Class: Karel::World

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

Overview

The world in which Karel operates.

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#height ⇒ Object (readonly)

Returns the value of attribute height.



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# File 'lib/karel/world.rb', line 7

def height
  @height
end

#karel ⇒ Object

Returns the value of attribute karel.



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# File 'lib/karel/world.rb', line 5

def karel
  @karel
end

#width ⇒ Object (readonly)

Returns the value of attribute width.



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# File 'lib/karel/world.rb', line 6

def width
  @width
end

Instance Method Details

#[](row, column) ⇒ Object

Provides access to the square at the given row/column

Returns a Square instance, on which you can call handy methods like beeper? and wall?



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# File 'lib/karel/world.rb', line 75

def [](row,column)
  @world[row][column]
end

#add_beeper(row, column) ⇒ Object

Adds a beeper tot he world at the given row/column

raises a SquareOccupied exception if there is a beeper or wall at those coordinates.



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# File 'lib/karel/world.rb', line 48

def add_beeper(row,column)
  self[row,column].put_beeper
end

#clear?(row, column) ⇒ Boolean

True if the square could be moved into by Karel

Returns:

  • (Boolean) 


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# File 'lib/karel/world.rb', line 64

def clear?(row,column)
  if in_bounds?(row,column)
    !self[row,column].wall?
  else
    false
  end
end

#create_from_string(definition, karel) ⇒ Object

Creates the world from a string that is a multi-line representation of the world. This isn’t the constructor because our DSL requires uppercase and we don’t want warnings by creating the world twice (once when declaring it as a constant in the Karel module and once inside the module method WORLD).

Raises:



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# File 'lib/karel/world.rb', line 13

def create_from_string(definition,karel)
  @karel = nil
  @karel_instance = karel
  @karel_instance.reset
  @world = []
  @width = 0
  row = 0
  column = 0
  rows = definition.split(/\n/)
  @height = rows.size
  rows.each do |row_data|
    @width = row_data.length if row_data.length > @width
    row_data.split(//).each do |square|
      @karel = [row,column] if square == 'K'
      @world[row] ||= []
      @world[row][column] = square_for(square)
      column += 1
    end
    column = 0
    row += 1
  end
  raise InvalidWorld,"There is no Karel in this World" unless @karel
  fill_in_empty_spaces
end

#remove_beeper(row, column) ⇒ Object

Removes a beeper from the world at the given row/column

raises a NoBeeper exception if there is no beeper at those coordinates.



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# File 'lib/karel/world.rb', line 41

def remove_beeper(row,column)
  self[row,column].pick_beeper
end

#to_s ⇒ Object

Returns the string representation, which looks like the the string used to construct this



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# File 'lib/karel/world.rb', line 81

def to_s
  string = "+"
  @width.times { string += '-' }
  string += "+\n"
  @height.times do |row|
    string += "|"
    @width.times do |column|
      kr,kc = karel
      if (kr == row) && (kc == column)
        string += @karel_instance.to_s
      else
        string += self[row,column].to_s
      end
    end
    string += "|\n"
  end
  string += "+"
  @width.times { string += '-' }
  string += "+\n"
  string
end