Walter Bright Wrote: > language_fan wrote: > > This seems more like an advertisement of D than practical new information > > for compiler construction. Nesting functions is the basic feature of > > functional languages. Moreover even procedural Algol based languages such > > as Pascal have always supported them, too. > > But not C, C++, Java, etc., so quite a lot of programmers have little > experience with them, and even less understanding. > > > This information is also > > taught in basic university level compiler courses. > > I bet only a tiny fraction of programmers have taken university compiler > classes. (Also, they were not covered in compiler classes I took.) > Consider also that the Java JVM doesn't support static links, and last I > heard the .NET IL didn't, either. > > > > Now that I checked what wikipedia had to say to the matter, it also > > seemed to mention D. Apparently 'c-like syntax' plus 'advanced feature > > <foo>' always equals 'innovation'. > > > Nested functions aren't innovative; they just are apparently lacking in > many other popular languages, and seem to confuse a lot of people. If > you google it, you'll find there's a lot of programmer confusion about > them. Hence an article as to how they work is in order. > > In part 2, I'll cover innovative things D does with nested functions.
I agree with Walter here. While D is not the first place I see closures and nested functions, it is the first language I come across that blends delegates, closures and nested functions in a simple, elegant and intuitive manner. PHP for one does not support closures at all, and delegates are done using the ugly array(object => 'method') syntax. JavaScript works like C#; you have to assign a closure to a delegate value to get a nested function. C/C++ also don't support closures, and delegates must be manually handled (function ptr + void* param) with very little support from many existing APIs (win32 is especially bad for that as it only uses static callbacks). Its no surprise that I was literally drooling when I first read about how D does it, I had just spent a few weeks doing jQuery in JavaScript for a client back then and fell in love with closures, D had it all with better syntax :) In D you can even send a function pointer to a delegate value!
