An example of then

then_example.rb

# https://benkoshy.github.io/2024/12/09/then-ruby-keyword.html

# this is a contrived example
# experiment with it in an IRB console.

# we want to:
# take a string
# add convert it to an int
# add 1 to that
# and then cube it
# returning the result

def operation_1(a)      
      a_int = (a.to_i)
      sum = a_int + 1
      cube = sum ** 3
      return cube
end

# is it pleasant to read?

puts "operation_1 is: #{operation_1("3")}"
# => operation_1 is: 64

# notice how the input of one function
# is an input into another?
# we can write the same thing like this:

def operation_2_dense(a)
      (a.to_i + 1) ** 3
end

puts "operation_2_dense is: #{operation_2_dense("3")}"
# => operation_1 is: 64

# but is it readable?

# you can also curry it like so:
def curry(a)
      a.then { |i| i.to_i }
       .then { |i| i + 1 }
       .then { |i| i ** 3 }      
end

puts "curry is #{curry("3")}"
# => curry is 64

def add_one(i)
      i + 1
end

def cube(i)
      i ** 3
end

def curry_2(a)
      a.then { |i| i.to_i }
       .then { |i| add_one(i) }
       .then { |i| cube(i) }      
end

puts "curry_2 is #{curry_2("3")}"
# => curry_2 is 64

# if you want something more readable.
# and if you like, you could put add_one and cube
# into a mixin. The implementation details are hidden
# and you can cleanly / elegantly express
# what you want.