> I've been playing around with this for a while. One flaw I found - it
> doesn't handle nested Curries very well (the naive implementation in
> roxygen/functional does).
That's easily fixed:
Curry <- function(FUN, ...) {
args <- match.call(expand.dots = FALSE)$...
args$... <- as.name("...")
env <- parent.frame()
if (is.name(FUN)) {
fname <- FUN
} else if (is.character(FUN)) {
fname <- as.name(FUN)
} else if (is.function(FUN)){
fname <- FUN
# env$FUN <- FUN
} else {
stop("FUN not function or name of function")
}
curry_call <- as.call(c(list(fname), args))
f <- eval(call("function", as.pairlist(alist(... = )), curry_call))
environment(f) <- env
f
}
Curry(Curry(foo,3),4)
> e.g.:
>
> foo=function(x,y,z) x+y+z
> Curry(Curry("foo",3),4)(3)
> # 10
>
> Curry(Curry(foo,3),4)(3)
> # hangs
>
> foo4=function(a,b,c,d)
> Curry(Curry(Curry("foo4",3),4),1)(3)
> # hangs
>
> I was also curious if there was some trick to force a function eval when the
> list of arguments got exhausted (for example, a triple Curry on foo above
> would leave no arguments so would trigger eval into 10).
I don't think that would be a good idea - there's a big difference
between a function with no arguments and the result of calling that
function.
Hadley
--
Assistant Professor / Dobelman Family Junior Chair
Department of Statistics / Rice University
http://had.co.nz/
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