Original message from prad [EMAIL PROTECTED]: > On Monday 22 May 2006 17:54, you wrote: > ... > i was puzzled reading something on one of the wikipedia links provided: > "The opposite of lazy evaluation is eager evaluation, also known as strict > evaluation. Eager evaluation is the evaluation behavior used in most > programming languages." > http://en.wikipedia.org/wiki/Lazy_evaluation > > it would seem to me that lazy evaluation makes more sense than eager > evaluation since it is both more logical and economical. > > i do not know much about language interpretation or compilation processes, > but > how can it possibly be of any advantage to do 2 things when you can get away > doing just one? > > so why would 'most programming languages' NOT use it? there must be some > benefit eager evaluation offers despite what seems to be a lack of efficient > evaluation. > > is eager evaluation easier to design or implement perhaps?
Whether an application is compiled has no bearing on short-circuiting. This feature can be implemented in either environment. As for why all languages don't use this feature, I suspect it is for purity. An expression is specified in code, it should be executed. OTOH, short-circuiting is simply an efficiency optimization. As for whether it is easier to implement short-circuiting or not, IMO short-circuiting isn't that hard to do. It's really up to the language designer as to whether they see that short-circuiting is congruent with the goals of the language. For languages intending on emphasizing pedantic behavior prescribed in code, short-circuiting would probably not be implemented. For languages wanting to provide performance optimizations as part of the language, implementing short-circuiting makes sense. Jim
