design question

Erich Neuwirth asks:

let me ask you as possibly very silly question.

what  would you think of a shorthand notation for anonymous fuctions in
arguments?

let me illustrate this in how mathematica does it.

mathematica has a function notation like R

Map[Function[x, x^2], {1, 2, 3}]

this can be abbreviated as
Map[#^2 &, {1, 2, 3}]

The Maple notation is more understandable to most people:

	map(x -> x^2, {1, 2, 3})

but of course "->" is already taken in S/R as the right pointing
assignment operator (although maybe I'm the only one who even knows
about it, let alone uses it...)

& indicates a function expression,
and # is the (one) anonymous argument.
functions with more that one arguments
(whch are positional) can be written as
#1  #2
and so on

Either swiped from TeX or both have swiped the idea from a common
source.  It has the look of a macro language, which can be misleading.

here is an example
Outer[#1^2 + #2^2 &, {1, 2}, {3, 4}]

Cryptic for most users, I'd say, and very macro-like.

in some cases, this notation is quite convenient.
and since r is lexically scoped, it also should not be too dangerous.
what do our architects think about introducing this kind of notation
in r?

It has to have very low priority, possibly negative.  If syntactic
revisions were ever seriously contemplated, I would strongly favour
trying to bring in some of the S4 changes, but even there I would
regard the semantic extensions as much more urgent than the purely
syntactic ones.  Consistency with S-PLUS is not the final arbiter of
everthing but it does really matter.

Bill Venables,      Statistician,     CMIS Environmetrics Project
CSIRO Marine Labs, PO Box 120, Cleveland, Qld,  AUSTRALIA.   4163
Tel: +61 7 3826 7251           Email: Bill.Venables@cmis.csiro.au    
Fax: +61 7 3826 7304      http://www.cmis.csiro.au/bill.venables/



-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-devel mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-devel-request@stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._