Recursive Calling

Description

Recall is used as a placeholder for the name of the function in which it is called. It allows the definition of recursive functions which still work after being renamed, see example below.

Usage

Recall(...)

Arguments

Note

Recall will not work correctly when passed as a function argument, e.g. to the apply family of functions.

See Also

do.call and call.

local for another way to write anonymous recursive functions.

Examples

## A trivial (but inefficient!) example:
fib <- function(n)
   if(n<=2) { if(n>=0) 1 else 0 } else Recall(n-1) + Recall(n-2)
fibonacci <- fib; rm(fib)
## renaming wouldn't work without Recall
fibonacci(10) # 55