Regular expression mismatch?

ruby-talk
1

Hello,

Why does the following:

s = "aaa aaa\n\n\nbbb bbb"
puts(s =~ /^\s+$/)

produce: 8 (instead of nil) ?

(If I put in only 2 newlines, it's fine).

This is in several 1.8.2 rpms (caliban, fc3).

Cheers,

Han Holl

2

Hello,

Why does the following:

s = "aaa aaa\n\n\nbbb bbb"
puts(s =~ /^\s+$/)

produce: 8 (instead of nil) ?

^ means the beginning a line (right after \n)
$ means the end a line (right before \n)
\s+ manes one or more whitespace characters (the \n in the middle)

Does that clarify the match?

(If I put in only 2 newlines, it's fine).

You can't satisfy all three conditions with only two \n characters.

Hope that helps.

James Edward Gray II

···

On Apr 6, 2005, at 9:44 AM, Han Holl wrote:

3

Han Holl wrote:

Why does the following:

s = "aaa aaa\n\n\nbbb bbb"
puts(s =~ /^\s+$/)

produce: 8 (instead of nil) ?

Maybe you would rather use \A and \Z instead of ^ and $:

puts(s =~ /\A\s+\Z/) => nil

···

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Glenn Parker | glenn.parker-AT-comcast.net | <http://www.tetrafoil.com/&gt;