From: Kent Dahl <kentda@...>
Date: 2003-07-24T07:49:28+09:00
Subject: Re: "regex literal in condition"

Daniel Carrera wrote:
> # My code
> while gets.
>     break if (/\<\!-{19} ending left_colum -{11}\>/)
> end
> 
> # Output:
> warning: regex literal in condition
> 
> What is a "regex literal"?  How is that different from any other regex?
> I just want to read a text file and skip all the lines until I arrive at
> the one matching the expression above.

A literal is something written directly into the source.
  "hi" = String literal
  /hi/ = Regexp literal
  Regexp.new( "hi" ) = String literal passed to Regexp constructor

Ruby does some freaky stuff in some cases, such as when you have a
literal in an if, the exact usage you are looking for: an implicit
match. Notice how if you do

re = /\<\!-{19} ending left_colum -{11}\>/
while gets
    break if re 
end   

then "gets" is only called once because any object instance turns true
in a boolean condition. My money is on Matz wanting to deprecate the
implicit matching in the future and this is your very early and literal
warning.

HTH

-- 
(\[ Kent Dahl ]/)_    _~_    _____[ http://www.pvv.org/~kentda/ ]_____/~
 ))\_student_/((  \__d L b__/ (pre-) Master of Science in Technology  )
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