Commit Graph

62 Commits

Author SHA1 Message Date
Guido van Rossum 74679b455f Support float and double in non-native formats.
These use the ANSI/IEEE standard, which is also used by XDR;
so the _xdr module may become obsolete.
1997-01-02 22:21:36 +00:00
Guido van Rossum 60c50614e1 Added better handling of unsigned longs -- a Python long returned by
unpack('L', ...) is now acceptable to pack('L', ...).
1996-12-31 16:29:52 +00:00
Guido van Rossum 3aa27fd315 Fix the first bugs... treatment of 0 count was wrong, and memchr()
should be memset().
1996-12-31 02:10:45 +00:00
Guido van Rossum f7e6b4b388 Pretty much rewritten to fulfull several long-standing wishes:
-- The whole implementation is now more table-driven.

-- Unsigned integers.  Format characters 'B', 'H', 'I' and 'L'
mean unsigned byte, short, int and long.  For 'I' and 'L', the return
value is a Python long integer if a Python plain integer can't
represent the required range (note: this is dependent on the size of
the relevant C types only, not of the sign of the actual value).

-- A new format character 's' packs/unpacks a string.  When given a
count prefix, this is the size of the string, not a repeat count like
for the other format characters; e.g. '10s' means a single 10-byte
string, while '10c' means 10 characters.  For packing, the string is
truncated or padded with null bytes as appropriate to make it fit.
For unpacking, the resulting string always has exactly the specified
number of bytes.  As a special case, '0s' means a single, empty
string (while '0c' means 0 characters).

-- Various byte order options.  The first character of the format
string determines the byte order, size and alignment, as follows:

First character		Byte order		size and alignment

	'@'		native			native
	'='		native			standard
	'<'		little-endian		standard
	'>'		big-endian		standard
	'!'		network (= big-endian)	standard

If the first character is not one of these, '@' is assumed.

Native byte order is big-endian or little-endian, depending on the
host system (e.g. Motorola and Sun are big-endian; Intel and DEC are
little-endian).

Native size and alignment are determined using the C compiler's sizeof
expression.  This is always combined with native byte order.

Standard size and alignment are as follows: no alignment is required
for any type (so you have to use pad bytes); short is 2 bytes; int and
long are 4 bytes.  In this mode, there is no support for float and
double.

Note the difference between '@' and '=': both use native byte order,
but the size and alignment of the latter is standardized.

The form '!' is available for those poor souls who can't remember
whether network byte order is big-endian or little-endian.

There is no way to indicate non-native byte order (i.e. force
byte-swapping); use the appropriate choice of '<' or '>'.
1996-12-31 01:41:25 +00:00
Barry Warsaw 30695fa3cd Renamed. 1996-12-12 23:32:31 +00:00
Guido van Rossum d266eb460e New permission notice, includes CNRI. 1996-10-25 14:44:06 +00:00
Jack Jansen 971e1df3df Quick hack so PowerPC macs can access system structures 1995-02-02 14:29:10 +00:00
Guido van Rossum 524b588553 Added 1995 to copyright message.
Setup.in: clarified Tk comments somewhat.
structmodule.c: use memcpy() instead of double precision assignment.
1995-01-04 19:10:35 +00:00
Guido van Rossum b6775db241 Merge alpha100 branch back to main trunk 1994-08-01 11:34:53 +00:00
Guido van Rossum 9bfef44d97 * Changed all copyright messages to include 1993.
* Stubs for faster implementation of local variables (not yet finished)
* Added function name to code object.  Print it for code and function
  objects.  THIS MAKES THE .PYC FILE FORMAT INCOMPATIBLE (the version
  number has changed accordingly)
* Print address of self for built-in methods
* New internal functions getattro and setattro (getattr/setattr with
  string object arg)
* Replaced "dictobject" with more powerful "mappingobject"
* New per-type functio tp_hash to implement arbitrary object hashing,
  and hashobject() to interface to it
* Added built-in functions hash(v) and hasattr(v, 'name')
* classobject: made some functions static that accidentally weren't;
  added __hash__ special instance method to implement hash()
* Added proper comparison for built-in methods and functions
1993-03-29 10:43:31 +00:00
Guido van Rossum 90ddb7b5cb unpack() now returns a tuple, not a list 1992-08-19 16:44:15 +00:00
Guido van Rossum 0297512a08 struct: pack/unpack binary structs; fcntl: fcntl(), ioctl(). 1992-08-17 08:55:12 +00:00