[issue4258] Use 30-bit digits instead of 15-bit digits for Python integers.

Doc/library/sys.rst

 
 :mod:`sys` --- System-specific parameters and functions
 =======================================================
 
 .. module:: sys
    :synopsis: Access system-specific parameters and functions.
 
 
 This module provides access to some variables used or maintained by the
 interpreter and to functions that interact strongly with the interpreter. It is
@@ skipping 395 matching lines @@
       else:
           # use an alternative implementation or warn the user
           ...
 
    This is called ``hexversion`` since it only really looks meaningful when viewed
    as the result of passing it to the built-in :func:`hex` function.  The
    ``version_info`` value may be used for a more human-friendly encoding of the
    same information.
 
 
+.. data:: int_info
+
+   A struct sequence that holds information about Python's

[Martin v. Löwis, 2009/02/17 22:39:18]

I don't think the sequence interface is really important here. There should be a
way to easily define regular struct-like classes (with no sequence interface).
Perhaps structseq could be modified to drop sequence interface, and new
structseqs should turn it off usually.

[dickinsm, 2009/02/18 17:06:33]

Agreed.  All that's important here is the attribute access.

+   internal representation of integers.  The attributes are read only.
+
+   +-------------------------+----------------------------------------------+
+   | attribute               | explanation                                  |
+   +=========================+==============================================+
+   | :const:`bits_per_digit` | number of bits held in each digit.  Python   |
+   |                         | integers are stored internally in base       |
+   |                         | ``2**int_info.bits_per_digit``               |
+   +-------------------------+----------------------------------------------+
+   | :const:`sizeof_digit`   | size in bytes of the C type used to          |
+   |                         | represent a digit                            |
+   +-------------------------+----------------------------------------------+
+
+
 .. function:: intern(string)
 
    Enter *string* in the table of "interned" strings and return the interned string
    -- which is *string* itself or a copy. Interning strings is useful to gain a
    little performance on dictionary lookup -- if the keys in a dictionary are
    interned, and the lookup key is interned, the key comparisons (after hashing)
    can be done by a pointer compare instead of a string compare.  Normally, the
    names used in Python programs are automatically interned, and the dictionaries
    used to hold module, class or instance attributes have interned keys.
 
@@ skipping 357 matching lines @@
    framework.
 
 
 .. data:: winver
 
    The version number used to form registry keys on Windows platforms. This is
    stored as string resource 1000 in the Python DLL.  The value is normally the
    first three characters of :const:`version`.  It is provided in the :mod:`sys`
    module for informational purposes; modifying this value has no effect on the
    registry keys used by Python. Availability: Windows.