Re: Permitting trailing commas for record syntax ADT declarations

Ah, just look at all these brace-and-semicolon languages, and how they thrive, and how many beginners have mastered them... #include int main () { ; /* It is sunny today, so I am in the mood for a leading semi. */ ; /* Still not in the mood to start work. */ int i; ; for (i=0; i < 5; i++) { printf("%d", i); }; /* Mmh, do you need to put a semi after the closing brace? */ /* Let's put one, just to be sure. */ /* TODO: more code */; } import Data.Foldable (forM_) main = do { ; -- It is sunny today, so I am in the mood for a leading semi. ; -- Still not in the mood to start work. ; forM_ [0..4] $ \ i -> do { print i ;} ;} -- Mmh, do you need to put a semi befor the closing brace? -- Let's put one, just to be sure. On 25.09.2014 09:13, Iavor Diatchki wrote:

Hello,

My 2c: I don't think that supporting trailing commas is worth the additional complexity to the compiler and the language.

I work with Haskell on a daily basis, and I honestly don't think that this is going to simplify my job in any way. On the other hand, it seems like it it will make it more complex to write tools that process Haskell, and to explain the syntax of the language to beginners.

-Iavor

On Wed, Sep 24, 2014 at 12:38 PM, Alexander Berntsen mailto:alexander@plaimi.net> wrote:

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On 24/09/14 08:50, Edward Kmett wrote: > I'm personally of the "it should be a language extension like > everything else" mindset Yeah, I'm going the Pragma route.

> If we limit it to record-like notions, and import/export lists, > then we don't have to deal with conflicts with TupleSections and > while it is inconsistent to have tuples behave differently, than > other comma-separated lists, I'd really rather retain tuple > sections, which I use somewhat heavily, than lose them to mindless > uniformity over how we handle comma-separated lists. I'm implementing it for things where I 100% subjectively feel it makes sense. This does *not* include tuples, for the reason you mention.

When I get the time, I will make a Wiki page outlining what I'm changing and my motivation for doing it. We can then have a discussion about where to draw the line.

I need to figure out a more elegant solution than tweaking the parser for each individual item. If someone knows their way around this code, please talk to me on IRC/SIP/XMPP/whatever. Just email me for contact info. I'll be busy today with a haskell workshop, but I plan on spending the rest of the week on this business. - -- Alexander alexander@plaimi.net mailto:alexander@plaimi.net https://secure.plaimi.net/~alexander -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/

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