I. What is tap?

tap is a method defined in the Object class in Ruby. It takes a block as an argument and yields the receiver object to that block. The block can then perform operations on the receiver object and return a value. The tap method itself returns the receiver object, allowing you to chain method calls together.

1. How tap works

Here’s an example of how tap works:

result = "hello".tap { |str| puts "Original string: #{str}" }
                  .upcase
                  .tap { |str| puts "Uppercase string: #{str}" }

# Output:
# Original string: hello
# Uppercase string: HELLO

puts result
# HELLO

In this example, the tap method yields the string "hello" to the first block, which prints the original string. The upcase method is then called on the string, and the tap method yields the uppercase string to the second block, which prints the uppercase string. The final result is the uppercase string "HELLO", which is stored in the result variable.

2. Use cases for tap

tap is commonly used in scenarios where you want to perform side effects on an object without affecting the method chain. For example, you can use tap to log intermediate values, debug code, or modify an object in place.

II. What is yield_self?

yield_self is a method defined in the Object class in Ruby. It takes a block as an argument and yields the receiver object to that block. The block can then transform the receiver object and return a new value. The yield_self method returns the value returned by the block, allowing you to chain method calls together.

1. How yield_self works

Here’s an example of how yield_self works:

result = "hello"
           .yield_self { |str| str.upcase }
           .yield_self { |str| str.reverse }

puts result
# OLLEH

In this example, the yield_self method yields the string "hello" to the first block, which transforms the string to uppercase. The resulting uppercase string is then yielded to the second block, which reverses the string. The final result is the reversed uppercase string "OLLEH", which is stored in the result variable.

2. Use cases for yield_self

yield_self is commonly used in scenarios where you want to transform data in a method chain. For example, you can use yield_self to apply a series of transformations to an object, or to extract a value from an object and transform it into a new value.

III. Key differences between tap and yield_self

1. Return value

  • tap: tap returns the receiver object after yielding it to the block. This allows you to chain method calls together and perform side effects on the receiver object.
  • yield_self: yield_self returns the value returned by the block. This allows you to transform the receiver object and chain method calls together.

2. Use cases

  • tap: Use tap when you want to perform side effects on an object without affecting the method chain.
  • yield_self: Use yield_self when you want to transform the receiver object and return a new value in the method chain.

3. Chaining

  • tap: tap is typically used to perform side effects on an object in the method chain. It does not transform the receiver object.
  • yield_self: yield_self is used to transform the receiver object and return a new value in the method chain. It allows you to apply a series of transformations to an object.

IV. Real-world scenarios

In real-world scenarios, tap and yield_self can be used to simplify code and make it more readable. For example, you can use tap to log intermediate values in a method chain, or yield_self to transform data in a functional programming style.

Here’s an example of how tap and yield_self can be used together:

result = "hello"
           .yield_self { |str| str.upcase }
           .tap { |str| puts "Uppercase string: #{str}" }
           .yield_self { |str| str.reverse }
           .tap { |str| puts "Reversed string: #{str}" }

puts result
# OLLEH

In this example, the yield_self method is used to transform the string to uppercase and then reverse it. The tap method is used to log the intermediate values of the string after each transformation. The final result is the reversed uppercase string "OLLEH", which is stored in the result variable.

V. Conclusion

In this article, we have discussed Ruby’s tap and yield_self methods and how they can be used to chain method calls and transform data in a functional programming style. tap is used to perform side effects on an object without affecting the method chain, while yield_self is used to transform the receiver object and return a new value in the method chain. By using tap and yield_self effectively, you can simplify your code and make it more readable.