R help - Jan 2009 - Partial function application in R

Hello,

in a desperate desire of using partial function application in R I fried out
the following piece of code:

bind <- function( f, ... ) {
  args <- list(...)
  function(...) f( ..., unlist(args) )
}

Its purpose, if not clear, is to return a function with part of its
arguments bound to specific values, so that I can for example create and use
functions like this:
 q1 <- bind( quantile, 0.25 )
 lapply( some_list, q1 )

It's been a lot of work and unfortunately is not perfect. My bind applies
arguments only using positional rule. What I dream of is a function bind2
that would apply keyword arguments, like:
 plot_lines <- bind2( plot, type="l" )
which would return
 function(...) plot( type="l", ... )

How to do this in R?

Regards,
nosek
-- 
View this message in context:
http://www.nabble.com/Partial-function-application-in-R-tp21487269p21487269.html
Sent from the R help mailing list archive at Nabble.com.

How is function() not the correct approach?

 > plot_lines <- function(x, ...) plot(x,  type="l", ...)
 >
 > plot_lines(1:10, xlim = c(1,5))

 > plot_lines(1:10, 11:20, xlim = c(1,5))

Still seems to get the unnamed optional y argument to the plotting  
machinery.

-- 
David Winsemius

On Jan 15, 2009, at 4:25 PM, nosek wrote:
>
> Hello,
>
> in a desperate desire of using partial function application in R I  
> fried out
> the following piece of code:
>
> bind <- function( f, ... ) {
>  args <- list(...)
>  function(...) f( ..., unlist(args) )
> }
>
> Its purpose, if not clear, is to return a function with part of its
> arguments bound to specific values, so that I can for example create  
> and use
> functions like this:
> q1 <- bind( quantile, 0.25 )
> lapply( some_list, q1 )
>
> It's been a lot of work and unfortunately is not perfect. My bind  
> applies
> arguments only using positional rule. What I dream of is a function  
> bind2
> that would apply keyword arguments, like:
> plot_lines <- bind2( plot, type="l" )
> which would return
> function(...) plot( type="l", ... )
>
> How to do this in R?
>
> Regards,
> nosek
> -- 
> View this message in context:
http://www.nabble.com/Partial-function-application-in-R-tp21487269p21487269.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.

Have a look at the setDefaults package.  It will set the default
arguments of a function to whatever you specify so that
if you omit them then those are the values you get for them.

On Thu, Jan 15, 2009 at 4:25 PM, nosek <nospamek at interia.pl>
wrote:
>
> Hello,
>
> in a desperate desire of using partial function application in R I fried
out
> the following piece of code:
>
> bind <- function( f, ... ) {
>  args <- list(...)
>  function(...) f( ..., unlist(args) )
> }
>
> Its purpose, if not clear, is to return a function with part of its
> arguments bound to specific values, so that I can for example create and
use
> functions like this:
>  q1 <- bind( quantile, 0.25 )
>  lapply( some_list, q1 )
>
> It's been a lot of work and unfortunately is not perfect. My bind
applies
> arguments only using positional rule. What I dream of is a function bind2
> that would apply keyword arguments, like:
>  plot_lines <- bind2( plot, type="l" )
> which would return
>  function(...) plot( type="l", ... )
>
> How to do this in R?
>
> Regards,
> nosek
> --
> View this message in context:
http://www.nabble.com/Partial-function-application-in-R-tp21487269p21487269.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>