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digitalmars.D.learn - Is there a 128-bit integer in D?

reply Saurabh Das <saurabh.das gmail.com> writes:
I see that 'cent' and 'ucent' are reserved for future use but not 
yet implemented. Does anyone have a working implementation of 
these types?

Alternatively, is there an any effort towards implementation of 
arbitrary-sized integers in Phobos?

Thanks,
Saurabh
May 21 2016
next sibling parent reply Stefan Koch <uplink.coder googlemail.com> writes:
On Saturday, 21 May 2016 at 09:43:38 UTC, Saurabh Das wrote:

 I see that 'cent' and 'ucent' are reserved for future use but 
 not yet implemented. Does anyone have a working implementation 
 of these types?

 Alternatively, is there an any effort towards implementation of 
 arbitrary-sized integers in Phobos?

 Thanks,
 Saurabh


There is BigInt in phobos.
May 21 2016
parent tcak <1ltkrs+3wyh1ow7kzn1k sharklasers.com> writes:
On Saturday, 21 May 2016 at 09:56:51 UTC, Stefan Koch wrote:

 On Saturday, 21 May 2016 at 09:43:38 UTC, Saurabh Das wrote:

 I see that 'cent' and 'ucent' are reserved for future use but 
 not yet implemented. Does anyone have a working implementation 
 of these types?

 Alternatively, is there an any effort towards implementation 
 of arbitrary-sized integers in Phobos?

 Thanks,
 Saurabh


 There is BigInt in phobos.


I think cent and ucent could be implemented as ulong is possible 
to be used on 32-bit systems by adding extra assembly 
instructions. This way, when (and if) 128-bit systems are 
developed, compiler would be updated only.
May 22 2016
prev sibling next sibling parent reply Jonathan M Davis via Digitalmars-d-learn writes:
On Saturday, May 21, 2016 09:43:38 Saurabh Das via Digitalmars-d-learn wrote:

 I see that 'cent' and 'ucent' are reserved for future use but not
 yet implemented. Does anyone have a working implementation of
 these types?


The keywords are reserved for future use not in current use. So, no, there
are no 128-bit integer types in D currently. It's just that we left the door
open for ourselves to add them later without breaking programs due to having
to create a new keyword.


 Alternatively, is there an any effort towards implementation of
 arbitrary-sized integers in Phobos?


We've had that for years. It's BigInt in std.bigint.

- Jonathan M Davis
May 21 2016
parent Saurabh Das <saurabh.das gmail.com> writes:
On Saturday, 21 May 2016 at 21:51:34 UTC, Jonathan M Davis wrote:

 On Saturday, May 21, 2016 09:43:38 Saurabh Das via 
 Digitalmars-d-learn wrote:

 I see that 'cent' and 'ucent' are reserved for future use but 
 not yet implemented. Does anyone have a working implementation 
 of these types?


 The keywords are reserved for future use not in current use. 
 So, no, there are no 128-bit integer types in D currently. It's 
 just that we left the door open for ourselves to add them later 
 without breaking programs due to having to create a new keyword.


 Alternatively, is there an any effort towards implementation 
 of arbitrary-sized integers in Phobos?


 We've had that for years. It's BigInt in std.bigint.

 - Jonathan M Davis


Thankyou. I'll have a look at that.

Saurabh
May 21 2016
prev sibling parent reply Nicholas Wilson <iamthewilsonator hotmail.com> writes:
On Saturday, 21 May 2016 at 09:43:38 UTC, Saurabh Das wrote:

 I see that 'cent' and 'ucent' are reserved for future use but 
 not yet implemented. Does anyone have a working implementation 
 of these types?

 Alternatively, is there an any effort towards implementation of 
 arbitrary-sized integers in Phobos?

 Thanks,
 Saurabh


There is a recursive arbitrary sized integer implementation 
floating around somewhere. Perhaps try dub for some math 
libraries.
May 22 2016
parent reply Guillaume Piolat <first.last gmail.com> writes:
On Sunday, 22 May 2016 at 07:40:08 UTC, Nicholas Wilson wrote:

 On Saturday, 21 May 2016 at 09:43:38 UTC, Saurabh Das wrote:

 I see that 'cent' and 'ucent' are reserved for future use but 
 not yet implemented. Does anyone have a working implementation 
 of these types?

 Alternatively, is there an any effort towards implementation 
 of arbitrary-sized integers in Phobos?

 Thanks,
 Saurabh


 There is a recursive arbitrary sized integer implementation 
 floating around somewhere. Perhaps try dub for some math 
 libraries.


https://github.com/d-gamedev-team/gfm/blob/master/integers/gfm/integers/wideint.d
May 22 2016
parent reply Saurabh Das <saurabh.das gmail.com> writes:
On Sunday, 22 May 2016 at 09:07:32 UTC, Guillaume Piolat wrote:

 On Sunday, 22 May 2016 at 07:40:08 UTC, Nicholas Wilson wrote:

 On Saturday, 21 May 2016 at 09:43:38 UTC, Saurabh Das wrote:

 I see that 'cent' and 'ucent' are reserved for future use but 
 not yet implemented. Does anyone have a working 
 implementation of these types?

 Alternatively, is there an any effort towards implementation 
 of arbitrary-sized integers in Phobos?

 Thanks,
 Saurabh


 There is a recursive arbitrary sized integer implementation 
 floating around somewhere. Perhaps try dub for some math 
 libraries.


 https://github.com/d-gamedev-team/gfm/blob/master/integers/gfm/integers/wideint.d


wideint was exactly what I was looking for! Thank you so much :)

Saurabh
May 22 2016
parent reply Era Scarecrow <rtcvb32 yahoo.com> writes:
On Sunday, 22 May 2016 at 09:39:45 UTC, Saurabh Das wrote:

 On Sunday, 22 May 2016 at 09:07:32 UTC, Guillaume Piolat wrote:

 https://github.com/d-gamedev-team/gfm/blob/master/integers/gfm/integers/wideint.d


 wideint was exactly what I was looking for! Thank you so much :)


  I WANT! If this does the job, I want it as part of the Phobos 
library!!
May 22 2016
parent reply Guillaume Piolat <first.last gmail.com> writes:
On Sunday, 22 May 2016 at 09:47:54 UTC, Era Scarecrow wrote:

 On Sunday, 22 May 2016 at 09:39:45 UTC, Saurabh Das wrote:

 On Sunday, 22 May 2016 at 09:07:32 UTC, Guillaume Piolat wrote:

 https://github.com/d-gamedev-team/gfm/blob/master/integers/gfm/integers/wideint.d


 wideint was exactly what I was looking for! Thank you so much 
 :)


  I WANT! If this does the job, I want it as part of the Phobos 
 library!!


This request again ;)
I don't know how this works, someone has to propose it, clean it 
up and respond to feedback I guess.
May 22 2016
next sibling parent Era Scarecrow <rtcvb32 yahoo.com> writes:
On Sunday, 22 May 2016 at 12:03:16 UTC, Guillaume Piolat wrote:

 I don't know how this works, someone has to propose it, clean 
 it up and respond to feedback I guess.


  Glancing briefly at the source, it appears (from what I saw) 
it's heavily based on doubling the size of a lower type (2 64's 
to equal a 128, etc). This means to get the next level up you 
double again. So if I read it right for example, the opIncrease 
does this almost verbatim:

   opIncrease() { //aka ++
     low++;
     if (low == 0) //overflow detection
       high++;
   }

  Going from native up one level is easy enough, but to do a 256 
type it would do the same from a lower level. Meaning the int256 
type does opIncrease on 2 int128 types, which break down to the 
native long type. Making a 256 or 512 silently creates all the 
lower ones until it can lower to a native type as the starting 
point.


  More importantly is if they fully act as built-in types with 
their declarations, except (for maybe auto promotion of course, 
although that might work too). The only two operations that are 
going to be slow no matter how you slice it are multiply and 
divide. If you don't use multiply or divide, your code will be 
fast regardless how many levels it goes.
May 22 2016
prev sibling parent Seb <seb wilzba.ch> writes:
On Sunday, 22 May 2016 at 12:03:16 UTC, Guillaume Piolat wrote:

 On Sunday, 22 May 2016 at 09:47:54 UTC, Era Scarecrow wrote:

 On Sunday, 22 May 2016 at 09:39:45 UTC, Saurabh Das wrote:

 On Sunday, 22 May 2016 at 09:07:32 UTC, Guillaume Piolat 
 wrote:

 https://github.com/d-gamedev-team/gfm/blob/master/integers/gfm/integers/wideint.d


 wideint was exactly what I was looking for! Thank you so much 
 :)


  I WANT! If this does the job, I want it as part of the Phobos 
 library!!


 This request again ;)
 I don't know how this works, someone has to propose it, clean 
 it up and respond to feedback I guess.



1) Open PR for initial review
2) Select review manager (from the inital reviewers)
3) Open NG thread and add the addition to the queue 
(http://wiki.dlang.org/Review_Queue)
4) Hope for positive feedback

In the last month there was a tendency to only accept successful 
dub packages, so it might make sense to separate this into its 
own dub package and clean it up. This will also make it easier 
for other people to find.
May 23 2016