Hi folks: I am calling to the OpenDBX library and this library uses C constants. Suppose something like this:
enum odbxerr { ODBX_ERR_SUCCESS, #define ODBX_ERR_SUCCESS ODBX_ERR_SUCCESS ODBX_ERR_BACKEND, #define ODBX_ERR_BACKEND ODBX_ERR_BACKEND ODBX_ERR_NOCAP, #define ODBX_ERR_NOCAP ODBX_ERR_NOCAP ODBX_ERR_PARAM, .........
Then I have a function like this:
char* odbx_error( odbx_t* handle, int error )
In that case the int error es the index of the array or I can use the constant. Right now, I am using int from 0 to N. But I would like to invoke calls to that function using Smalltalk Strings that represent C constants.
For example, now I have this:
OpenDBXUnix>>apiError: handle number: err "long odbx_error(odbx_t*, int)" <cdecl: char* 'odbx_error' (ulong long) module: 'opendbx' > ^self externalCallFailed
And I call them this way for example:
OpenDBXUnix apiError: handle number: 1.
But, I would love to do:
OpenDBXUnix apiError: handle number: 'ODBX_ERR_BACKEND'.
Of course this fails because it cannot coerce and String to a long.
So, that someone know how can I do this (if I can) ?
Thanks
Mariano
Use symbolic constants (pool/class vars), i.e.,
ODBXConstants class>>initialize ODBXErrSuccess := 1. "..."
and then
OpenDBXUnix apiError: handle number: ODBXErrBackend.
Cheers, - Andreas
Mariano Martinez Peck wrote:
Hi folks: I am calling to the OpenDBX library and this library uses C constants. Suppose something like this:
enum odbxerr { ODBX_ERR_SUCCESS, #define ODBX_ERR_SUCCESS ODBX_ERR_SUCCESS ODBX_ERR_BACKEND, #define ODBX_ERR_BACKEND ODBX_ERR_BACKEND ODBX_ERR_NOCAP, #define ODBX_ERR_NOCAP ODBX_ERR_NOCAP ODBX_ERR_PARAM, .........
Then I have a function like this:
char* odbx_error( odbx_t* handle, int error )
In that case the int error es the index of the array or I can use the constant. Right now, I am using int from 0 to N. But I would like to invoke calls to that function using Smalltalk Strings that represent C constants.
For example, now I have this:
OpenDBXUnix>>apiError: handle number: err "long odbx_error(odbx_t*, int)" <cdecl: char* 'odbx_error' (ulong long) module: 'opendbx' > ^self externalCallFailed
And I call them this way for example:
OpenDBXUnix apiError: handle number: 1.
But, I would love to do:
OpenDBXUnix apiError: handle number: 'ODBX_ERR_BACKEND'.
Of course this fails because it cannot coerce and String to a long.
So, that someone know how can I do this (if I can) ?
Thanks
Mariano
Another alternative to what Andreas suggested is to reify in meaningful messages the constants, see senders of YAZODRFFILibrary>>odrCreate: in the Z3950 project at SqueakSource. Cheers,
Hernán
2009/9/30 Mariano Martinez Peck marianopeck@gmail.com:
Hi folks: I am calling to the OpenDBX library and this library uses C constants. Suppose something like this:
enum odbxerr { ODBX_ERR_SUCCESS, #define ODBX_ERR_SUCCESS ODBX_ERR_SUCCESS ODBX_ERR_BACKEND, #define ODBX_ERR_BACKEND ODBX_ERR_BACKEND ODBX_ERR_NOCAP, #define ODBX_ERR_NOCAP ODBX_ERR_NOCAP ODBX_ERR_PARAM, .........
Then I have a function like this:
char* odbx_error( odbx_t* handle, int error )
In that case the int error es the index of the array or I can use the constant. Right now, I am using int from 0 to N. But I would like to invoke calls to that function using Smalltalk Strings that represent C constants.
For example, now I have this:
OpenDBXUnix>>apiError: handle number: err "long odbx_error(odbx_t*, int)" <cdecl: char* 'odbx_error' (ulong long) module: 'opendbx' > ^self externalCallFailed
And I call them this way for example:
OpenDBXUnix apiError: handle number: 1.
But, I would love to do:
OpenDBXUnix apiError: handle number: 'ODBX_ERR_BACKEND'.
Of course this fails because it cannot coerce and String to a long.
So, that someone know how can I do this (if I can) ?
Thanks
Mariano
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