Hi, this is my first post so apologies if I do anything wrong. I’m having trouble with inheritance and the ‘require’ keyword:
Issue:
I am making a command line chess program in Ruby, and I have a structure as such: (parent -> inherits from parent) Chess -> Piece -> Pawn, Knight, Rook, Bishop, King, Queen. Each class is in their own separate .rb file, all in the ./lib/ directory of my main chess directory.
If I require_relative chess in piece.rb, I get a Name Error: Uninitialized Constant: Piece whenever I try and run anything. Here are the files in question:
chess.rb
require_relative ‘piece’
require_relative ‘board’
require_relative ‘pawn’
require_relative ‘rook’
require_relative ‘knight’
require_relative ‘bishop’
require_relative ‘queen’
require_relative ‘king’
class Chess
attr_accessor :board
def initialize
end
def new_game
@board = Board.new
8.times do |i| # Add pawns to the board.
@board.board[1][i] = Pawn.new(1,i,"w")
@board.board[6][i] = Pawn.new(6,i,"b")
end
# Create white pieces
@board.board[0][0] = Rook.new(0,0,"w")
@board.board[0][1] = Knight.new(0,1,"w")
@board.board[0][2] = Bishop.new(0,2,"w")
@board.board[0][3] = Queen.new(0,3,"w")
@board.board[0][4] = King.new(0,4,"w")
@board.board[0][5] = Bishop.new(0,5,"w")
@board.board[0][6] = Knight.new(0,6,"w")
@board.board[0][7] = Rook.new(0,7,"w")
# Create black pieces
@board.board[7][0] = Rook.new(7,0,"b")
@board.board[7][1] = Knight.new(7,1,"b")
@board.board[7][2] = Bishop.new(7,2,"b")
@board.board[7][3] = Queen.new(7,3,"b")
@board.board[7][4] = King.new(7,4,"b")
@board.board[7][5] = Bishop.new(7,5,"b")
@board.board[7][6] = Knight.new(7,6,"b")
@board.board[7][7] = Rook.new(7,7,"b")
end
def get_valid_moves(moves) # Incomplete method
moves = moves.select{|move|}
end
end
piece.rb
require_relative ‘chess’
require_relative ‘pawn’
class Piece < Chess
attr_accessor :x,:y,:icon
def initialize(x,y,colour)
@x = x
@y = y
@colour = colour # Colour will be "w" or "b"
@icon
end
def valid_space?(move)
if move[0]> 7 || move[1] > 7 || move[0] < 0 || move[1] < 0
return false
end
true
end
end
pawn.rb (as this is where my console is saying the errors are)
require_relative ‘piece’
require_relative ‘chess’
class Pawn < Piece
def initialize(x,y,colour)
super
@colour == "b" ? (@icon = "♙") : (@icon = "♟")
@move_count = 0
end
def list_all_moves
moves = []
moves.push([@x+2,@y]) if move_count == 0
moves.push([@x+1,@y])
moves = moves.select{|move| valid_space?(move)}
# More stuff that will be in chess.rb
end
end
What I’ve tried
- Absolute paths to files
- Requiring and unrequiring everything
- Changing order of requires
Any help with this would be great, I’m completely stumped - it works fine until I require ‘chess’ in ‘piece.rb’ or I try to get Piece to inherit from Chess. (or Both).
Traceback (most recent call last):
6: from lib/chess.rb:1:in `<main>'
5: from lib/chess.rb:1:in `require_relative'
4: from /home/nat/Documents/odin/projects/chess/lib/piece.rb:1:in `<top (required)>'
3: from /home/nat/Documents/odin/projects/chess/lib/piece.rb:1:in `require_relative'
2: from /home/nat/Documents/odin/projects/chess/lib/chess.rb:3:in `<top (required)>'
1: from /home/nat/Documents/odin/projects/chess/lib/chess.rb:3:in `require_relative'
/home/nat/Documents/odin/projects/chess/lib/pawn.rb:4:in `<top (required)>': uninitialized constant Piece (NameError)