From: Michael Davis <mdavis@...>
Date: 2002-03-11T04:39:39+09:00
Subject: Issue with trapping errors in instance_eval

I need to be able to trap error during a call to instance_eval.  Here is 
a code snip-it that closely resembles what I am trying to do.  This 
errors but never hits the rescue clause.  Any idea how to trap an error 
inside a call to instance_eval?

a = [1,2]
begin
   a.instance_eval('puts a2.inspect')
rescue
   puts 'error'
end


I was expecting to see:

     error

however, this little program outputs the following:

Exception `NameError' at (eval):1 - undefined local variable or method 
`a2' for [1, 2]:Array
Exception `NameError' at ../test.rb:3 - (eval):1:in `instance_eval': 
undefined local variable or method `a2' for [1, 2]:Array
../test.rb:3:in `instance_eval': (eval):1:in `instance_eval': undefined 
local variable or method `a2' for [1, 2]:Array (NameError)
         from ../test.rb:3:in `instance_eval'
         from ../test.rb:3


I am running Ruby 1.6.5 on Windows 2000 with the latest version of cygwin.

-- 
Thanks, Michael Davis
Database Architect and Senior Software Engineer, Seva Inc.
Email: mdavis@sevainc.com