Hi Terrence,
you guess is quite good. There must be instances of the classes + and
one for type t where t is the type of the list elements if sumlength is
applied to a list with some type [t]. This implies that it works fine
for t = Int, but not for t = Int -> Int (unless you define appropriate
instances).
Look at page 59-60 of the reference manual, or at page 91 of the Clean
book (see http://www.st.cs.ru.nl/papers/cleanbook/CleanBookI.pdf).
Best, Pieter Koopman
terrence.brannon wrote:
terrence.brannon wrote:
I am confused by the pipe syntax. Where is it fully discussed with
examples?
Here's another example:
sumlength :: [t] t t -> (t,t) | +, one t
I'm guessing this is saying that both + and one must be applicable to the
argument of type t
So in some cases it seems to be saying that a certain function must be
applicable and in other cases it is saying that the datum has to be of a
certain type.
But I dont know where to find this fully described with examples, so I'm
sort of hitting in the dark :)
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