Generating C parser

When run with --name <name> --generate cparser options Yoda generates two files (header and .c one) with

1. A structure with options. The structure name is <name>_yopts, each option/argument described in the .yoda file has a respective member on it.

Member name is the long option name or the opt_<short_name> one if the long one is absent. Dashes are changed with underscores.

Types correspond to .yoda file -- int are mapped to int, string and path to char *, bool to bool. If an option is string and has choices, the member named <name>_code is generated which is filled with YOPT_... constants.

If an option is pile-d the member is a pointer on an array of respective types and the number of elements in it is put in the <name>_nr member.

2. A parsing routine called <name>_yopts_parse. When called with argc and argv reports on of codes:

YOPTS_PARSE_OK means that parsing was successful, YOPTS_PARSE_ERR means there was an error parsing options, YOPTS_PARSE_SPECIAL means, that some special option was given in the command line (--help or --version).

The help text is printed automatically.

You can declare your own functions names yopt_print and yopt_realloc to provide to this .c file your way of printing messages or reallocating memory. By default libc's printf and realloc are used.