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digitalmars.D - Voting for std.experimental.checkedint

reply Robert burner Schadek <rburners gmail.com> writes:
This is the voting thread to decide if the proposed addition to 
Phobos, std.experimental.checkedint, should be accepted.

To vote, please respond to this post. You have three options:

* Yes
* Yes with a single condition
* No

If you vote "yes" you can still mention something you'd like 
improved, but please be explicit if that problem is a non starter 
for you and you are choosing option two. If you vote no, please 
state why, though you aren't required to.

Some things to consider when making a vote:

* Is this functionality needed in Phobos?
* The API is practically permanent once the module is accepted. 
Some minor changes can be made, but a full redesign is no longer 
an option.

The voting will end 2017-01-31

The PR can be found here:
https://github.com/dlang/phobos/pull/4613

The dub package can be found here:
http://code.dlang.org/packages/checkedint_andralex

The review thread can be found here:
http://forum.dlang.org/post/mnounbaobgphbmanfaks forum.dlang.org
Jan 13
next sibling parent reply deadalnix <deadalnix gmail.com> writes:
Is the doc available somewhere in a readable form ?
Jan 13
parent reply Robert burner Schadek <rburners gmail.com> writes:
On Friday, 13 January 2017 at 12:49:53 UTC, deadalnix wrote:
 Is the doc available somewhere in a readable form ?
CyberShadow/DAutoTest build the docs, you can find the link at the end of the PR under checks
Jan 13
parent Bastiaan Veelo <Bastiaan Veelo.net> writes:
On Friday, 13 January 2017 at 13:25:10 UTC, Robert burner Schadek 
wrote:
 On Friday, 13 January 2017 at 12:49:53 UTC, deadalnix wrote:
 Is the doc available somewhere in a readable form ?
CyberShadow/DAutoTest build the docs, you can find the link at the end of the PR under checks
Readers trying to find that link on their phone should switch to the desktop version (link at the very bottom of the page.) However volatile, at the moment the docs are here: http://dtest.thecybershadow.net/artifact/website-f99d0fe6d09e288faf22f3eb515fc56e3c892179-48800882159648c96641690c7485b586/web/phobos-prerelease/std_experimental_checkedint.html Bastiaan.
Jan 16
prev sibling next sibling parent reply Jack Stouffer <jack jackstouffer.com> writes:
On Friday, 13 January 2017 at 12:39:38 UTC, Robert burner Schadek 
wrote:
 ...
Overall, the code looks good and the design looks solid. However, I have no personal use for such a module, so I can't really comment on it's design with any authority. Abstain.
Jan 14
parent reply Jonathan M Davis via Digitalmars-d <digitalmars-d puremagic.com> writes:
On Saturday, January 14, 2017 20:54:11 Jack Stouffer via Digitalmars-d 
wrote:
 On Friday, 13 January 2017 at 12:39:38 UTC, Robert burner Schadek

 wrote:
 ...
Overall, the code looks good and the design looks solid. However, I have no personal use for such a module, so I can't really comment on it's design with any authority. Abstain.
That's pretty much the boat I'm in, though I've never looked at it in depth. It's one of those things that a few folks seem to think is vital, but I have zero use for it. It's trying to solve a problem that I simply don't have. - Jonathan M Davis
Jan 16
parent reply Atila Neves <atila.neves gmail.com> writes:
On Monday, 16 January 2017 at 19:51:38 UTC, Jonathan M Davis 
wrote:
 On Saturday, January 14, 2017 20:54:11 Jack Stouffer via 
 Digitalmars-d wrote:
 On Friday, 13 January 2017 at 12:39:38 UTC, Robert burner 
 Schadek

 wrote:
 ...
Overall, the code looks good and the design looks solid. However, I have no personal use for such a module, so I can't really comment on it's design with any authority. Abstain.
That's pretty much the boat I'm in, though I've never looked at it in depth. It's one of those things that a few folks seem to think is vital, but I have zero use for it. It's trying to solve a problem that I simply don't have. - Jonathan M Davis
Same here. Atila
Jan 17
parent Guillaume Piolat <first.last gmail.com> writes:
On Tuesday, 17 January 2017 at 11:53:16 UTC, Atila Neves wrote:
 Same here.

 Atila
No interest either. Have zilch problems with integers.
Jan 17
prev sibling next sibling parent Thorsten Sommer <vektoren gmail.com> writes:
Yes
Jan 16
prev sibling next sibling parent Chris Wright <dhasenan gmail.com> writes:
On Fri, 13 Jan 2017 12:39:38 +0000, Robert burner Schadek wrote:

 This is the voting thread to decide if the proposed addition to Phobos,
 std.experimental.checkedint, should be accepted.
 
 To vote, please respond to this post. You have three options:
 
 * Yes * Yes with a single condition * No
Yes. Most of the time in my code, integer overflow is a bug. I want to defend myself against bugs. My new code will use checkedint by default (with some convenience aliases, and with regular integers as an option in the public interface). There are some minor documentation changes I would like; I have submitted a PR.
Jan 17
prev sibling next sibling parent deadalnix <deadalnix gmail.com> writes:
Alright some feedback.

It is rather disappointing that Warn and Abort only write to 
stderr. Being able to specify the sink would be great. i may want 
to log the issue or something.

There is option to throw on error.

Checked!(Checked!(int, ProperCompare), WithNaN) is rather 
inelegent. Why not Checked!(int, ProperCompare, WithNaN) ?

get() should not be inout. It returns a value type. const is fine.

Otherwise, the overall design looks pretty solid. Congrats to you 
guys. Idealy, I'd like to see these things polished, but I'm 
rather pleased to see where this is going.

I'd say yes, modulo the above.
Jan 17
prev sibling next sibling parent Meta <jared771 gmail.com> writes:
On Friday, 13 January 2017 at 12:39:38 UTC, Robert burner Schadek 
wrote:
 This is the voting thread to decide if the proposed addition to 
 Phobos, std.experimental.checkedint, should be accepted.

 To vote, please respond to this post. You have three options:

 * Yes
 * Yes with a single condition
 * No

 If you vote "yes" you can still mention something you'd like 
 improved, but please be explicit if that problem is a non 
 starter for you and you are choosing option two. If you vote 
 no, please state why, though you aren't required to.

 Some things to consider when making a vote:

 * Is this functionality needed in Phobos?
 * The API is practically permanent once the module is accepted. 
 Some minor changes can be made, but a full redesign is no 
 longer an option.

 The voting will end 2017-01-31

 The PR can be found here:
 https://github.com/dlang/phobos/pull/4613

 The dub package can be found here:
 http://code.dlang.org/packages/checkedint_andralex

 The review thread can be found here:
 http://forum.dlang.org/post/mnounbaobgphbmanfaks forum.dlang.org
Yes, with the comment that this would probably be better as a Dub package, at least for the time being. If std.experimental didn't exist I would say no outright.
Jan 17
prev sibling parent reply Robert burner Schadek <rburners gmail.com> writes:
checkedint got voted in. With 2 Yes and 2 yes with remarks.

I will set the autotester to merge.

Thank you  andralex for the hard work.
Feb 24
parent reply Dmitry Olshansky <dmitry.olsh gmail.com> writes:
On 2/24/17 4:20 PM, Robert burner Schadek wrote:
 checkedint got voted in. With 2 Yes and 2 yes with remarks.
Remarkably unpopular vote we have here. If I read it right it implies that nobody cares for checked integers.
 I will set the autotester to merge.

 Thank you  andralex for the hard work.
--- Dmitry Olshansky
Feb 24
next sibling parent Jack Stouffer <jack jackstouffer.com> writes:
On Friday, 24 February 2017 at 20:37:28 UTC, Dmitry Olshansky 
wrote:
 If I read it right it implies that nobody cares for checked 
 integers.
I guess you can say I don't personally care about them because I have no personal use case for them. But, as I said in my remarks, I understand why we should have them. Time will tell from users if this solution is workable.
Feb 24
prev sibling next sibling parent Ola Fosheim Grostad <ola.fosheim.grostad gmail.com> writes:
On Friday, 24 February 2017 at 20:37:28 UTC, Dmitry Olshansky 
wrote:
 On 2/24/17 4:20 PM, Robert burner Schadek wrote:
 checkedint got voted in. With 2 Yes and 2 yes with remarks.
Remarkably unpopular vote we have here. If I read it right it implies that nobody cares for checked integers.
It is more useful as a compiler switch, a type won't help when you call into third party libraries.
Feb 24
prev sibling parent reply rumbu <rumbu rumbu.ro> writes:
On Friday, 24 February 2017 at 20:37:28 UTC, Dmitry Olshansky 
wrote:
 On 2/24/17 4:20 PM, Robert burner Schadek wrote:
 checkedint got voted in. With 2 Yes and 2 yes with remarks.
Remarkably unpopular vote we have here. If I read it right it implies that nobody cares for checked integers.
A lot of bloat code for something extremely basic. Newbie asks: How do I check for integer overflow in D? Response: http://dtest.thecybershadow.net/artifact/website-f99d0fe6d09e288faf22f3eb515fc56e3c892179-48800882159648c96641690c7485b586/web/phobos-prerelease/std_experimental_checkedint.html * newbie runs scared. My 2 cents.
Feb 25
parent reply Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
On 02/25/2017 10:17 AM, rumbu wrote:
 A lot of bloat code for something extremely basic.
If you can do it with less code, I'm all ears. Thanks! -- Andrei
Feb 25
next sibling parent reply Vladimir Panteleev <thecybershadow.lists gmail.com> writes:
On Saturday, 25 February 2017 at 15:21:10 UTC, Andrei 
Alexandrescu wrote:
 On 02/25/2017 10:17 AM, rumbu wrote:
 A lot of bloat code for something extremely basic.
If you can do it with less code, I'm all ears. Thanks! -- Andrei
Perhaps a simpler example for the most basic use case could be added near the top. In the heat of solving a problem, encountering two pages of theory and explanation for something the usage of which should be simple might be discouraging. Basically, something like: writeln((checked(5) + 7).get); // 12 writeln((checked(10) * 1000 * 1000 * 1000).get); // Overflow on binary operator
Feb 25
parent Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
On 2/25/17 11:00 AM, Vladimir Panteleev wrote:
 On Saturday, 25 February 2017 at 15:21:10 UTC, Andrei Alexandrescu wrote:
 On 02/25/2017 10:17 AM, rumbu wrote:
 A lot of bloat code for something extremely basic.
If you can do it with less code, I'm all ears. Thanks! -- Andrei
Perhaps a simpler example for the most basic use case could be added near the top. In the heat of solving a problem, encountering two pages of theory and explanation for something the usage of which should be simple might be discouraging. Basically, something like: writeln((checked(5) + 7).get); // 12 writeln((checked(10) * 1000 * 1000 * 1000).get); // Overflow on binary operator
OK, let's do this: https://github.com/dlang/phobos/pull/5192 https://github.com/dlang/phobos/pull/5195 Thanks, Andrei
Feb 25
prev sibling parent reply rumbu <rumbu rumbu.ro> writes:
On Saturday, 25 February 2017 at 15:21:10 UTC, Andrei 
Alexandrescu wrote:
 On 02/25/2017 10:17 AM, rumbu wrote:
 A lot of bloat code for something extremely basic.
If you can do it with less code, I'm all ears. Thanks! -- Andrei
This was not about coding skills, was about usability. The module contains too many options and failure scenarios instead of a simple default behavior. Considering that in most languages with integrated overflow checking, the default behavior is throwing some kind of exception (Ada, C#, Pascal, Rust, Swift), this one must be at least highlighted at the top of the documentation.
Feb 26
parent reply Seb <seb wilzba.ch> writes:
On Sunday, 26 February 2017 at 09:41:46 UTC, rumbu wrote:
 On Saturday, 25 February 2017 at 15:21:10 UTC, Andrei 
 Alexandrescu wrote:
 On 02/25/2017 10:17 AM, rumbu wrote:
 A lot of bloat code for something extremely basic.
If you can do it with less code, I'm all ears. Thanks! -- Andrei
This was not about coding skills, was about usability. The module contains too many options and failure scenarios instead of a simple default behavior. Considering that in most languages with integrated overflow checking, the default behavior is throwing some kind of exception (Ada, C#, Pascal, Rust, Swift)
If you want a module with a lot less features, the low-level core.checkedint might be interesting for you: http://dlang.org/phobos/core_checkedint.html
 this one must be at least [be] highlighted at the top of the 
 documentation.
It is now: http://dlang.org/phobos-prerelease/std_experimental_checkedint.html If this is still unclear, please submit a PR to improve the docs! ;-)
Feb 26
next sibling parent reply Patrick Schluter <Patrick.Schluter bbox.fr> writes:
On Sunday, 26 February 2017 at 09:53:42 UTC, Seb wrote:
 On Sunday, 26 February 2017 at 09:41:46 UTC, rumbu wrote:
 [...]
If you want a module with a lot less features, the low-level core.checkedint might be interesting for you: http://dlang.org/phobos/core_checkedint.html
 [...]
It is now: http://dlang.org/phobos-prerelease/std_experimental_checkedint.html If this is still unclear, please submit a PR to improve the docs! ;-)
The runnable examples fail at compilation with /d947/f268.d(1): Error: module checkedint is in file 'std/experimental/checkedint.d' which cannot be read
Feb 26
parent Seb <seb wilzba.ch> writes:
On Sunday, 26 February 2017 at 10:34:07 UTC, Patrick Schluter 
wrote:
 On Sunday, 26 February 2017 at 09:53:42 UTC, Seb wrote:
 On Sunday, 26 February 2017 at 09:41:46 UTC, rumbu wrote:
 [...]
If you want a module with a lot less features, the low-level core.checkedint might be interesting for you: http://dlang.org/phobos/core_checkedint.html
 [...]
It is now: http://dlang.org/phobos-prerelease/std_experimental_checkedint.html If this is still unclear, please submit a PR to improve the docs! ;-)
The runnable examples fail at compilation with /d947/f268.d(1): Error: module checkedint is in file 'std/experimental/checkedint.d' which cannot be read
Yes that's expected as DPaste doesn't support dmd-nightly builds :/ There's not much I can update this - the maintainer of DPaste hasn't been very active recently. So if you want to do sth. about it, there are two ways: 1) Ping him friendly -> https://github.com/nazriel 2) Write your DPaste replacement (could be based on the dlang-tour [1]) [1] https://github.com/stonemaster/dlang-tour/issues/501
Feb 26
prev sibling parent reply Andrei Alexandrescu <SeeWebsiteForEmail erdani.org> writes:
On 2/26/17 4:53 AM, Seb wrote:
 On Sunday, 26 February 2017 at 09:41:46 UTC, rumbu wrote:
 On Saturday, 25 February 2017 at 15:21:10 UTC, Andrei Alexandrescu wrote:
 On 02/25/2017 10:17 AM, rumbu wrote:
 A lot of bloat code for something extremely basic.
If you can do it with less code, I'm all ears. Thanks! -- Andrei
This was not about coding skills, was about usability. The module contains too many options and failure scenarios instead of a simple default behavior. Considering that in most languages with integrated overflow checking, the default behavior is throwing some kind of exception (Ada, C#, Pascal, Rust, Swift)
If you want a module with a lot less features, the low-level core.checkedint might be interesting for you: http://dlang.org/phobos/core_checkedint.html
Thanks for making this point. I agree with the sentiment "you mean I need a 1 KLOC library just to check a handful of operations?" This paradox is very interesting and worth looking into. (BTW the number of lines as dscanner --sloc counts is 1261.) Indeed, the routines in core.checkedint are everything needed (in addition to some inline code for comparisons) if the purpose is to check operations individually. However, if the intent is to check for errors systematically for certain values or program fragments, that doesn't scale; before long, the code becomes a bloatfest. Not to mention the difficulty in making sure that all operations of interest have been, in fact, covered. So the next logical step is to attempt encapsulation of these checks in a type. Here is where one way or another the code bulk must increase, and the key question here is how much ability to customize you get per unit of code increase. One issue with checked integers in general, and as a standard (i.e. highly reusable) library in particular, is that they are quite project specific: what to do upon violation, and which operations to verify and which to let run at full speed. As soon as a library does something even slightly different from what's necessary, the usability and efficiency margins are so narrow, you need to throw the library away and write your own. This is very opposite from, say, writing a sorting algorithm wherein the API design is very narrow and the difficulty is in the algorithm itself. So if you want to write a highly reusable checkedint library, you must put ability to customize front, left, and center. I've started work on an article on DbI, and did a little research on other libraries. I found these: * Mozilla's CheckedInt: https://hg.mozilla.org/mozilla-central/file/tip/mfbt/CheckedInt.h, clocking at only 791 LoC (no docs and unittests). Though compact and ingenious, it makes two design decisions that I think are problematic: (a) it stores a "valid" bit (which costs an actual word) together with the integral value (https://hg.mozilla.org/mozilla-central/file/tip/mfbt/CheckedInt.h#l503), which leads to an inefficient layout and also puts all enforcement onus on the user; and (b) it separates overflow checks from the actual operations, which leads to bulky and inefficient overflow checks (see e.g. https://hg.mozilla.org/mozilla-central/file/tip/mfbt/CheckedInt.h#l256 for addition). * https://safeint.codeplex.com by Microsoft - a behemoth of a library clocking at 7055 LoC including comments. Speed is an explicit goal. It makes a number of design decisions that might not work for everyone, for example: - accepts (somewhat obliquely) implicit conversion back to the representation type, which is kind of defeating the purpose - taking the address decays to a pointer to unchecked integral (what?) - has a rigid error policy (either assert or throw) - the checks and the error handling policies are awkwardly controlled via command line instead of template parameters - binary operators don't work against two SafeInts - signed/unsigned comparisons are not checked (this is a consequence of the implicit decay) * https://github.com/robertramey/safe_numerics, meant as an addition to Boost. That's also a large lbrary (4969 lines with light comments, going up to over 10K lines with unittests, and requiring 6 other Boost libraries: MPL, Integer, Config, Concept Checking, Tribool, and Enable_if). The author also wrote a recent article (Overload Feb 2017) that describes the library: http://www.rrsd.com/software_development/safe_numerics/Overload137.pdf. The article does a great job at motivating such libraries. The facility allows good error policy customization, and allows to some extent customizing the checks being done (only for promotions). It also has a mode that is at least theoretically interesting - it expands the result of operations whenever possible to preserve correctness, and refuses to compile code that might overflow. I speculate that that feature is of very limited use; in just a couple of steps everything goes to 64 bits, and we're done. The implementation has the usual genuflections one would expect, for example: template<class T, class U> using calculate_max_t = typename boost::mpl::if_c< // clause 1 - if both operands have the same sign std::numeric_limits<T>::is_signed == std::numeric_limits<U>::is_signed, // use that sign typename boost::mpl::if_c< std::numeric_limits<T>::is_signed, std::intmax_t, std::uintmax_t >::type, // clause 2 - otherwise if the rank of the unsigned type exceeds // the rank of the of the maximum signed type typename boost::mpl::if_c< (rank< select_unsigned<T, U>>::value > rank< std::intmax_t >::value), // use unsigned type std::uintmax_t, // clause 3 - otherwise if the type of the signed integer type can // represent all the values of the unsigned type typename boost::mpl::if_c< std::numeric_limits< std::intmax_t >::digits >= std::numeric_limits< select_unsigned<T, U> >::digits, // use signed type std::intmax_t, // clause 4 - otherwise use unsigned version of the signed type std::uintmax_t >::type >::type >::type; * https://code.dlang.org/packages/checkedint by Thomas Stuart Bockman. I might be biased but it compares favorably against all of the above. A major goal of std.experimental.checkedint was to allow more customization in a smaller package. Andrei
Feb 26
parent Walter Bright <newshound2 digitalmars.com> writes:
On 2/26/2017 1:15 PM, Andrei Alexandrescu wrote:
 Indeed, the routines in core.checkedint are everything needed (in addition to
 some inline code for comparisons) if the purpose is to check operations
 individually.
The purpose of core.checkedint is to provide the smallest possible building block for doing checked integers. This is to encapsulate it so it: 1. can be made portable 2. can be recognized by the compiler with the potential for using the knowledge of the semantics of it to generate /better/faster/reliable/more correct/ code 3. is a clue to the reader of the code what the point of the odd looking expressions is As John Regehr pointed out in a series of articles, http://blog.regehr.org/archives/1139 most people do ad-hoc checking which turns out to be very fragile in the face of compiler optimizations and handling of undefined behavior.
Feb 26