12.17.2 Unpacker Objects 
The Unpacker class offers the following methods:
- 
Resets the string buffer with the given data.
- 
Returns the current unpack position in the data buffer.
- 
Sets the data buffer unpack position to position.  You should be
careful about using get_position() and set_position().
- 
Returns the current unpack data buffer as a string.
- 
Indicates unpack completion.  Raises an Error exception
if all of the data has not been unpacked.
In addition, every data type that can be packed with a Packer,
can be unpacked with an Unpacker.  Unpacking methods are of the
form unpack_type(), and take no arguments.  They return the
unpacked object.
- 
Unpacks a single-precision floating point number.
- 
Unpacks a double-precision floating point number, similarly to
unpack_float().
In addition, the following methods unpack strings, bytes, and opaque
data:
- 
Unpacks and returns a fixed length string.  n is the number of
characters expected.  Padding with null bytes to guaranteed 4 byte
alignment is assumed.
- 
Unpacks and returns a fixed length opaque data stream, similarly to
unpack_fstring().
- 
Unpacks and returns a variable length string.  The length of the
string is first unpacked as an unsigned integer, then the string data
is unpacked with unpack_fstring().
- 
Unpacks and returns a variable length opaque data string, similarly to
unpack_string().
- 
Unpacks and returns a variable length byte stream, similarly to
unpack_string().
The following methods support unpacking arrays and lists:
- 
  | unpack_list( | unpack_item) |  
 
- 
Unpacks and returns a list of homogeneous items.  The list is unpacked
one element at a time
by first unpacking an unsigned integer flag.  If the flag is 1,
then the item is unpacked and appended to the list.  A flag of0indicates the end of the list.  unpack_item is the
function that is called to unpack the items.
- 
  | unpack_farray( | n, unpack_item) |  
 
- 
Unpacks and returns (as a list) a fixed length array of homogeneous
items.  n is number of list elements to expect in the buffer.
As above, unpack_item is the function used to unpack each element.
- 
  | unpack_array( | unpack_item) |  
 
- 
Unpacks and returns a variable length list of homogeneous items.
First, the length of the list is unpacked as an unsigned integer, then
each element is unpacked as in unpack_farray() above.
Release 2.4.3, documentation updated on 29 March 2006.
 
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