Semantics of value recursion for Monadic Input/Output
OGI School of Science and Engineering, OHSU;
2 Galois Connections, Inc.
Monads have been employed in programming languages for modeling various language features, most importantly those that involve side effects. In particular, Haskell's IO monad provides access to I/O operations and mutable variables, without compromising referential transparency. Cyclic definitions that involve monadic computations give rise to the concept of value-recursion, where the fixed-point computation takes place only over the values, without repeating or losing effects. In this paper, we describe a semantics for a lazy language based on Haskell, supporting monadic I/O, mutable variables, usual recursive definitions, and value recursion. Our semantics is composed of two layers: a natural semantics for the functional layer, and a labeled transition semantics for the IO layer.
Mathematics Subject Classification: 68N18 / 68Q55 / 18C15
© EDP Sciences, 2002