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Showing posts from June, 2009

Mobile Code in C# via Finally Tagless Interpreters

Awhile back I described an idea to transparently execute code server-side or client-side given the same program. I've finally gotten around to implementing this using my encoding for type constructor polymorphism in C#.

Here is an example you can run from the original paper showcasing exponentiation which can execute transparently either server-side or client-side. The server-side code is intentionally limited to bases less than 100 and exponents less than 20.

Here is some simplified code that defines an exponentiation function:
void Build<B, R>(B _)
where B : ISymantics<B>, new()
{
var e = _.Lambda<int, Func<int, int>>(
x => _.Fix<int, int>(self => _.Lambda<int, int>(n =>
_.If(_.Lte(n, _.Int(0)), () => _.Int(1),
() => _.Mul(x, _.Apply(self, _.Add(n, _.Int(-1))))))));
}
The parameter "_" is the tagless interpeter and it's type is ISymantics<B>,…