Don't be to disappointed. One can always kinda fake lazy evaluation using mutable cells. But not that elegantly. In the example given above, all being used is iterators as streams... this can also be expressed using lazy lists, true. But one big difference between e.g. lazy lists and iterators is, that lazy values are (operationally) replaced by their result wheres values generated from iterators and streams are not.
For example one can use Iterators and chain them together in Java, to achieve more or less the same space and runtime-efficiency found by Stream-fusion in haskell (the Java JIT can abstract loads away, once the iterators are build together). But If you need to access the iterator's values more then once, you have to either force the full iterator into a list or rerun/reevaluate the iterator every time you need a value. Lazy lists are nice, but haskell's laziness is not about lazy lists only. For example lazy evaluation also matters when creating "elegant" Embedded DSLs... have you ever tried to build a more complex EDSL without laziness and macros? On 5 Okt., 16:52, C K Kashyap <ckkash...@gmail.com> wrote: > > Yes. It would slightly easier in, say, C# or C++. > > I think 'D' achieves its implementation of the 'lazy' keyword using a > > similar approach. > > But I did not understand why you are disappointed ? > > The disappointment was not on a serious note ... the thing is, I > constantly run into discussions > about "why fp" with my colleagues - in a few of such discussions, I > had mentioned that Haskell is the > only well known language with lazy evaluation (IIRC, I read it > somewhere or heard it in one of the videos) > > And I had built up this impression that laziness distinguished Haskell > by a huge margin ... but it seems that is not the case. > Hence the disappointment. > > -- > Regards, > Kashyap > _______________________________________________ > Haskell-Cafe mailing list > haskell-c...@haskell.orghttp://www.haskell.org/mailman/listinfo/haskell-cafe _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe