Re: [Hat] How to use Control.Monad.State?

Larry, Sorry for the delay in response - I have only just seen your messages. I think your first approach, using a Makefile, was sound. The only thing missing was the specification of the package in which the module Control.Monad.State lives. I.e. you need to add "-package mtl" to the compilation commands. This is not usually necessary for a normal compilation with ghc, because the compiler has some notion of packages that are "exposed" by default. But when tracing, (a) hmake is unaware of which packages are exposed, so needs them to be listed explicitly, and (b) the hat package may depend implicitly on some packages that are not explicitly noted in its configuration, so ghc does not know to look for them. Regards, Malcolm