Underscore in binary literals

[Takenobu Tani]

Hi Rahul,

Thanks for the explanation.
Hmm, Is not there much need...

Thank you code example.
I will also look at lexer for my study [1].

[1]: https://phabricator.haskell.org/D22

Thank you :) ,
Takenobu


2017-09-26 21:58 GMT+09:00 Rahul Muttineni <rahulmutt at gmail.com>:

> Implementation-wise, it's no so difficult to include - the lexer needs to
> be tweaked. But it seems like a specialised use-case that will only affect
> a minority of users is probably not worthwhile as an extension to the
> language/compiler.
>
> Maybe you can try using OverloadedStrings and implement this as a library?
>
> ```
> newtype Binary = Binary Integer
>   deriving Num
>
> instance IsString Binary where
>   fromString binaryLiteral = error "Code here to parse binary literal with
> underscores"
>
> binaryVal :: Binary
> binaryVal = "1101_1110_0101"
> ```
>
> Hope that helps,
> Rahul
>
> On Tue, Sep 26, 2017 at 8:40 AM, Takenobu Tani <takenobu.hs at gmail.com>
> wrote:
>
>> Dear devs,
>>
>> GHC's BinaryLiterals extension is useful.
>> (For example, x = 0b110111000101)
>>
>> Is it difficult to include underscore(_) in the format like
>> Verilog-HDL[1] ?
>> (For example, x = 0b1101_1100_0101)
>>
>> [1]: https://inst.eecs.berkeley.edu/~cs150/fa06/Labs/verilog-ieee
>> .pdf#page=20
>>
>> Regards,
>> Takenobu
>>
>>
>> _______________________________________________
>> ghc-devs mailing list
>> ghc-devs at haskell.org
>> http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
>>
>>
>
>
> --
> Rahul Muttineni
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/ghc-devs/attachments/20170926/6e3b9393/attachment.html>