Composing Functions

In this post we implement the technique of Composing Functions

The idea of composing functions is based on the concatenation of operations

Consider the next code:

            int var1 = 100;
            int var2 = var1 * 1024;
            int var3 = var2 + 2048;

We could create functions to perform this and our code would be the next:

            int var1 = 100;
            int var2 = CalcVar2(var1);
            int var3 = CalcVar3(var2);


        int CalcVar2(int a)
        {
            return a * 1024;
        }

        int CalcVar3(int b)
        {
            return b + 2048;
        }

This then would be improved with Composition, which automates this step

        public static Func<TSource, TEndResult> Compose<TSource, TIntermediateResult, TEndResult>(
            this Func<TSource, TIntermediateResult> func1,
            Func<TIntermediateResult, TEndResult> func2)
        {
            return sourceParam => func2(func1(sourceParam));
        }

            var autoCalcVar1 = extensions.Compose(CalcVar2, CalcVar3);

            int result = autoCalcVar1(var1);

            Console.WriteLine(result);