Today I Learned

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Chaining `then` in Ruby 2.6

Ruby 2.5 introduced a method yield_self on an object. The idea is simple, just pass self as the argument to a block.

"something".yield_self {|str| str + "!"}
          .yield_self {|str| str + "!"}
# "something!!"

It yields self and returns the result of the block, unlike tap which yields self and returns self.

yield_self feels technical and wordy. Ruby 2.6 introduces an alias for yield_self, then. then feels like something that could mimic the pipe operator (|>) in Elixir. Data transformations can be just a series of thens.

"something"
.then {|str| str.chars.map {|x| x.ord + 1 }}
.then {|ords| ords.map {|x| x.chr }}
.then {|chars| chars.join } 
.then {|str| str + "!" }
.then {|str| str + "!" }
# tpnfuijoh!!

In some cases where a data transformation takes multiple steps, this coding style might make your could cleaner and more intentional.

I look forward to seeing then in your code!

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