Tezos and Functional Programming

OCaml, the language of the Tezos protocol

The Tezos protocol is written in OCaml, a general purpose industrial-strength programming language with an emphasis on expressiveness and safety. It is the technology of choice in companies where speed is crucial and a single mistake can cost millions. It has a large standard library, which makes it useful for many of the same applications as Python or Perl, and it has robust modular and object-oriented programming constructs that make it applicable for large-scale software engineering. Many top companies use OCaml, including Facebook, Bloomberg, Docker, and Jane Street.

OCaml Resources

What is functional programming? How is it different from other paradigms?

Functional programming is a programming paradigm — a style of building the structure and elements of computer programs — that treats computation as the evaluation of mathematical functions and avoids changing-state and mutable data.

It is a declarative programming paradigm, which means programming is done with expressions or declarations instead of statements. In functional code, the output value of a function depends only on the arguments that are passed to the function, so that calling a function f twice with the same value for an argument x produces the same result f(x) each time. This is in contrast to procedures that depend on a local or global state, which may produce different results at different times when called with the same arguments but a different program state. Eliminating side effects, i.e. changes in state that do not depend on the function inputs, can make it much easier to understand and predict the behavior of a program, which is one of the key motivations for the development of functional programming.

Here is a diagram that shows the high-level differences between the EVM (Ethereum Virtual Machine), WASM (Web Assembly) and Michelson: