String#% strange arity errors
When the number of arguments do not match the number of % parameters, the String#% method has some odd behavior.
When too many, it seems to work fine, ignoring the extra arguments.
"%s" % [1,2] #=> "1"
$DEBUG = true,
"%s" % [1,2] #=> ArgumentError: too many arguments for format string
That doesn't seem right. Is it an error or isn't it?
For too few arguments it is always an error:
"%s" %  #=> ArgumentError: too few arguments
Personally, I think it should use '' for missing arguments. That would make it more flexible in practice.
I consider the first $DEBUG issue a bug, and the later a feature. But I'll just call it a feature altogether to make things easier.