At 2001-04-09 10:29, Dylan Thurston wrote:
I hadn't thought about doing rational arithmetic with GCDs. Might be
nice.
Herewith my attempt. I can't test it though, it runs afoul of one of the
many bugs in Hugs' type-extension handling, and I haven't been able to
run GHC on my MacOS X box.
--
At 2001-04-19 01:19, Ashley Yakeley wrote:
Herewith my attempt.
Sorry, that should have gone to the Haskell Cafe list.
--
Ashley Yakeley, Seattle WA
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You shouldn't need rational exponents to take square roots as long as no
*ground* type requires them. If polymorphism over units were primitive,
then
we'd have something like
sqrt :: Real (u.u) - Real u
for a fixed numeric type Real that's parameterized over its units. (BTW,
it's
not possible
Andrew Kennedy [EMAIL PROTECTED] wrote:
You shouldn't need rational exponents to take square roots as long as no
*ground* type requires them.
Rational exponents for ground types are not strictly required
but sometimes very convenient. I'm not a physicist, but a web
search for "sqrt(hz)" turns
Dear All,
| 1) What is a fundep?
Fundeps are "functional dependencies", which have long been used to
specify constraints on the tables used in relational databases. In
the current context, people are using "fundeps" to refer to the way
that this idea has been adapted to work with multiple
On Mon, Apr 09, 2001 at 09:36:45AM -0700, anatoli wrote:
It seems that fundeps are powerful enough to do
compile-time dimensional analysis in Haskell. That
is, one can devise types that represent dimensions of
quantities, such as (meter / second) or
(kilogram * meter / second^2),
and have
At 2001-04-09 09:36, anatoli wrote:
It seems that fundeps are powerful enough to do
compile-time dimensional analysis in Haskell.
I'm very impressed and slightly frightened. And there was me complaining
that since you can't parameterise types in Haskell by integer (or other
values) the way
At 2001-04-09 09:36, anatoli wrote:
4) Allow several unit systems (such as SI and Imperial)
to coexist.
That's easy. Just hide the 'Dimensioned' constructor so no-one can see
what system you're using.
--
type One = Succ Zero
type Mass rep = Dimensioned One Zero Zero rep
type Length
1) What is a fundep?
2) This is a very interesting topic, and rather complex. It
has come up (dimensions, units, -- not Haskell implementations
of them) in some recent work on STEP (ISO 10303). I'm only
now trying to come up to some speed on Haskell, and only now
trying to recall what I used
