[Haskell-cafe] Handling Postgresql array types

Tom Ellis tom-lists-haskell-cafe-2013 at jaguarpaw.co.uk
Tue Dec 30 10:01:05 UTC 2014


On Sun, Dec 28, 2014 at 06:59:26PM -0800, info at rotnetix.com wrote:
> I am curious as to how easy it will be for me to create a different mapping 
> for PGArray, so that instead of (PGArray (PGArray PGFloat8)) -> [[Double]] 
> I can do (PGArray (PGArray Float8)) -> Matrix Double.  It is not a big deal 
> to do the conversion later but if the library allows that kind of thing to 
> be easily done it can make the code more readable.

Sure, you could do it by adding a QueryRunnerDefault instance or just a
QueryRunner instance for a compound type like the FromRow instance for IIM.

Tom


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