Introduce an abstracted structure about the encoding of Reline

The command prompt on Windows always uses Unicode to take input and print
output but most Reline implementation depends on Encoding.default_external.
This commit introduces an abstracted structure about the encoding of Reline.

lib/reline.rb

@@ -38,8 +38,10 @@ module Reline
     attr_accessor :ambiguous_width
     attr_accessor :last_incremental_search
     attr_reader :output
+    attr_reader :encoding
 
-    def initialize
+    def initialize(encoding)
+      @encoding = encoding
       self.output = STDOUT
       yield self
       @completion_quote_character = nil
@@ -49,36 +51,36 @@ module Reline
       if val.nil?
         @completion_append_character = nil
       elsif val.size == 1
-        @completion_append_character = val.encode(Encoding::default_external)
+        @completion_append_character = val.encode(@encoding)
       elsif val.size > 1
-        @completion_append_character = val[0].encode(Encoding::default_external)
+        @completion_append_character = val[0].encode(@encoding)
       else
         @completion_append_character = nil
       end
     end
 
     def basic_word_break_characters=(v)
-      @basic_word_break_characters = v.encode(Encoding::default_external)
+      @basic_word_break_characters = v.encode(@encoding)
     end
 
     def completer_word_break_characters=(v)
-      @completer_word_break_characters = v.encode(Encoding::default_external)
+      @completer_word_break_characters = v.encode(@encoding)
     end
 
     def basic_quote_characters=(v)
-      @basic_quote_characters = v.encode(Encoding::default_external)
+      @basic_quote_characters = v.encode(@encoding)
     end
 
     def completer_quote_characters=(v)
-      @completer_quote_characters = v.encode(Encoding::default_external)
+      @completer_quote_characters = v.encode(@encoding)
     end
 
     def filename_quote_characters=(v)
-      @filename_quote_characters = v.encode(Encoding::default_external)
+      @filename_quote_characters = v.encode(@encoding)
     end
 
     def special_prefixes=(v)
-      @special_prefixes = v.encode(Encoding::default_external)
+      @special_prefixes = v.encode(@encoding)
     end
 
     def completion_case_fold=(v)
@@ -201,7 +203,7 @@ module Reline
       otio = Reline::IOGate.prep
 
       may_req_ambiguous_char_width
-      line_editor.reset(prompt)
+      line_editor.reset(prompt, encoding: @encoding)
       if multiline
         line_editor.multiline_on
         if block_given?
@@ -387,11 +389,15 @@ module Reline
   def_instance_delegators self, :readmultiline
   private :readmultiline
 
+  def self.encoding_system_needs
+    self.core.encoding
+  end
+
   def self.core
-    @core ||= Core.new { |core|
+    @core ||= Core.new(Reline::IOGate.encoding) { |core|
       core.config = Reline::Config.new
       core.key_stroke = Reline::KeyStroke.new(core.config)
-      core.line_editor = Reline::LineEditor.new(core.config)
+      core.line_editor = Reline::LineEditor.new(core.config, Reline::IOGate.encoding)
 
       core.basic_word_break_characters = " \t\n`><=;|&{("
       core.completer_word_break_characters = " \t\n`><=;|&{("
@@ -405,8 +411,6 @@ module Reline
   def self.line_editor
     core.line_editor
   end
-
-  HISTORY = History.new(core.config)
 end
 
 if RbConfig::CONFIG['host_os'] =~ /mswin|msys|mingw|cygwin|bccwin|wince|emc/
@@ -422,4 +426,5 @@ else
   require 'reline/ansi'
   Reline::IOGate = Reline::ANSI
 end
+Reline::HISTORY = Reline::History.new(Reline.core.config)
 require 'reline/general_io'

lib/reline/ansi.rb

@@ -1,6 +1,10 @@
 require 'io/console'
 
 class Reline::ANSI
+  def self.encoding
+    Encoding.default_external
+  end
+
   RAW_KEYSTROKE_CONFIG = {
     [27, 91, 65] => :ed_prev_history,     # ↑
     [27, 91, 66] => :ed_next_history,     # ↓

lib/reline/general_io.rb

@@ -1,6 +1,10 @@
 require 'timeout'
 
 class Reline::GeneralIO
+  def self.encoding
+    Encoding.default_external
+  end
+
   RAW_KEYSTROKE_CONFIG = {}
 
   @@buf = []

lib/reline/history.rb

@@ -19,7 +19,7 @@ class Reline::History < Array
 
   def []=(index, val)
     index = check_index(index)
-    super(index, String.new(val, encoding: Encoding::default_external))
+    super(index, String.new(val, encoding: Reline.encoding_system_needs))
   end
 
   def concat(*val)
@@ -39,12 +39,12 @@ class Reline::History < Array
         val.shift(diff)
       end
     end
-    super(*(val.map{ |v| String.new(v, encoding: Encoding::default_external) }))
+    super(*(val.map{ |v| String.new(v, encoding: Reline.encoding_system_needs) }))
   end
 
   def <<(val)
     shift if size + 1 > @config.history_size
-    super(String.new(val, encoding: Encoding::default_external))
+    super(String.new(val, encoding: Reline.encoding_system_needs))
   end
 
   private def check_index(index)

lib/reline/line_editor.rb

@@ -57,10 +57,10 @@ class Reline::LineEditor
   NON_PRINTING_END = "\2"
   WIDTH_SCANNER = /\G(?:#{NON_PRINTING_START}|#{NON_PRINTING_END}|#{CSI_REGEXP}|#{OSC_REGEXP}|\X)/
 
-  def initialize(config)
+  def initialize(config, encoding)
     @config = config
     @completion_append_character = ''
-    reset_variables
+    reset_variables(encoding: encoding)
   end
 
   private def check_multiline_prompt(buffer, prompt)
@@ -85,10 +85,10 @@ class Reline::LineEditor
     end
   end
 
-  def reset(prompt = '', encoding = Encoding.default_external)
+  def reset(prompt = '', encoding:)
     @rest_height = (Reline::IOGate.get_screen_size.first - 1) - Reline::IOGate.cursor_pos.y
     @screen_size = Reline::IOGate.get_screen_size
-    reset_variables(prompt, encoding)
+    reset_variables(prompt, encoding: encoding)
     @old_trap = Signal.trap('SIGINT') {
       @old_trap.call if @old_trap.respond_to?(:call) # can also be string, ex: "DEFAULT"
       raise Interrupt
@@ -139,7 +139,7 @@ class Reline::LineEditor
     @eof
   end
 
-  def reset_variables(prompt = '', encoding = Encoding.default_external)
+  def reset_variables(prompt = '', encoding:)
     @prompt = prompt
     @mark_pointer = nil
     @encoding = encoding

lib/reline/windows.rb

@@ -1,6 +1,10 @@
 require 'fiddle/import'
 
 class Reline::Windows
+  def self.encoding
+    Encoding::UTF_8
+  end
+
   RAW_KEYSTROKE_CONFIG = {
     [224, 72] => :ed_prev_history, # ↑
     [224, 80] => :ed_next_history, # ↓
@@ -99,7 +103,7 @@ class Reline::Windows
         return @@input_buf.shift
       end
       begin
-        bytes = ret.chr(Encoding::UTF_8).encode(Encoding.default_external).bytes
+        bytes = ret.chr(Encoding::UTF_8).bytes
         @@input_buf.push(*bytes)
       rescue Encoding::UndefinedConversionError
         @@input_buf << ret

test/reline/test_key_actor_emacs.rb

@@ -8,8 +8,8 @@ class Reline::KeyActor::Emacs::Test < Reline::TestCase
     Reline::HISTORY.instance_variable_set(:@config, @config)
     Reline::HISTORY.clear
     @encoding = (RELINE_TEST_ENCODING rescue Encoding.default_external)
-    @line_editor = Reline::LineEditor.new(@config)
-    @line_editor.reset(@prompt, @encoding)
+    @line_editor = Reline::LineEditor.new(@config, @encoding)
+    @line_editor.reset(@prompt, encoding: @encoding)
   end
 
   def test_ed_insert_one

test/reline/test_key_actor_vi.rb

@@ -9,8 +9,8 @@ class Reline::KeyActor::ViInsert::Test < Reline::TestCase
       set editing-mode vi
     LINES
     @encoding = (RELINE_TEST_ENCODING rescue Encoding.default_external)
-    @line_editor = Reline::LineEditor.new(@config)
-    @line_editor.reset(@prompt, @encoding)
+    @line_editor = Reline::LineEditor.new(@config, @encoding)
+    @line_editor.reset(@prompt, encoding: @encoding)
   end
 
   def test_vi_command_mode

test/reline/test_macro.rb

@@ -3,7 +3,8 @@ require_relative 'helper'
 class Reline::MacroTest < Reline::TestCase
   def setup
     @config = Reline::Config.new
-    @line_editor = Reline::LineEditor.new(@config)
+    @encoding = (RELINE_TEST_ENCODING rescue Encoding.default_external)
+    @line_editor = Reline::LineEditor.new(@config, @encoding)
     @line_editor.instance_variable_set(:@screen_size, [24, 80])
     @output = @line_editor.output = File.open(IO::NULL, "w")
   end

test/reline/test_string_processing.rb

@@ -7,8 +7,8 @@ class Reline::LineEditor::StringProcessingTest < Reline::TestCase
     @config = Reline::Config.new
     Reline::HISTORY.instance_variable_set(:@config, @config)
     @encoding = (RELINE_TEST_ENCODING rescue Encoding.default_external)
-    @line_editor = Reline::LineEditor.new(@config)
-    @line_editor.reset(@prompt, @encoding)
+    @line_editor = Reline::LineEditor.new(@config, @encoding)
+    @line_editor.reset(@prompt, encoding: @encoding)
   end
 
   def test_calculate_width