From: John Halderman <jhalderman@...>
Date: 2005-07-23T04:30:00+09:00
Subject: Possible bug with StringScanner class

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I'm not sure if this is a bug or intentional behavior, so I thought I would=
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post it here to see what the community thought of what was happening. If yo=
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set up a StringScanner object to perform iterative matching on a string the=
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behavior of \A and ^ seem to always match. It seems to me that \A should=20
only match if it is the first match performed, and ^ should only match if=
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bol? returns true, which should be after a \n or if it is the first match=
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performed. Here is some code I ran in irb to illustrate the problem:

require 'strscan'
sc =3D StringScanner.new("the white elephant eats grass")
sc.scan(/the\s+/)
sc.bol?
sc.scan(/^white\s+/)
sc.scan(/\Aelephant\s+/)

this code produced the following result.
irb(main):001:0> require 'strscan'
=3D> true
irb(main):002:0> sc =3D StringScanner.new("the white elephant eats grass")
=3D> #<StringScanner 0/29 @ "the w...">
irb(main):003:0> sc.scan(/the\s+/)
=3D> "the "
irb(main):004:0> sc.bol?
=3D> false
irb(main):005:0> sc.scan(/^white\s+/)
=3D> "white "
irb(main):006:0> sc.scan(/\Aelephant\s+/)
=3D> "elephant "

Any thoughts and or advice on this matter are greatly appreciated.

-John Halderman

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