There is no good solution to your problem. But one way to have
both the type A and the type B as you define them is to put them
in separate modules and then use qualified names for the `test'
function.
-- Lennart
On Jan 24, 2007, at 06:12 , jamin1001 wrote:
Hi, I am new at Haskell and have some basic questions.
Is there any way to do this more effectively? This causes the GHC
compile error "Multiple declarations of Main.test":
data A = A {test :: Int}
data B = B {test :: Int}
The Haskell 98 report in 4.2.1 under Labelled Fields says
"A label cannot be shared by more than one type in scope. Field names
share the top level namespace with ordinary variables and class
methods
and must not conflict with other top level names in scope."
So then how should this be done? What if I want to do something like
data Chair = Chair {pos:: Int, color :: Int}
data Table = Table {pos:: Int, color :: Int}
Also, could someone tell me why this doesn't compile in GHC:
data Test = A {a::Int} | B {a::Int, b::Int}
data Test2 = C {c::A}
(Test2 line): Not in scope: type constructor or class 'A'
Is there a way to qualify identical field names? What are some
standard
practices for dealing with this?
Thanks,
Jamin Ohmoto-Frederick
--
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questions-tf3080392.html#a8558522
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