[R] Variable alias

[Gabor Grothendieck]

If you only have to use y once then you can use delayedAssign. This
will assign a promise and the promise will not be evaluated until its
used:

> x
Error: object 'x' not found
> y
Error: object 'y' not found
> x <- y
> x <- 1
> delayedAssign("y", x)
> x <- 2
> y
[1] 2

If that's not good enough you can use makeActiveBinding:

> x <- 1
> makeActiveBinding("y", function() x, .GlobalEnv)
> y
[1] 1
> x <- 2
> y
[1] 2



On Sat, Aug 1, 2009 at 10:55 AM, Daniel Haase<dh at haase-zm.de> wrote:
> Hi Everyone,
>
> is there the possibility in R to assign a variable to be an alias of another
> one?
> Example:
>
> x <- 17
> # assign y to be an alias of x
> y # returns 17
> x <- 4
> y # returns 4
>
> Daniel
>
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