[R] Partial function application in R

[nosek]

Well, 

it looks like it's a perfectly correct approach to bind functions writing
their wrappers by hand.
But I don't want to write them by hand every time I need them.
Being lambda expression, function() is most general, but there must be some
kind of shorter way for such a common task as partial application.


David Winsemius wrote:
> 
> 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:
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>> Sent from the R help mailing list archive at Nabble.com.
>>
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> 
> ______________________________________________
> 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.
> 
> 

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