From: "Wolfgang Nádasi-Donner" <ed.odanow@...>
Date: 2007-11-11T19:39:02+09:00
Subject: What does "Encoding.compatible?" do?

Hi!

While writing Ruby 1.9 informational parts for the german Ruby wiki I saw (ruby 
1.9.0 (2007-11-07 patchlevel 0) [i386-mingw32]) the method 
"Encoding.compatible?", which required two parameters. My first guess was, that 
it takes two encodings and returns "true" if they are compatible, but this is 
not the case.

The tests end up with results I don't understand:

Encoding.compatible?(Encoding.find("ascii-8bit"), Encoding.find("ascii")) => 
<Encoding:ASCII-8BIT>

Encoding.compatible?(Encoding.find("Shift_JIS"), Encoding.find("EUC-JP")) => nil

Encoding.compatible?(Encoding.find("Shift_JIS"), Encoding.find("ASCII-8BIT")) => 
<Encoding:Shift_JIS>

Encoding.compatible?(Encoding.find("Shift_JIS"), Encoding.find("ISO-8859-1")) => nil

Encoding.compatible?(Encoding.find("Shift_JIS"), Encoding.find("EUC-JP")) => nil

Encoding.compatible?(Encoding.find("ISO-8859-1"), Encoding.find("ISO-2022-JP")) 
=> nil

Encoding.compatible?(Encoding.find("ISO-8859-1"), Encoding.find("UTF-8")) => nil

What is the interpretation for these results?

Wolfgang N��dasi-Donner