sum-types topic
datatype99
Algebraic data types for C99
poica
🧮 A research programming language on top of C macros
adt
Algebraic data types for Python (experimental, not actively maintained)
sumtype
A namedtuple-style library for defining immutable sum types in Python.
fpGo
Monad, Functional Programming features for Golang
derive4j
Java 8 annotation processor and framework for deriving algebraic data types constructors, pattern-matching, folds, optics and typeclasses.
ImTools
Fast and memory-efficient immutable collections and helper data structures
scriptum
Functional Programming Unorthodoxly Adjusted to Client-/Server-side Javascript
recursive-variant
Recursive Variant: A simple library for Recursive Variant Types