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How i can construct regexp, which will always matches nothing?

For example:

"xxxxxxx".match /my_special_regexp/
=> should be ALWAYS nil
--
Posted via http://www.ruby-forum.com/.

Joao Silva wrote:
> How i can construct regexp, which will always matches nothing?
>
> For example:
>
> "xxxxxxx".match /my_special_regexp/
> => should be ALWAYS nil

How about:

re = /$a^/

--
Posted via http://www.ruby-forum.com/.

Why do you want to have a such regex ?

Anyway, it seems that /^$a/ will never match with any string.

"a".match /^$a/
=> nil
"".match /^$a/
=> nil
"a ".match /^$a/
=> nil
--
Posted via http://www.ruby-forum.com/.

7stud -- wrote:
> Joao Silva wrote:
>> How i can construct regexp, which will always matches nothing?
>>
>> For example:
>>
>> "xxxxxxx".match /my_special_regexp/
>> => should be ALWAYS nil
>
> How about:
>
> re = /$a^/

I guess that could be made even simpler:

re = /a^/

--
Posted via http://www.ruby-forum.com/.

Joao Silva wrote:
> How i can construct regexp, which will always matches nothing?
>
> For example:
>
> "xxxxxxx".match /my_special_regexp/
> => should be ALWAYS nil
not sure, but something that should always be nil .... what about the constant 'nil'

7stud -- wrote:
> 7stud -- wrote:
>> Joao Silva wrote:
>>> How i can construct regexp, which will always matches nothing?
>>>
>>> For example:
>>>
>>> "xxxxxxx".match /my_special_regexp/
>>> => should be ALWAYS nil
>>
>> How about:
>>
>> re = /$a^/
>
> I guess that could be made even simpler:
>
> re = /a^/

..and probably more efficient:

re = /a\A/
--
Posted via http://www.ruby-forum.com/.

Joao Silva wrote:
> How i can construct regexp, which will always matches nothing?
>
> For example:
>
> "xxxxxxx".match /my_special_regexp/
> => should be ALWAYS nil

Just out of curiosity: Why do you use a method call, when you expect a constant?