Assign a complex regular expression string

Rails
1

Hi,

I have a complex regular expression:

[a-z0-9!#$%&’+/=?^_{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_{|}~-]+)@(?:a-z0-9?.)+(?:[A-Z]{2}|com|org|net|gov|biz|info|name|aero|biz|info|jobs|museum)\b

And I want to assign it to a Constant which I’ll use to reference it in
my code.

If I put it between “” it gets evaluated, which breaks because it is
full of “meaningful” characters.
If I put it between ‘’ it breaks because it contains ’

I was reluctant to fill the regexp with escape “/” characters as I am
sure I will break it.

Is there any other way to get this value assigned to a Constant ?

Thanks!

2

I was reluctant to fill the regexp with escape “/” characters as I am
sure I will break it.

That should work unless maybe there’s something odd in your expression?

In IRB if you try

MYCONST = /foo/
=> /foo/
“barfoo”.index(MYCONST)
=> 3

If you’re sure your expression is correct maybe you could explicitly
create a RegExp object?

i.e.
RegExp.new(“regexp” …

See here:
http://www.ruby-doc.org/core/classes/Regexp.html#M001219

Cheers
Luke

3

On 7 Oct 2007, at 09:38, John L. wrote:

it in
my code.

If I put it between “” it gets evaluated, which breaks because it is
full of “meaningful” characters.
If I put it between ‘’ it breaks because it contains ’
Don’t forget there are other ways to define strings, in particular,

%q

You can use any character after the q (eg %q{some string}), although
in general the point is to pick one which doesn’t occur much in the
string itself, so that you don’t have to escape it. %q{} is like ‘’
in that it doesn’t try and interpolate stuff, whereas %Q{} is like “”
in that it does. In your case %q seems to do the trick.
Fred

4

On 10/7/07, John L. [email protected] wrote:

If I put it between “” it gets evaluated, which breaks because it is
full of “meaningful” characters.
If I put it between ‘’ it breaks because it contains ’

I was reluctant to fill the regexp with escape “/” characters as I am
sure I will break it.

Is there any other way to get this value assigned to a Constant ?

Why not

MyConstant =
/[a-z0-9!#$%&'+/=?^_{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_{|}~-]+)@(?:a-z0-9?.)+(?:[A-Z]{2}|com|org|net|gov|biz|info|name|aero|biz|info|jobs|museum)\b/

–
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/

5

Ok thanks for the two suggestions. I never knew about %q.