On Feb 24, 2010, at 10:15 AM, Heinrich Apfelmus wrote:
Namely, let's assume we are already given a magic type
constructor |-
(so magic that it's not even legal Haskell syntax) with the property
that
A |- B
somehow denotes an expression of type B with free variables of
type A
.
Günther Schmidt wrote:
I've been thinking a lot lately about heterogeneous and extensible data
structures for which HList certainly offers a solution.
While HList is implemented through type-level programming I wonder if I
can achieve similar results through value-level programming alone.
Alexander Solla wrote:
So, the type (View view) -- ignoring class instances -- is basically
isomorphic to this (slightly simpler) type:
data View = EmptyView | TextView String | ConcatView View View |
NestViews View View View | ...
instance Monoid View where ...
Now, consider the
On Feb 20, 2010, at 10:25 AM, Heinrich Apfelmus wrote:
But isn't the line
renderXHtml (ConcatView l r) = fold $ renderXHtml (ConcatViews l r)
a type error? I'm assuming
Data.Foldable.fold :: (Foldable m, Monoid t) = m t - t
being applied to the result type of renderXHtml which is
Hi Alexander,
sry for being a bit thick, but how would this code be used?
I'm unable to figure out the application yet. Could you give some
examples how you use it?
Günther
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sry for being a bit thick, but how would this code be used?
I'm unable to figure out the application yet. Could you give some
examples how you use it?
Günther
So, the type (View view) -- ignoring class instances -- is basically
isomorphic to this (slightly simpler) type:
data View
Hi Alex,
this looks very very interesting, gimme some time to figure it. I hope
you'll take questions later ...
Günther
Am 16.02.10 22:34, schrieb Alexander Solla:
On Feb 16, 2010, at 12:48 PM, Alexander Solla wrote:
(Accumulator String)s are (Accumulator value)s for any value. So you
