On Thu, 4 Sep 2003, Sebastian Sylvan wrote:
On Thu, 4 Sep 2003, John Hughes wrote:
I wrote the system for my (Haskell!) programming course, with 170 students last year, and it is now also being used (at least) for our Java course and a cryptography course. It consists of about 600 lines of Haskell and 18 lines of C.
Just curious. What was C used for?
/One of the students in the mentioned haskell programming course...
I implemented a trivial "database", stored in ordinary files, and had to ensure mutual exclusion of database access between simultaneously running CGI scripts. Since each CGI run is short, I simply locked the entire database for the entire run. Claiming a lock on a file is easy in C (well, it takes 18 lines...), but there's nothing in the standard Haskell libraries that can do it. So I borrowed a little C code from the net, and called it via the FFI. John