dsimcha wrote:
Bringing this analogy back to language design, if you make a language very highly configurable and don't provide good defaults, the barrier to entry will just be too high. If people have to understand a whole bunch of intricacies of the macro system to do anything more complex than "Hello, world", the language will be confined to a highly devoted niche. On the other hand, if you do provide strong conventions and sane defaults, people will probably avoid violating them because doing so would make their code no longer portable from programmer to programmer, and would probably break a whole bunch of library code, etc. that relies on the convention. In other words, they would feel like they were creating a whole new language, and for all practical purposes they would be. Thus, the purpose of this customizability would be defeated.
The symptom is visible: even with good defaults and all, such languages invariably come with the advice "don't use our best feature". That's terrible. It's a bad anguage design to put in power that can do more harm than good, to the extent that you openly unrecommend usage of the feature. Like you have a car with a very powerful engine but not a clutch to match (there are many, Subaru Impreza comes to mind). Then you have this awesome power on paper, but invariably the mechanic tells you: don't seal the pedal to the metal if you want to have a car.
I therefore much prefer D's templates which I use and also recommend to non-advanced users, plus the occasional string mixin that is a seldom-used feature instrumental to only a minority of idioms.
Andrei
