Regular expressions as Haskell Type Generators?
Hello, I am wondering if it would be worth while (and possible) to allow the definition of types by regular expressions, e.g. data Date = Date #RegExp([0-9][0-9]-[0-9][0-9]-[0-9][0-9][0-9][0-9]) or easier with some auxiliary constructs. Clearly there would be some drawbacks with the use of standard String-operations or type checking. But in praxi it may be absolutely relevant. Or is some work already done in this direction? Ciao, Steffen
Steffen Mazanek <Steffen.Mazanek@UniBw-Muenchen.de> writes:
I am wondering if it would be worth while (and possible) to allow the definition of types by regular expressions, e.g.
data Date = Date #RegExp([0-9][0-9]-[0-9][0-9]-[0-9][0-9][0-9][0-9])
or easier with some auxiliary constructs.
Not sure I follow this. Why not declare Date = Date String (or whatever format), making the constructor private? Then you could of course export date-constructing functions that maintain any invariants you like. -kzm -- If I haven't seen further, it is by standing in the footprints of giants
participants (2)
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ketil＠ii.uib.no -
Steffen Mazanek