On Sun, 15 Dec 2002, Craig Dickson wrote: > Date: Sun, 15 Dec 2002 09:16:43 -0800 > From: Craig Dickson <[EMAIL PROTECTED]> > To: Debian Users <[EMAIL PROTECTED]> > Subject: Re: OT: functional languages (was: Politics of Java) > > Colin Watson wrote: > > > You can pass function pointers around in C happily enough. I appreciate > > it's less theoretically elegant than having functions as first-class > > citizens, and that it doesn't allow as much compile-time checking, but > > does it really limit you? > > Yes, it does. C function pointers are just pointers to code; there is no > associated environment, no lexical scoping of variables, etc. This is > critical to the concept of a functional language (and the lack of > lexical scoping is one of the major reasons why traditional Lisp cannot > be considered an FPL).
Craig and others Having "undesirable" featuers such as maintaining state or having dynamic scoping, does not make a language not be functional. The paradigm in scheme and common lisp (both of which have static scoping by the way) is functional. A program in these languages is a collection of nested functions, so these are functional languages. When scheme added lexical scoping, it made that functional language much more useful. When Common Lisp added lexical (static) scoping, Common Lisp was much improved. Unfortunately they added some ketchup to the caviar by introducing the state maintaining looping, sequencing, assignment, and binding of functions and data to identifiers to Scheme. I believe these and I/O are the only imperative features of scheme, and (less certain) believe they are the only imperative features of lisp. David Teague -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
