On Wednesday 21 August 2002 11:12 am, Slava Potsepnia wrote:
> Hi All!
>
> I would like to know if it's possible to negate regexps in
> case-when-then-else-end. I.g.
>
> line ="I need to know"
> case line
>        when <not>? <!>? /^I need .*/
>        puts "right"
> end
>
> Best regards,
> Slava Potsepnia

I may be all wrong, but I thought case was equivalent to:
if line === something
	do_something
elseif line === something_else
	do_something_else
else
	do_default
end

If this is so, that "===" is implied, then the "when" cannot contain just the 
regex.  This is klunky but works:

def nomatch(str, regex)
	if str !~ regex
		str
	else
		nil
	end
end
line = "I nyeed to know"
regex = %r{^I need.*}
case line
when regex
	puts "a match"
when nomatch(line, regex)
	puts "no match"
end