
Dear Haskell-cafe, I'm trying to use Template Haskell to generate patterns in Haskell code, but after a couple of days of trying, I have not come with a solution. I hope somebody could help me. My problem is basically that I want something like: example :: Maybe a -> a example $(j "x") = x to work correctly. The idea of this simple quoter is to generate code similar to: example :: Maybe a -> a example (Just x_123) = x_123 that is, to create the "Just" pattern, and to make "x" bind to the same element. Right now my code reads: j :: String -> Q Pat j s = return (ConP 'Just [VarP (mkName s)]) which generated a new variable "x" each time, thus unable to match with the "x" in the RHS. I have also tried with lookupValueName. Note that my problem is a bit more complicated, with variable names coming from a different source. However, I think that if I solve this problem where I can make variables in a pattern and in an expression match, I should be able to use them in my complete solution. Thanks in advance.