[Haskell-cafe] Constructing a datatype given just its constructor
as a string?
Donald Bruce Stewart
dons at cse.unsw.edu.au
Sun Jun 24 21:45:32 EDT 2007
> Just noticed that all my responses have been going only to
> Neil, not to the group.
> Anyway, the jist of our conversation was that it's not
> possible to create arbitrary datatypes/constructors from
> strings in Haskell. Can anyone deny/confirm?
Entirely possible. Though it would be interesting to see the code that
is to process the arbitrary types as they arrive, after deserialising.
Anyway there was a thread on this last week. One solution is to have a
symbol table mapping type reps to values of a given type, then you use
that to know which type to read from the constructor tag, resolving the
problem of not knowing what type you're reading.
More information about the Haskell-Cafe