Peter Dalgaard wrote: > Johannes Huesing wrote: >> Stavros Macrakis <[EMAIL PROTECTED]> [Wed, Dec 10, 2008 at >> 04:59:25AM CET]: >>> So I conclude that what is really meant by "R semantics are based on >>> Scheme >>> semantics" is "R has functions as first-class citizens and a correct >>> implementation of lexical scope, including upwards funarg". >>> >> >> One other thing reminiscient of Lisp is the infix notation (as in >> "+"(1, 3)), which the authors have sprinkled with enough syntactic >> sugar that the users >> needn't be bothered with. To the benefit of ubiquity, I'd think. >> > > That's prefix notation, infix is "1+3" (and postfix is "1,3,+" as in > old HP calculators). But you're right that R has Lisp-like parse trees > with a thin layer of syntactic sugar: > > Lisp writes function calls as (f x y) for f(x,y) and (+ 1 3) for 1+3. > In R we have > > > e <- quote(f(x,y)) > > e[[1]];e[[2]]; e[[3]] > f > x > y > > e <- quote(1+3) > > e[[1]];e[[2]]; e[[3]] > `+` > [1] 1 > [1] 3 >
the reminiscence is limited, though. the following won't do: `+`(1,2,3) and quote(1+2+3) is not a list of `+`, 1, 2, and 3. vQ ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
