On Fri, 2009-10-09 at 14:56 -0500, Patrick Brannan wrote:
Hello,
I'm getting back into Haskell after an absence of a few years. I'm in the process of trying to connect to postgresql with hdbc-postgresql on a Windows XP box.
Seemingly, things installed without a problem, but at the command prompt I get the following:
Prelude> :module Database.HDBC Database.HDBC.PostgreSQL module `Database.HDBC.PostgreSQL' is not loaded
If I run ghci this way with package options here's what I get:
C:\work\haskell\HDBC-postgresql-2.1.0.0>ghci -package HDBC -package HDBC-postgresql
You are running it from within the source tree of the package itself. Local sources take precedence over ones from packages. So you load the -package HDBC-postgresql, but when you ask GHCi for :module Database.HDBC.PostgreSQL it is looking at the local file Database/HDBC/PostgreSQL.hs, and you cannot switch context to a module that isn't yet loaded, hence the error. If what you want is to load the package, then start in a different directory so the local sources do not get in the way. If what you want is to load the local sources then use :load (:l) rather than :module (:m). The :load command loads local source files. The :module switches context between loaded modules (modules from packages are already loaded). Duncan