From: Eric Wong <normalperson@...>
Date: 2014-11-16T12:08:51+00:00
Subject: [ruby-core:66318] Re: [ruby-trunk - Bug #10518] [Open] String "delete" method does not remove some characters from input string

sergio.gallelli@gmail.com wrote:
> irb(main):001:0> str = 'A-B'
> => "A-B"
> irb(main):002:0> str.delete ' -#'
> => "A-B"

' -#' is interpreted as: range of characters from ' ' (space) to '#'.
See String#count documentation

I suppose it is weird and surprising behavior, but I doubt it can change
for compatibility.  I would normally use String#tr if I wanted a range.