Class: RGnuchess::Gnuchess

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

Overview

Gnuchess represents an interface to the program ‘gnuchess’

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Gnuchess

Returns a new instance of Gnuchess.



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# File 'lib/rgnuchess.rb', line 143

def initialize
  @gc=IO.popen("gnuchess -me","r+")
  4.times{@gc.gets} #eat opening lines
end

Instance Method Details

#board ⇒ Object

retrieve the current Board



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# File 'lib/rgnuchess.rb', line 162

def board
  command("show board")
  @gc.gets_until(/ /)
  board_lines = @gc.gets_until(/^$/,1)[0...-1]
  board = Board.parse board_lines
end

#load(file) ⇒ Object

load a file that gnuchess can load (e.g. a .epd file)



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# File 'lib/rgnuchess.rb', line 156

def load(file)
  command "load #{file}"
  count=0
  @gc.gets_until(/^$/, 3)
end

#make_move(move) ⇒ Object

make a move



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# File 'lib/rgnuchess.rb', line 191

def make_move(move)
  command "#{move}"
  #eat until prompt
  count=0
  if @gc.gets=~/^Illegal move/
    raise InvalidMoveException, "illegal move"
  end
  @gc.gets_until(/^$/)
end

#moves ⇒ Object

get an array of all valid moves



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# File 'lib/rgnuchess.rb', line 169

def moves
  command "show moves"
  lines = @gc.gets_until(/No\. of moves/)
  #parse moves
  mvs=lines[0...-1].join("\n").scan(/[a-zA-Z][^\s]*/)
  mvs.map! { |str| Move.parse( str ) }
  #this should never happen, but we check anyway
  count=lines.last.scan(/\d+/)[0].to_i
  fail "wrong number of moves!" unless mvs.size==count
  #filter invalid moves
  mvs = mvs.select do |mv|
    begin
      make_move mv
      undo
      true
    rescue InvalidMoveException
      false
    end
  end
  return mvs
end

#test ⇒ Object 



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# File 'lib/rgnuchess.rb', line 206

def test
  load "board.epd"
  mv = moves.select{|mv| mv.checkmate?}.first
  make_move mv
  undo
  puts "test complete"
end

#undo ⇒ Object

undo a move



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# File 'lib/rgnuchess.rb', line 201

def undo
  command "undo"
  count=0
  @gc.gets_until(/^$/,2)
end