Class: AI::LineEditor

Inherits:
Object
  • Object
show all
Defined in:
lib/line_editor.rb

Overview

── Mini line editor with history + Tab completion (with cycling) ────

Constant Summary collapse

SIGNALS = 
{
  "\ej"     => :sess_next,
  "\ek"     => :sess_prev,
  "\el"     => :redraw,  "\eL" => :redraw,
  "\e[3;7~" => :del_session, "\e\e[3;5~" => :del_session,
  "\e[3;5~" => :del_session, "\e\e[3^"   => :del_session,
  "\e[3^"   => :del_session, "\e[3;8~"   => :del_session
}.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ LineEditor

Returns a new instance of LineEditor.



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# File 'lib/line_editor.rb', line 15

def initialize; @history = []; @completer = nil; end

Instance Attribute Details

#completer ⇒ Object

Returns the value of attribute completer.



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# File 'lib/line_editor.rb', line 4

def completer
  @completer
end

#history ⇒ Object

Returns the value of attribute history.



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# File 'lib/line_editor.rb', line 4

def history
  @history
end

Instance Method Details

#readline(prompt) ⇒ Object 



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# File 'lib/line_editor.rb', line 17

def readline(prompt)
  @prompt = prompt; @buf = +""; @cur = 0
  @hpos = @history.length; @stash = nil
  @prev_rows = 0; @prev_cur_row = 0
  @cycle = nil
  render
  $stdin.raw do |io|
    loop do
      k = read_key(io) or next
      if (sig = SIGNALS[k]) then return signal(sig) end
      @cycle = nil unless k == "\t"
      case k
      when "\r", "\n" then return submit
      when "\t"       then handle_tab
      when "\x03" then end_render; print "\r\n"; raise Interrupt
      when "\e[3~"
        @buf.slice!(@cur); render if @cur < @buf.length
      when "\x02", "\e[D" then move(-1)
      when "\x06", "\e[C" then move(+1)
      when "\x01", "\e[H", "\eOH", "\e[1~" then @cur = 0; render
      when "\x05", "\e[F", "\eOF", "\e[4~" then @cur = @buf.length; render
      when "\eb"  then @cur = word_back; render
      when "\ef"  then @cur = word_fwd;  render
      when "\x10", "\e[A" then history_step(-1)
      when "\x0e", "\e[B" then history_step(+1)
      when "\x7f", "\b", "\x08"
        (@buf.slice!(@cur - 1); @cur -= 1; render) if @cur > 0
      when "\x04"
        if @buf.empty? then end_render; print "\r\n"; return nil
        elsif @cur < @buf.length then @buf.slice!(@cur); render
        end
      when "\x0b" then @buf.slice!(@cur..);  render
      when "\x15" then @buf.slice!(0...@cur); @cur = 0; render
      when "\x17"
        j = word_back; @buf.slice!(j...@cur); @cur = j; render
      when "\ed"
        j = word_fwd;  @buf.slice!(@cur...j); render
      when "\eu" then case_word(:upcase);   render
      when "\eU" then case_word(:downcase); render
      when "\x14" then transpose; render
      when "\x0c" then print "\e[H\e[2J"; @prev_rows = 0; @prev_cur_row = 0; render
      when "\e"   then nil
      else insert(k) if printable?(k)
      end
    end
  end
end