Can some one please fill me in on why existential types are not
part of Haskell 98? Probably this is answered in some paper/statement
that I can read some where? I sort of understand them (* I am still
learning haskell. WOrking through S.T's book right now *) but
not enough perhaps to
Actually, IIRC, _|_ is actually a member of _all_ types.
--ag
"S. Alexander Jacobson" wrote:
On Tue, 28 Sep 1999, Adrian Hey wrote:
So (a b) = (b a) is invalid
has type
::Boolean-Boolean-Boolean
_|_ is not of type Boolean. So, if you pass a value of type _|_,
you have
I am trying to write some primitives to make it easy to manipulate haskell
datatypes without knowing what they are.
However the following class:
class MetaData a where
constructorName::a-String
mapArgs::(MetaData b,MonadPlus c) = (b-c)-a-[c]
results in the error
Illegal type
Why not Haskell I?
(as the first "standard" form of the language)...
--Artie
)
/tmp/ghc18014.hc:2265: `rl_line_buffer' undeclared (first use this function)
/tmp/ghc18014.hc:3479: warning: assignment makes pointer from integer
without a cast
e
TIA
--Artie
Arthur GoldAustin, Texas
Arthur GoldAustin, Texas
---
| [EMAIL PROTECTED] [EMAIL PROTECTED] |
---
--
-- Verbing weirds language. --
--
, 53111 Bonn, Deutschland, 0049/228/656860
Keywords: Freeform Curves Surfs, Generative Modeling, 4D Animation
FG Computergrafik: Institut f. Informatik III
Universitaet Bonn Tel: (0228) 73-4315/-4292, Fax: -4382
Roemerstr. 164, Mail: [EMAIL PROTECTED]
flow is often much more
complex.
As a result, purely functional, lazy data structures can be a little tough
to get one's head around.
--Artie
Arthur Gold Austin, Texas
** [EMAIL PROTECTED] [EMAIL PROTECTED] **
General recursion is the `go to' of functional programming
ense to
me intuitively).
Was this a conscious design decision?
...and if so, why?
Thanks.
--Artie
Arthur Gold Austin, Texas
---
| [EMAIL PROTECTED][EMAIL PROTECTED] |
---
