On May 31, 2008, at 10:07 AM, Felix Klock wrote: > > On May 30, 2008, at 10:56 PM, Peter Keller wrote: > >> Hello, >> >> I have another question, if I may ask: >> >> in my sqlite3 library, I have this: >> >> (define-c-info (include<> "sqlite3.h") >> (const SQLITE_INTEGER int "SQLITE_INTEGER") >> (const SQLITE_FLOAT int "SQLITE_FLOAT") >> (const SQLITE_BLOB int "SQLITE_BLOB") >> (const SQLITE_TEXT int "SQLITE_TEXT")) >> >> and then later something like this: >> >> (define sqlite3-column >> (lambda (stmt colid) >> (case (sqlite3-column-type stmt colid) >> ((SQLITE_INTEGER) >> (sqlite3-column-int stmt colid)) >> ((SQLITE_TEXT) >> (sqlite3-column-text stmt colid)) >> (else >> 'oops)))) ;; <- obviously this is still test code! >> >> It looks like the SQLITE_INTEGER and SQLITE_TEXT in the sqlite3- >> column >> function are not available to me (as the code simply doesn't work and >> I get 'oops all the time) while in the library codes. If I replace >> them >> with the real constants 1 and 3 respectively, or use SQLITE_INTEGER >> and >> SQLITE_TEXT in a piece of code which imports the sqlite3 library, >> then >> sqlite3-column behaves properly. >> >> Any ideas? > > Are you sure you mean to use Scheme's case special form in the above? > > That is, is (sqlite3-column-type stmt colid) going to produce a > Symbol, or an Integer? If it produces a Symbol, then your case > expression might work. If it produces an Integer, then you will never > get anything other than 'oops back.
One more thing: if you do want to get symbols instead of integers, there is another library, foreign-cenums, that is a derivative of the foreign-ctools library but provides C enum values as symbols rather than integers. (It does this by internally keeping a table mapping between the integers produced by define-c-info and the symbols you provide to the define-c-enum or define-c-enum-set special forms. The code isn't anything terribly special and so you may be better off sticking with define-c-info, but I thought I should point it out just in case you do want to use symbols instead of global variables or integers for the SQLITE constants.) -Felix _______________________________________________ Larceny-users mailing list Larceny-users@lists.ccs.neu.edu https://lists.ccs.neu.edu/bin/listinfo/larceny-users
