class IRB::Canvas
def draw
def draw @data.each {|row| row.fill(0) } yield @data.map {|row| row.map {|n| " ',;"[n] }.join }.join("\n") end
def draw @data.each {|row| row.fill(0) } yield @data.map {|row| row.map {|n| " ',;"[n] }.join }.join("\n") end