Hi Mariano, what about the rule in Kent Beck Smalltalk best practices book, put magic numbers into a method. OpenDBUnix>>odbxErrBackend. ^ 1 OpenDBUnix apiError: handle number: OpenDBUnix odbxErrBackend. Or i you prefer also can code a mapping method like this one ( although the first solution is much more elegant ) OpenDBUnix>>errorFromString: 'ODBX_ERR_BACKEND' OpenDBUnix apiError: handle number: ( OpenDBUnix errorFromString: 'ODBX_ERR_BACKEND')

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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