currying.rb

# Create a lambda that adds its 2 params
adder = ->(x, y) { x + y }

# Curry it to pre-populate the first param with 2. This effectively turns
# add_two into ->(2, y) { 2 + y }
add_two = adder.curry[2]

# Call add_two with some other args
add_two.call(3)
# => 5
add_two.call(7)
# => 9