Docs and examples contain outdated references to runIOE

[btubbs]

runIOE is all over the docs, examples, and comments, but no longer in the code. As someone new to this library, and still fairly new to Haskell, this leads to a lot of frustration.

If you can show me the new recommended way to make a connection, I'll grep through the codebase, update the examples, and send a pull request.

[dschalk]

As you probably discovered, "runIOE" was still present in the final version mongoDB 1 (the "1" series ended with version "1.5"), but was gone in version "2.0" and hasn't reappeared. Hackage stated its type as "runIOE :: ErrorT IOError IO a -> IO aSource" and commented, :"Run action while catching explicit error and rethrowing in IO monad."

I am experimenting with mongoDB this week and I haven't encountered any problems with the published examples when I just leave out "runIOE"; for example, by changing "pipe <- runIOE $ connect $ . . ." to "pipe <- connect $ . . ."

I doubt that there is a new recommended way to make a connection. I don't think that "runIOE" was ever declared to be deprecated. Updating the examples to make them compileable would be a valuable contribution to the Haskell community. People who are curious about Haskell aren't likely to study code that doesn't run, or to stick with a language whose ecosphere is so littered with example code that doesn't work. I'll raise the issue of the non-compiling tutorial code at mongodb/mongoDB-haskell on Github. Somebody should tell the author of Haskell Data Analysis Cookbook that he got blindsided by the change, and his book went to press with a dud mongodb example.