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Takenobu Tani

26 Sep 2017 26 Sep '17

8:40 a.m.

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

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Rahul Muttineni

26 Sep 26 Sep

8:58 a.m.

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 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@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs

-- Rahul Muttineni

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Takenobu Tani

9:19 a.m.

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 :

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 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@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs

-- Rahul Muttineni

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Moritz Angermann

9:43 a.m.

Hi, I for one, would like to have this in more than just BinaryLiterals (which I find rather useful as well!) I’d like to see `_` in any numeric literal being simply ignored, as I find it makes writing and reading numbers in source code much easier. let i = 1_000_000 :: Int f = 1_123.456 :: Float b = 0b1100_0011 And grouping (via underscore) might be very much domain specific. (One might want to denote magnitudes or patterns.) I ended up writing a quite a bit of stupid boilerplate[1] to support readable binary notation[2]. Cheers, Moritz — [1]: https://github.com/angerman/data-bitcode/blob/c9818debd3dae774967c0507882b6b... [2]: https://github.com/angerman/data-bitcode/blob/c9818debd3dae774967c0507882b6b...

On Sep 26, 2017, at 9:19 PM, Takenobu Tani wrote:

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 : 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 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@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs

-- Rahul Muttineni

_______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs

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Ben Gamari

9:43 a.m.

Takenobu Tani writes:

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].

If you do want to try pursuing a language change do feel free to submit a proposal [1]. I would also like the ability to break up large literals. However, why limit it to BinaryLiterals? I would like the same syntax for deciaml and hexadecimal literals as well. Cheers, - Ben [1] https://github.com/ghc-proposals/ghc-proposals

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Merijn Verstraaten

9:56 a.m.

I, too, have wished for the ability to have a separator in large number literals. So a strong +1 from me. Cheers, Merijn

On 26 Sep 2017, at 15:43, Ben Gamari wrote:

Takenobu Tani writes:

...
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].

If you do want to try pursuing a language change do feel free to submit a proposal [1]. I would also like the ability to break up large literals. However, why limit it to BinaryLiterals? I would like the same syntax for deciaml and hexadecimal literals as well.

Cheers,

- Ben

[1] https://github.com/ghc-proposals/ghc-proposals _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs

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Takenobu Tani

10:05 a.m.

Dear all, Thank you very much for the response and kind explanation. After studying, I will submit to ghc-proposals :) Regards, Takenobu 2017-09-26 22:56 GMT+09:00 Merijn Verstraaten :

I, too, have wished for the ability to have a separator in large number literals.

So a strong +1 from me.

Cheers, Merijn

...
On 26 Sep 2017, at 15:43, Ben Gamari wrote:

Takenobu Tani writes:

...
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].

If you do want to try pursuing a language change do feel free to submit a proposal [1]. I would also like the ability to break up large literals. However, why limit it to BinaryLiterals? I would like the same syntax for deciaml and hexadecimal literals as well.

Cheers,

- Ben

[1] https://github.com/ghc-proposals/ghc-proposals _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs

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Takenobu Tani

30 Sep 30 Sep

2:46 a.m.

Dear devs,

Thank you very much for the response and kind explanation. After studying, I will submit to ghc-proposals :)

I submitted a ghc-proposal #76 [1]. Please feedback:) [1]: https://github.com/ghc-proposals/ghc-proposals/pull/76 Regards, Takenobu 2017-09-26 23:05 GMT+09:00 Takenobu Tani :

Dear all,

Thank you very much for the response and kind explanation. After studying, I will submit to ghc-proposals :)

Regards, Takenobu

2017-09-26 22:56 GMT+09:00 Merijn Verstraaten :

...
I, too, have wished for the ability to have a separator in large number literals.

So a strong +1 from me.

Cheers, Merijn

...
On 26 Sep 2017, at 15:43, Ben Gamari wrote:

Takenobu Tani writes:

...
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].

If you do want to try pursuing a language change do feel free to submit a proposal [1]. I would also like the ability to break up large literals. However, why limit it to BinaryLiterals? I would like the same syntax for deciaml and hexadecimal literals as well.

Cheers,

- Ben

[1] https://github.com/ghc-proposals/ghc-proposals _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs

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Niklas Hambüchen

26 Sep 26 Sep

9:43 a.m.

I'd find that quite useful for hex and binary. It's useful for distinguishing e.g. 0xffffffff and 0xfffffff which when confused accidentally and lead to big bugs. Rust has exactly this feature for all numeric literals: https://rustbyexample.com/primitives/literals.html On 26/09/17 14:40, Takenobu Tani wrote:

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)

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participants (6)

Ben Gamari
Merijn Verstraaten
Moritz Angermann
Niklas Hambüchen
Rahul Muttineni
Takenobu Tani