[issue887237] Machine integers
Changes by Ezio Melotti ezio.melo...@gmail.com: -- versions: +Python 3.4 -Python 3.2 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue887237] Machine integers
Changes by Bruno Dupuis bdup...@lisael.org: -- nosy: +bruno.dupuis ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue887237] Machine integers
Changes by Daniel Urban urban.dani...@gmail.com: -- nosy: +durban ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue887237] Machine integers
Benjamin Peterson benja...@python.org added the comment: You could write a Python script to generator the methods. -- nosy: +benjamin.peterson ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue887237] Machine integers
Alexander Belopolsky belopol...@users.sourceforge.net added the comment: As far as I understand, the main concern about issue887237.diff was code duplication. There are two ways to fight it: C preprocessor tricks as in issue887237-macro.diff and code generation as done in numpy. With improved macro support in many compilers and debuggers, preprocessor approach may be preferable. However I cannot move this issue forward until those who objected to code duplication review the latest patch. Unassigning. -- assignee: belopolsky - nosy: -BreamoreBoy ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue887237] Machine integers
Mark Lawrence breamore...@yahoo.co.uk added the comment: Perhaps people could review the latest patch in view of the following. 1) Quote from Mark Dickinson msg75815 I think this would be valuable for rapid prototyping of an algorithm in Python before translating it into C. In particular, it might help with detecting some common C code bugs involving undefined behaviour---for example, overflow in signed-integer arithmetic. 2) issue1621 Do not assume signed integer overflow behavior Perhaps this could be treated as purely experimental? (This might have been suggested already, sorry if I've missed it). Whatever happens I'd be glad to help out if possible, the big asset I have compared to others is time as I only work part time. -- nosy: +BreamoreBoy ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue887237] Machine integers
Changes by Alexander Belopolsky belopol...@users.sourceforge.net: -- assignee: - belopolsky components: +Extension Modules, ctypes -Library (Lib) nosy: -Alexander.Belopolsky stage: - patch review versions: +Python 3.2 ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue887237] Machine integers
Thomas Heller thel...@ctypes.org added the comment: Code duplication is unavoidable because the goal is to give access to machine arithmetics which means (# types) x (# operations) of very similar looking functions. I considered reducing (perceived) code duplication through some pre-processor magic, but doing so would make code much harder to understand and almost impossible to debug. Carefully written macros shouldn't be hard to understand. At least there wouldn't be the risk of overlooking one of the methods when making modifications. The code duplication in Alex's patch is indeed enormous. I can see two solutions to avoid (or work around) them. Use of macros, or writing a Python script that generates the C-code. Anyway, I guess his patch is some example code, not more. (Using C++ overloaded functions or even templates would be another - but only theoretical - possibility). I would like to hear from Thomas before introducing macros in this code. I tried to follow the style of cfield.c which shows similar code duplication. There are also some questions that need to be answered before polishing the code. 1. Should mixed arithmetics be supported? 2. Should we do anything special about floating point operations? Wrapping them in PyFPE_START/STOP_PROTECT? 3. Should we support in-place operations? 4. Bitwise operations on integers? I would answer 1, 3, and 4, with 'yes'. However, this grows the code size by another dimension since we now have #types * #operation * #types. My answer for question 3 is 'I don't know'. Before I forget: It may be possible to implement ctypes number methods as a third-party module by implementing a mixin class, and replacing the c_... type definitions in Lib/ctypes/__init__.py. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue887237] Machine integers
Alexander Belopolsky alexander.belopol...@gmail.com added the comment: Attaching a patch that is equivalent toissue887237.diff, but uses preprocessor to generate repetitive code. -- Added file: http://bugs.python.org/file16466/issue887237-macro.diff ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue887237] Machine integers
Antoine Pitrou pit...@free.fr added the comment: Le Fri, 05 Mar 2010 02:21:30 +, Alexander Belopolsky rep...@bugs.python.org a écrit : Code duplication is unavoidable because the goal is to give access to machine arithmetics which means (# types) x (# operations) of very similar looking functions. I considered reducing (perceived) code duplication through some pre-processor magic, but doing so would make code much harder to understand and almost impossible to debug. Carefully written macros shouldn't be hard to understand. At least there wouldn't be the risk of overlooking one of the methods when making modifications. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue887237] Machine integers
Alexander Belopolsky alexander.belopol...@gmail.com added the comment: I would like to hear from Thomas before introducing macros in this code. I tried to follow the style of cfield.c which shows similar code duplication. There are also some questions that need to be answered before polishing the code. 1. Should mixed arithmetics be supported? 2. Should we do anything special about floating point operations? Wrapping them in PyFPE_START/STOP_PROTECT? 3. Should we support in-place operations? 4. Bitwise operations on integers? On Thu, Mar 4, 2010 at 9:29 PM, Raymond Hettinger rep...@bugs.python.org wrote: Raymond Hettinger rhettin...@users.sourceforge.net added the comment: Look at Modules/operator.c for example of an effective use of macros to minimize code duplication. -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue887237 ___ -- ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue887237] Machine integers
Changes by Alexander Belopolsky [EMAIL PROTECTED]: Added file: http://bugs.python.org/file12323/ctypes-numbermixins-1.patch ___ Python tracker [EMAIL PROTECTED] http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue887237] Machine integers
Thomas Heller [EMAIL PROTECTED] added the comment: One difficulty with the patch is that the original ctypes code contained a tp_as_number ... This can be solved by changing the order of bases for c_type classes. See attached. Cool! Why didn't I think of that myself? ___ Python tracker [EMAIL PROTECTED] http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue887237] Machine integers
Thomas Heller [EMAIL PROTECTED] added the comment: I wonder if a patch for ctypes like this (which is not yet complete) could be used to implement this, or MUST it be implemented in C? The patch contains a mixin class that implements the numeric methods. However, the actual operation takes place in Python; only the operands are converted into ctypes types first, the operand is applied to the value, and the result is converted to a ctypes instance again. One difficulty with the patch is that the original ctypes code contained a tp_as_number member where only the nb_nonzero slot was actually implemented; this prevented the mixin class to do it's work (Python didn't call the special methods. I wonder if there is a bug somewhere...). -- keywords: +patch Added file: http://bugs.python.org/file12016/ctypes-numbermixins.patch ___ Python tracker [EMAIL PROTECTED] http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
[issue887237] Machine integers
Mark Dickinson [EMAIL PROTECTED] added the comment: Is it be feasible to add arithmetic operations to the ctypes integer types? Since ctypes is now in the core, it would seem better to enhance ctypes than provide a new module. I think this would be valuable for rapid prototyping of an algorithm in Python before translating it into C. In particular, it might help with detecting some common C code bugs involving undefined behaviour---for example, overflow in signed-integer arithmetic. -- nosy: +marketdickinson ___ Python tracker [EMAIL PROTECTED] http://bugs.python.org/issue887237 ___ ___ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
