From: barabba <igor.sarzisartori@...>
Date: 2007-03-24T07:10:12+09:00
Subject: Re: problem in Extending ruby

On Mar 21, 5:47 pm, ravinder <ravinder.1...@gmail.com> wrote:
> I want to call C code from my ruby class. I am using SWIG for doing
> this. I am able to compile the code and also able to invoke a C function
> from ruby, but am unable to access a variable.
> I have declared the variable as follows in "test.h" file:
>
> typedef struct GenParams_s {
>     Version a_version;     /**< Version */
>     BOOL keep_ignorable;  /**< Keep Ignorable Whitespaces (Default:
> FALSE) */
>     BOOL use_strtbl;         /**< Generate String Table (Default: TRUE)
> */
>
> } GenParams;
>
> typedef enum Version_e {
>     VERSION_UNKNOWN = -1, /**< Unknown Version */
>     VERSION_10 = 0x00,    /**< 1.0 Token */
>     VERSION_11 = 0x01,    /**< 1.1 Token */
>     VERSION_12 = 0x02,    /**< 1.2 Token */
>     VERSION_13 = 0x03     /**< 1.3 Token */
>
> } Version;
>
> #define BOOL unsigned char
>
> Now I have another class "Convert.c", in which I have declared the
> functions which I want to call from ruby. One of the method has
> following signature:
>
> A_DECLARE(Error) a_conv_a2b_withlen(UTINY  *a, ULONG   a_len, UTINY **b,
> ULONG *b_len,
>                                     GenParams *params)
>
> UTINY and ULONG are declared as unsigned char and unsigned long
> respectively. I am importing "test.h" file in "Convert.c" file.
>
> Next I compile "Convert.c" file using nmake etc...(as required by SWIG).
> Now I want to access the method defined in Convert.c file, which I am
> doing as follows:
>
> require 'converter'
>
> params = GenParams.new
> convert = Converter.a_conv_a2b_withlen("a sample test", 13, "", 100,
> params)
>
> and getting following error:
> "uninitialized constant GenParams (NameError)"
>
> I'd appreciate if anyone can help me in this case or suggest me a
> pointer as to where to look.
>
> Thanks,
> Ravinder Singh
>
> --
> Posted viahttp://www.ruby-forum.com/.

May be you have to use something like Converter::GenParams.new. I
suggest you to look inside the generated file from swig to know how
the structure GenParams is converted.