[R] Functional pattern-matching in R

[Gabor Grothendieck]

Using the list function defined here:
http://tolstoy.newcastle.edu.au/R/help/04/06/1430.html

list[m, n] <- as.list(dim(iris))

mylist <- as.list(1:5)
list[Head, Tail] <- list(mylist[[1]], mylist[-1])


On Wed, Oct 29, 2008 at 4:39 PM, Alexy Khrabrov <deliverable at gmail.com> wrote:
> I found there's a very good functional set of operations in R, such as apply
> family, Hadley Wickham's lovely plyr, etc.  There's even a Reduce (a.k.a.
> fold).  Now I wonder how can we do pattern-matching?
>
> E.g., now I split dimensions like this:
>
>        m <- dim(V)[1] # R
>        n <- dim(V)[2]  # still R
>
> While even Matlab allows for
>
> [m,n] = size(V) % MATLAB!
>
> Ideally I'd be able to say,
>
> <<x,y>> <- dim(V)
>
> -- where <<.,.>> is some magic needed.
>
> Similarly, to break lists, we'd need, in a MLish notation,
>
> match L with
> | head::tail => ...
> | () => ;
>
> What can be done in R now to simulate it, and/or how Rish is it to add
> something like that?
>
> Cheers,
> Alexy
>
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