encodings/source_encoding_and_new.rb

tests/_examples/encodings/source_encoding_and_new.rb in the metorex repository.

# encoding: us-ascii
# `__ENCODING__` names the encoding of the source it is written in, which is
# settled where it is written rather than where the code around it is run.
p(__ENCODING__)
p(eval("__ENCODING__".dup.force_encoding("BINARY")))
p(eval("# encoding: utf-8\n__ENCODING__"))

# An encoding is an instance of Encoding rather than a class of its own.
p(Encoding::UTF_8.is_a?(Encoding))
p(Encoding::UTF_8.is_a?(Class))

# `String.new` takes the characters it was given in the encoding the
# `encoding:` keyword names, empty and reading as bytes with no argument at
# all, and refuses anything that does not read as a String.
p(String.new.encoding)
p(String.new("abc", encoding: "EUC-JP").encoding)
p(String.new("abc", capacity: 100))
begin
  String.new(5)
rescue TypeError => refused
  p(refused.class)
end

Output:

#<Encoding:US-ASCII>
#<Encoding:BINARY (ASCII-8BIT)>
#<Encoding:UTF-8>
true
false
#<Encoding:BINARY (ASCII-8BIT)>
#<Encoding:EUC-JP>
"abc"
TypeError