Hi haskellers,<br><br>I have a datatype of this sort:<br><br>data Type = Status<br> | Message<br> | Warning<br> | Error <br> | StepIn<br> | StepOut deriving (Eq, Show)<br><br>and (at this moment) two fabric-like functions:<br>
<br>makeType :: String -> Type<br>makeType c = case c of<br> "-$-" -> Status<br> "-M-" -> Message<br> "-W-" -> Warning<br>
"-E-" -> Error<br> "->>" -> StepIn<br> "<<-" -> StepOut<br> otherwise -> error "Uknown Message Type"<br>
<br>deduceType :: Integer -> Type<br>deduceType n = case n of<br> 240 -> Status<br> 64 -> Message<br> 32 -> Warning<br> 8 -> StepOut<br>
4 -> StepIn<br> 2 -> Error<br> otherwise -> error "Unknown Message Type"<br><br>how can I avoid boilerplate code at this stage? The thing that I really need is some n-type constructor, kind of a fabric for a variety of types with the possibility to add them on the fly (I have simple Integer and String here, but they could be much more sophisticated). I don't need the possibility to unpack the original value (e.g. "-$-" or 240) once the Type is created - in this case I can always have some sort of mapping to deduce it at any moment, so it will be redundant to carry it through the code explicitly<br>
<br>The example is rather short and simple, but I have some more places in code, where the same problem is observed. Is there any generic solution? Thanks in advance<br clear="all"><br>-- <br>Regards, Paul Sujkov<br>