'functional' languages derive from LISP and the lamda-calculus. These are standard topics in CS computer language courses. You can look them up in Wikipedia, or Google for other sources.
-- Bert Gunter Genentech Non-Clinical Statistics South San Francisco, CA "The business of the statistician is to catalyze the scientific learning process." - George E. P. Box > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Patrick Burns > Sent: Tuesday, October 18, 2005 2:40 PM > To: ronggui > Cc: [email protected] > Subject: Re: [R] The meaning of functional language > > ronggui wrote: > > >It's often heard that the S language is a functional > language.But What's the exact meaning of this termology in > the context of S language? > > > > > > Here's the idea. If you have: > > x <- 1:10 > f <- function(y) { x <- sin(y / 2); x + y} > f(-3:3) > > then the 'x' inside 'f' does not wipe out your top-level 'x' > when 'f' is called. > > Operationally it means that objects are only changed via > the assignment operator. (This is not strictly true, but other > vehicles, such as '<<-', are generally considered bad style.) > > The reason for wanting this behavior is so that you don't need > to worry about objects getting invisibly changed while you > are analyzing some data, or whatever it is that you are doing. > That is, the language was designed to be human efficient, while > sacrificing some machine efficiency. > > Patrick Burns > [EMAIL PROTECTED] > +44 (0)20 8525 0696 > http://www.burns-stat.com > (home of S Poetry and "A Guide for the Unwilling S User") > > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
