On 4/27/05, Ali - <[EMAIL PROTECTED]> wrote: 
> 
> Assume we have a function like:
> 
> foo <- function(x, y)
> 
> how is it possible to define a binary indexing operator, denoted by $, so
> that
> 
> x$y
> 
> functions the same as
> 
> foo(x, y)

  Here is an example. Note that $ does not evaluate y so you have
to do it yourself:

x <- structure(3, class = "myclass")
y <- 5
foo <- function(x,y) x+y
"$.myclass" <- function(x, i) { i <- eval.parent(parse(text=i)); foo(x, i) }
x$y # structure(8, class = "myclass")

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