Lambda calculus

lambda_calculus.rb

def cons(x,y)
  lambda {|m|
    m.call(x, 
           y,
           lambda {|n| x = n},
           lambda {|n| y = n}
          )
  }
end

def car(x)
  x.call(
    lambda {|a, d, sa, sd| a}
  )
end

def cdr(x)
  x.call(
    lambda {|a, d, sa, sd| d}
  )
end

def set_car!(x, y)
  x.call(
    lambda {|a, d, sa, sd| sa.call(y)}
  )
end

def set_cdr!(x, y)
  x.call(
    lambda {|a, d, sa, sd| sd.call(y)}
  )
end