README

cpartial
  call C functions with some arguments predefined
  cpartial is free software. It has a very liberal license. See COPYING or [1].

What is cpartial?
  cpartial is a version of Python's `partial` function for C code. Info on
  Python's partial function can be found at [2]. The primary use-case for a
  partial function is one where you have an external library which expects a
  callback function with a certain number of arguments and an implementation of
  the callback function requires additional arguments.

Example:
  The C library qsort function expects a function with the signature:
      int compare (const void * a, const void * b);
  The compare function you have requires some userdata, e.g.:
      int compare (void * userdata, const void * a, const void * b);
  You may accomplish this with the partial_quick function. See Format Strings
  below for info on the character strings used here.
      partial_quick(
          NULL,
          "v pTT*", &qsort,
          "i ipp", &compare, 1,
          array, array_length, sizeof(array_element),
          userdata);
  The first argument is an address to put the result of the library function
    into. Since qsort is void, it is ignored. (NULL)
  The second and third arguments define the library function. An asterix is
    used to specify where to put the callback function. ("v pTT*", &qsort)
  The fourth and fifth arguments define the callback function.
    ("i ipp", &compare)
  The sixth argument defines how many args to set by default to the callback
    function. (1)
  The next arguments are the arguments for the library function.
    (array, array_length, sizeof(array_element))
  The last arguments are the defaults for the callback function. (userdata)
  You may see a working example of this in the example.c file.

Format Strings:
  Format Strings may be used in place of manual function definitions by using
  any of the following functions:
      partial_sdef_fromstr, partial_fdef_fromstr, partial_fromstr
  Whitespace in these strings is ignored. The following characters specify
  the types of function arguments or returns or structure members. Capitals
  define unsigned types and lowercase define signed types.
    Void type (for function returns only):
        void     'v'
    Variable-size types:
        char     'c'
        short    's'
        int      'i'
        long     'l'
        float    'f'
        double   'd'
        void *   'p'
        size_t   'T'
    Static-size types:
        int8_t   'b'
        int16_t  'h'
        int32_t  'j'
        int64_t  'q'

Notes:
[1] http://opensource.org/licenses/BSD-3-Clause
[2] https://docs.python.org/2/library/functools.html#functools.partial