From: Joel VanderWerf <vjoel@...>
Date: 2002-12-18T17:04:47+09:00
Subject: Regex#=== with non-string argument


I'm surprised:

x = 1

case x
when 5;       puts "5"
when 42;      puts "42"
when /abc/;   puts "matches /abc/"
when "xyz";   puts "xyz"
end

This is a TypeError. Is there any good reason why?

I think it would make sense for Regex#=== (if not Regex#=~) to return 
false for non-Strings. Otherwise, this kind of case statement has to be 
broken into an 'if..else..end' and two 'case...end' statements.

Anyway this workaround is no good for me because, instead of a case 
statement, I have a list of given objects which respond to :===. I guess 
I could test for Regex, but that's not very elegant. Also, I can't just 
rescue TypeError, because I can't be sure that a given (user-supplied) 
object uses TypeError in this way (and maybe the TypeError is a 
programming error inside the user's #=== implementation).

The same goes for Range#=== .