax extension is too powerful, nor how
>> that would lead to extensive abuse. Well, "too powerful" or not,
>> meta-programming should be more easily available at least at some layer of
>> language development without having to resort to hacking the compiler.
>
>
> I think someone's already working on this (SugarHaskell?).

Hi All,

Petr's suggestion has some similarities with this quasiquoter
<http://hackage.haskell.org/packages/archive/applicative-quoters/0.1.0.8/doc/html/Control-Applicative-QQ-ADo.html>,
at least as far as picking a different return type if some patterns
can fail. If new syntax implemented by a quasiquoter is really that
good, then these possible issues should be worth it:

- have to type [| |]
- haskell-src-exts parser called may not have the same extensions enabled as ghc
- when other new syntax is added, template haskell (and
haskell-src-meta) may not gain those features for a year or more

Regards,
Adam