On May 23, 2011, at 10:57 AM, Daniël de Kok wrote: > I started with an Haskell implementation of the very same program using the lbfgs module, but for large data sets it's not very memory-efficient if you want Haskell'ish data structures. It's far nicer to use FFI, and write an enumerator to construct data in C from a nice Haskell representation. s/enumerator/iteratee/