ResultComparison<TResult>

Nov 10th, 2010 | Comments

At work recently, we had code looking a little something like this:

string val; int comp = Comparer<int>.Default.Compare (0, 1); if (comp > 0) val = "greater than"; else if (comp < 0) val = "less than"; else val = "equal";

When refactoring the code, I thought about the recent blog post about A Less Ugly Switch Statement and thought I might do something similar with IComparer (and IComparable, but I’ll leave that as an excercise for the reader). The envisioned invocation is:

string val = Comparer<int>.Default .ToComparison<int, string> (0, 1)) .GreaterThan (() => "greater than") .LessThan (() => "less than") .Equal (() => "equal") .Result;

I ended up with this implementation:

public static class Comparison { public static ResultComparison<TResult> ToComparison<TSource, TResult> (this IComparer<TSource> comparer, TSource, x, TSource y) { if (comparer == null) throw new ArgumentNullException ("comparer"); return new ResultComparison<TResult> (comparer.Compare (x, y)); } } public class ResultComparison<T> { T Result { get; private set; } int _comparison; public ResultComparison<T> Equal (Func<T> func) { if (_comparison == 0) Result = func (); return this; } public ResultComparison<T> LessThan (Func<T> func) { if (_comparison < 0) Result = func (); return this; } public ResultComparison<T> GreaterThan (Func<T> func) { if (_comparison > 0) Result = func (); return this; } public ResultComparison (int comparison) { _comparison = comparison; } }

Is this better? I’m not really sure. It is functionally equivalent. Is it more readable, or less?

10/6

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ResultComparison<TResult>

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