From: Tammo Freese <tammo.freese@...>
Date: 2001-03-14T01:27:28+09:00
Subject: [ruby-talk:12572] bug in String#hex and String#oct


Hello,

by scanning through the reference in the pickaxe book and
trying out things with IRB, I have found a strange behaviour.

The method String#hex is described:

"Treats leading characters [...] as a string of hexadecimal
digits (with an optional sign and an optional 0x) and returns
the corresponding number. Zero is returned on error."

So I expected zero when calling this method on a string that
begins with two signs. However, here are the results:

$ ruby -ve 'puts "++1".hex.to_s'
ruby 1.6.3 (2001-03-07) [i686-cygwin]
1

$ ruby -ve 'puts "+-1".hex.to_s'
ruby 1.6.3 (2001-03-07) [i686-cygwin]
4294967295

$ ruby -ve 'puts "-+1".hex.to_s'
ruby 1.6.3 (2001-03-07) [i686-cygwin]
-1

$ ruby -ve 'puts "--1".hex.to_s'
ruby 1.6.3 (2001-03-07) [i686-cygwin]
-4294967295

With three signs, zero is returned. String#oct has 
the same behaviour.


-
Tammo Freese
freese@acm.org