Comments on: Clojure Golf episode 1

By: Saptarshi

Saptarshi — Wed, 24 Mar 2010 16:34:27 +0000

Hello, I apologize for the repeated posts, this the last one for sure. A bit more space efficient:

filter.collecting <- function(predicate, collector,...){

z <- mapply(function(...) if(do.call(predicate,list(...))) do.call(collector,list(...)) ,...,SIMPLIFY=TRUE);

Filter(function(r) !is.null(r), z);

}

filter.collecting('<','+', c(1,7,3,9),c(5,5,5,5));

By: Saptarshi

Saptarshi — Wed, 24 Mar 2010 16:06:55 +0000

Oops, the newlines disappeared, here it is again filter.collecting <- function(predicate, collector, ...){

w <- which(mapply(predicate, ...))

newl <- lapply(list(...),function(r) r[w])

newl$FUN <- collector

do.call("mapply",newl)

}

usage ::

filter.collecting("<","+", c(1,7,3,9),c(5,5,5,5))

By: Saptarshi

Saptarshi — Wed, 24 Mar 2010 16:05:51 +0000

Rather later in the day, but for the R language:

filter.collecting <- function(predicate, collector, ...){ w <- which(mapply(predicate, ...)) newl <- lapply(list(...),function(r) r[w]) newl$FUN <- collector do.call("mapply",newl) }

usage ::

filter.collecting("<","+", c(1,7,3,9),c(5,5,5,5))

By: fogus

fogus — Mon, 24 Aug 2009 17:40:40 +0000

@Ronen,

Thanks for the snippet(s). I tend to like your second solution the best for the same reason that I like Grand's -- it tells the story of its functionality. The next step would be to lose your heads. ;) I agree with all of your comments and it goes to show that although Clojure can quite easily be translated directly from Scheme, that approach is not likely to yield idiomatic results.

-m

By: Eric Normand

Eric Normand — Mon, 17 Aug 2009 15:23:58 +0000

It’s a pretty simple function.

http://gist.github.com/169171