From: "naruse (Yui NARUSE)" <naruse@...>
Date: 2013-11-21T16:35:22+09:00
Subject: [ruby-core:58459] [ruby-trunk - Feature #9111] Encoding-free String	comparison


Issue #9111 has been updated by naruse (Yui NARUSE).


Hanmac (Hans Mackowiak) wrote:
> what about strings with the same encoding, but different content, but that is turned the same? 
> like "��" can be maked from "a" + "^" somehow, should they also treated as equal?

The standard practice is  NFD("��") == NFD("a" + "^").
To NFD, you can use some libraries.
see also http://bibwild.wordpress.com/2013/11/19/benchmarking-ruby-unicode-normalization-alternatives/
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Feature #9111: Encoding-free String comparison
https://bugs.ruby-lang.org/issues/9111#change-43054

Author: sawa (Tsuyoshi Sawada)
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 


=begin
Currently, strings with the same content but with different encodings count as different strings. This causes strange behaviour as below (noted in StackOverflow question http://stackoverflow.com/questions/19977788/strange-behavior-in-packed-ruby-strings#19978206):

    [128].pack("C")             # => "\x80"
    [128].pack("C") == "\x80"   # => false

Since `[128].pack("C")` has the encoding ASCII-8BIT and `"\x80"` (by default) has the encoding UTF-8, the two strings are not equal.

Also, comparison of strings with different encodings may end up with a messy, unintended result.

I suggest that the comparison `String#<=>` should not be based on the respective encoding of the strings, but all the strings should be internally converted to UTF-8 for the purpose of comparison.


=end


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