Algebraic Effects

Definitions

1. A programming language feature where functions can 'perform' effects (I/O, exceptions, async, state) and a handler higher up the call stack decides how to interpret them. More composable than monads — effects can be freely combined without monad transformer stacks. Implemented in Koka, Eff, and influencing React's design (Suspense, hooks).

   In plain English: A way for functions to request side effects while letting the caller decide how to handle them — like customizable exceptions.

   Example: "With algebraic effects, the function performs a 'read file' effect — the handler decides whether to actually read the file or return test data."

Related Terms

• Continuation
• Cut
• Discriminated Union
• Pattern Matching
• Algebraic Data Type
• Referential Transparency
• Continuation
• Effect System