gistfile1.txt

% $R16B03_1_hipe/bin/erlc utf8_with_magic_comment.erl
% $R16B03_1_hipe/bin/erl -noshell -s utf8_with_magic_comment start -s init stop
 ===== format by 's'
[bytes]: あ
 ===== format by 'ts'
[codepoint]: \x{3042}
[bytes]: あ
[string_literal]: \x{3042}
 ===== format by 'ts' with io:setopts([{encoding, utf8}])
[codepoint]: あ
[bytes]: ã
[string_literal]: あ

utf8_with_magic_comment.erl

%% -*- coding: utf-8 -*-
-module(utf8_with_magic_comment).
-compile(export_all).

start() ->
    io:format(" ===== format by 's'~n"),
    [catch io:format("[~s]: ~s~n",
                     [HowToCreate, hiragana_A(HowToCreate)]) ||
        HowToCreate <- [codepoint, bytes, string_literal]],
    io:format(" ===== format by 'ts'~n"),
    [catch io:format("[~s]: ~ts~n",
                     [HowToCreate, hiragana_A(HowToCreate)]) ||
        HowToCreate <- [codepoint, bytes, string_literal]],
    
    io:format(" ===== format by 'ts' with io:setopts([{encoding, utf8}])~n"),
    io:setopts([{encoding, utf8}]),
    [catch io:format("[~s]: ~ts~n",
                     [HowToCreate, hiragana_A(HowToCreate)]) ||
        HowToCreate <- [codepoint, bytes, string_literal]].

hiragana_A(codepoint) ->
    [12354];
hiragana_A(bytes) ->
    [227,129,130];
hiragana_A(string_literal) ->
    "あ".