From: Warren Brown <warrenbrown@...>
Date: 2005-11-23T15:41:32+09:00
Subject: [BUG] string range membership

All,

    I ran across some code that was trying to validate that an integer
was in a given range, however the integer and the range were Strings.
The problem boils down to this:

>ruby -e "p ('1'..'10').member?('2')"
false

    Given that...

>ruby -v -e "('1'..'10').each {|s| p s}"
ruby 1.8.2 (2004-12-25) [i386-mswin32]
"1"
"2"
"3"
"4"
"5"
"6"
"7"
"8"
"9"
"10"

    ...it seems like ('1'..'10').member?('2') should return true.  The
problem lies in range.c, in the range_each_func() method.  This method
starts with the first value, then calls succ() to get the next value,
breaking out of the loop when the value is no longer less than or equal
to the ending value (or strictly less than the ending value on an
exclusive range).  Unfortunately, for the given string range this
happens immediately, since '2' > '10'.

    I suppose that it could be argued that this is not a bug, but that
would be a difficult argument to win.  Also, I need to make sure that
this is still a bug in the latest version of Ruby.  Unfortunately, I'm
too sleepy to investigate further or create a patch for this tonight,
but I'll try to work on it some more tomorrow night (assuming nobody
else fixes it first).

    - Warren Brown