Hi folks, I have uploaded a new package to Haskell: convertible. At its heart, it's a very simple typeclass that's designed to enable a reasonable default conversion between two different types without having to remember a bunch of functions. The return type from this conversion is "Either ConvertError a", and conversions are expected to do sanity checking (such as bounds checking when converting to types like Int), so as to produce neither garbage nor exceptions as part of the conversion process. The package also includes instances of the Convertible typeclass for working with numeric types as well as dates and times. Notably, it has code to convert between System.Time types and their Data.Time siblings, and vice versa, a capability I found annoyingly lacking in the standard library. There is also a simple wrapper function called convert, that transforms a Left result into a call to error, and returns a Right result. For HDBC v2.0, the SqlValue/SqlType system has been completely rewritten in terms of Convertible, though I expect backwards compatibility will not be broken by this change (existing code will compile and run fine). I hope to release v2.0 of the HDBC API and backends in a few days. Convertible is not for everyone; if you care whether you use truncate or round to convert a Double to an Integer, this isn't for you. Note, though, that you can import the library without its default instances, so you can define your own if you prefer. API docs and downloads at: http://hackage.haskell.org/cgi-bin/hackage-scripts/package/convertible -- John