OpenSystemsLab / struct.nim

Python-like 'struct' for Nim

struct.nim

Python-like 'struct' for Nim

This library is still under development, use it as yourown risk!

Format String

Byte Order

Character	Byte order
@	native
=	native
<	little-endian
>	big-endian
!	network (= big-endian)

Notes:

• Unlike Python -byte-order can specified once as first character, with this implementation, you can change byte-order anywhere and anytime you want

Format Characters:

integerintegerintegerinteger

Format	C Type	Python Type	Nim Type	Size (bytes)
x	pad byte	no value
b	char	string of length 1	char	1
?	_Bool	bool	bool	1
h	short	integer	int16	2
H	usigned short	integer	uint16	2
i	int	integer	int32	4
I	unsigned int	integer	uint32	4
q	long long	integer	int64	8
Q	unsigned long long	integer	uint64	8
f	float	float	float32	4
d	double	float	float64	8
s	char[]	string	string

Notes:

• Format character can has a number prefix, you can use "3?" instead of "???" for pack/unpack three bool value
• For string , number prefix is the length of value

Usage

# >>> from struct import *
import struct

# >>> pack('hhi', 1, 2, 3)
var output =  pack("hhi", 1, 2, 3)

# alternative way to pack
# output = pack("hhi", newStructInt(1), newStructInt(1), newStructInt(3))

# >>> unpack('hhi', '\x00\x01\x00\x02\x00\x00\x00\x03')
var result = unpack("hhi", output);
echo result[0].getShort
echo result[1].getShort
echo result[2].getInt