Feature #5898
closedraise and Exception#initialize
Description
Calling #raise
with a message
parameter passes the argument on the Exception class' initialize method. But it does not support any additional arguments if the initialize method has been defined otherwise. Nor is the last optional argument, caller
, passed to the initializer. All of which makes for a rather confusing mishmash of an interface between #raise
and Exception#initialize
.
Ideally I would think whatever arguments are passed to #raise
would likewise be passed on to Exception#initialize
, e.g.
class MyError < Exception
def initialize(a,b)
super("#{a} and #{b}")
end
end
raise MyError, 'foo', 'bar'
Alas, because caller
can be passed to #raise
this causes an error, as it thinks bar
ought to be the caller array. So unless others see a way around it that I do not, this idealized scenario simply is not possible.
So I propose a second best approach. Notice that if caller
is passed to #raise
it is not being passed on to the #initialize
method unlike the message
argument. Instead #set_backtrace
is being used to set the caller. I propose that the message
argument be handled in the same way, and a new method #set_message(msg)
be added to the Exception
class to handle it.
This would then allow the initializer of subclasses to be freed up to be defined in other ways, should a specialized exception be able to make good use of a variant interface Which, btw, is the exact circumstance I presently find myself in for one of my projects. Consequently I had no choice by to define the #initialize method to take an initial blank argument that will almost always be set to +nil+.
Updated by nobu (Nobuyoshi Nakada) over 12 years ago
- Status changed from Open to Rejected