Improved Function Information with <TAB> Key
On Thu, Oct 8, 2009 at 5:33 AM, Lee Kelvin <lee.s.kelvin at gmail.com> wrote:
Thanks for the responses, Im not familiar with the development of readline 6, is it possible to test this functionality now, or will this be included in a future standard release of R?
I don't think it's possible to test it now (but I can't say for sure as I don't have readline 6 installed and haven't read the documentation carefully). In theory, some future release should include a check for readline>=6 and disable sorting, but I'm not sure when or if that will happen in practice.
Also, it was suggested that Emacs and the ESS package may be of use.? Im not overly familiar with emacs, but I will give it a go.
As far as I can tell, Emacs' completion system also sorts, and I don't see a way to inhibit that. ESS does show you the results of args() when you type an open paren after a function name, which should be useful for you. -Deepayan
Thanks, ??? Lee Kelvin 2009/10/8 Deepayan Sarkar <deepayan.sarkar at gmail.com>
On Wed, Oct 7, 2009 at 5:56 AM, Lee Kelvin <lee.s.kelvin at gmail.com> wrote:
Hello, Pressing the <TAB> key when typing a function into an R terminal does not produce the expected output. ?Currently, R will order all of the available function inputs into alphabetical order and present them as options, whereas it should display the inputs in the order they appear in the function. For example:
test = function(b,a,c){
print(b) a*c }
test( ? <TAB><TAB>
a= ?b= ?c= where <TAB> indicates pressing the Tab key. It's easy to see that if the function were designed to accept 'b' as a string, and 'a' and 'c' as numerics that this function would fail if the user made the assumption that the <TAB> output is in the correct order, and input 'a' as a string. This is a simple example, however I have several functions that I use often and each has many possible inputs. ?It would be useful to not have to remember the order the inputs are in for each function, or have to use args(function) beforehand. ?It is also on occasion useful not to have to explicitly name each input in your function. Im using Ubuntu Linux 9.04 and a standard install of R 2.9.2 (unfortunately not the polished R.app available on Macs - which coincidentally do display function inputs in the correct order). I welcome any thoughts, disagreements or tips any of you may have,
The sorting is a feature of the readline library that is used as the backend (there is no sorting on the Windows GUI). Apparently readline 6 allows you to inhibit sorting, so that might turn out to be useful. -Deepayan
-- Lee Kelvin lee.s.kelvin at gmail.com 07765431721