List-based Monadic Computations for Dynamically Typed Languages

In this paper we propose a flexible and elegant design for list-based monadic ("karmic") computations in dynamically typed languages. Our approach is applicable to any dynamically typed language that supports lists, maps and higher-order functions. The design results in a clear, concise and largely language-independent syntax. We prove that our design adheres to the laws governing monads. We illustrate the use of the list-based monads with three examples: error handling in computations, stateful computations and parser combinators. We provide examples in the popular multi-paradigm language Perl, the object-oriented language Ruby and the functional dynamically typed language LiveScript