[Haskell-cafe] Data records. Default values initialisation. Reading datatype from string.

Hello, I need some help with data records. Normally I can use a `read' function to convert string to some data type e.g. `(read somestring) :: Type'. However, sometimes I'd like to read a record with some uninitialised fields. I have also set up a default values for my data record, for example: `defrec = {a=0,b=1, ..., z=0}'. Now I would like to override some values, so I have a string "defrec{l=100,r=88}", but it seems that it can't be done with read `(read "defRec{l=100,r=88}") :: defRec'. Any suggestions? Siim