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Below a Compose function. If f and g are unary functions which return values, then Compose(f,g) returns a function which when called on x performs the equivalent to f(g(x)).
static Func<X, Z> Compose<Z, Y, X>(Func<Y, Z> f,Func<X, Y> g)
{ return x => f(g(x)); }
Here's a couple of simple Func values which can be composed:
Func<int, bool> is_zero = x => { return x == 0; };
Func<int, int> mod_by_2 = x => { return x % 2; };
E.g. this works:
Console.WriteLine(Compose(is_zero, mod_by_2)(4));
However, if I instead have these equivalent static methods:
static bool IsZero(int n) { return n == 0; }
static int ModBy2(int n) { return n % 2; }
the same example doesn't work with those. I.e. this produces a compile time error:
Console.WriteLine(Compose(IsZero, ModBy2)(4));
Explicitly passing types to Compose fixes the issue:
Console.WriteLine(Compose<bool, int, int>(IsZero, ModBy2)(4));
Is there anyway to write Compose such that it works on the static methods without the explicit types?
Is this a good approach to take to implementing Compose? Can anyone make improvements to this?