Neelakantan Krishnaswami wrote: > In article <[EMAIL PROTECTED]>, Pascal Costanza wrote: >> Torben Ægidius Mogensen wrote: >> >>> On a similar note, is a statically typed langauge more or less >>> expressive than a dynamically typed language? Some would say less, as >>> you can write programs in a dynamically typed language that you can't >>> compile in a statically typed language (without a lot of encoding), >>> whereas the converse isn't true. >> It's important to get the levels right here: A programming language >> with a rich static type system is more expressive at the type level, >> but less expressive at the base level (for some useful notion of >> expressiveness ;). > > This doesn't seem obviously the case to me. If you have static > information about your program, the compiler can use this information > to automate a lot of grunt work away. > > Haskell's system of typeclasses work this way. If you tell the > compiler how to print integers, and how to print lists, then when you > call a print function on a list of list of integers, then the compiler > will automatically figure out the right print function using your base > definitions. This yields an increase in Felleisen-expressiveness over > a dynamically typed language, because you would need to globally > restructure your program to achieve a similar effect. > > More dramatic are the "polytypic" programming languages, which let you > automate even more by letting you write generic map, fold, and print > functions which work at every type.
Yes, but these decisions are taken at compile time, without running the program. Pascal -- 3rd European Lisp Workshop July 3 - Nantes, France - co-located with ECOOP 2006 http://lisp-ecoop06.bknr.net/ -- http://mail.python.org/mailman/listinfo/python-list
