irb > require 'rsruby'
irb > ENV['R_HOME'] ||= '/usr/lib/R'
irb > $R = RSRuby.instance
irb > $R.assign('test.x', { :a => 1, :b => "abc", :c => [8,9] } )
RException: Error in (function (x, value, pos = -1, envir = as.environment(pos), inherits = FALSE, :
unused arguments (a = 1, b = "abc", c = 8:9)
This happens because rsruby treats a trailing Hash as a collection of keyword arguments to the R assign() function. All that metaprogramming magic ain't free, y'know?
The solution is to wrap the Hash argument into an actual Hash storing keyword arguments to the R function.
A quick look at the R help file for assign() shows that it has the following signature:
assign(x, value, pos = -1, envir = as.environment(pos),
inherits = FALSE, immediate = TRUE)
This means that the Hash containing the R List data will have to be passed as the value argument to the assign() call.
$R.assign('test.x', { :value => { :a => 1, :b => "abc", :c => [8,9] } } )
ArgumentError: Unsupported object ':a' passed to R.
Of course, R cannot handle Symbols unless they are the names of function keyword arguments. This is easy to fix.
irb >$R.assign('test.x', { :value => { 'a' => 1, 'b' => "abc", 'c' => [8,9] } } )
=> {"a"=>1, "b"=>"abc", "c"=>[8, 9]}
irb > $R.eval_R("print(test.x)")
$a
[1] 1
$b
[1] "abc"
$c
[1] 8 9
=> {"a"=>1, "b"=>"abc", "c"=>[8, 9]}
All's well that ends well!