Haskell is the world’s best programming language, but let’s face the harsh reality that a lot of times in life you’ll have to write in other programming languages. But alas you have been fully Haskell-brained and lost all ability to program unless it is type-directed, you don’t even know how to start writing a program without imagining its shape as a type first. Well, fear not. The foundational theory behind Algebraic Data Types and Generalized Algebraic Data Types (ADTs and GADTs) are so fundamental that they’ll fit (somewhat) seamlessly into whatever language you’re forced to write. After all, if they can fit profunctor optics in Microsoft’s Java code, the sky’s the limit! This is an “April Fools” joke in the tradition of my previous one in some of these ways that we are going to twist these other languages might seem unconventional or possibly ill-advised… but also the title is definitely a lie: these languages definitely should have them! :D