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Showing posts from October, 2010

Invoking methods with Out and Ref !!!

Straight to code.....int SomeMethod(string arg1, string arg2, ref DayOfWeek arg3) { // Wildest implementation! }The above method had to be executed on its dispatcher thread. So let unravel a bit of the wildest implementation above.int SomeMethod(string arg1, string arg2, ref DayOfWeek arg3) { if (Disptacher.CheckAccess()) { var funcDelegate = (Func<string, string, DayOfWeek, int>)SomeMthod; return Dispatcher.Invoke(funcDelegate, arg1, arg2, ref arg3); } // Wilder implementation!! }Before you say anything, yes, the compiler spat the following errors:-Error 1 No overload for 'SomeMethod' matches delegate 'System.Func<string,string,DayOfWeek,int> Error 2 The best overloaded method match for 'System.Windows.Threading.Dispatcher.Invoke(System.Delegate, params object[])' has some invalid arguments Error 3 Argument '4': cannot convert from 'ref System.DayO…

Thinking Currying !!!

Currying is a mathematical concept based on lambda calculus. It is a technique of operating on a function (taking multiple arguments) by splitting and capable of chaining into a series of single argument functions. It is very similar to what a human would attempt to do on paper. For example, if you have to add numbers 1 through 10, what would you do? Class II mathematics....zero in hand, one in the mind, add 0 and 1, so 1 in the mind, then 2 in the hand, ...up to 10. So we compute the addition with one argument at a time. In the programming world, it is realized by transforming a n-arguments function into a (n-1) arguments function, which takes the remaining one argument. This transformation when applied recursively on each of the single argument functions is the chaining of single argument functions that I discussed earlier. Needless to say, currying is a gift of the functional programming world. In simple words, functional programming is about building functions from other functi…