Class: AI::LineEditor

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

Overview

── Mini line editor with history + Tab completion ───────────────────

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
PASTE_STYLE = 
"\e[48;5;18;38;5;231m"
BPASTE_ON = 
"\e[?2004h"
BPASTE_OFF = 
"\e[?2004l"

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 19

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 21

def readline(prompt)
  @prompt = prompt.to_s; @buf = +""; @cur = 0
  @hpos = @history.length; @stash = nil
  @prev_rows = 1; @prev_cur_row = 0
  @cycle = nil
  @pastes = []
  print BPASTE_ON
  render
  begin
    $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 "\e[200~" then collect_paste(io)
        when "\r", "\n" then insert("\n")
        when "\e\r", "\e\n" then return submit
        when "\t" then handle_tab
        when "\x03" then end_render; print "\r\n"; raise Interrupt
        when "\e[3~" then forward_delete
        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" then backspace
        when "\x04"
          if @buf.empty? then end_render; print "\r\n"; return nil else forward_delete end
        when "\x0b" then del_range(@cur, @buf.length); render
        when "\x15" then del_range(0, @cur); render
        when "\x17" then j = word_back; del_range(j, @cur); render
        when "\ed" then j = word_fwd; del_range(@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
  ensure
    print BPASTE_OFF
  end
end