mcintyre321/OneOf
OneOf
OneOf is a C# discriminated union library and source generator that provides functional sum types. It serves as a strongly typed polymorphism tool, allowing developers to define method parameters and return values that can be exactly one of several specific types.
The project implements functional programming patterns to replace generic base classes with type-safe unions. It utilizes a source generator to automatically produce the boilerplate code required to manage these union type hierarchies during compilation.
The library provides mechanisms for pattern matching and union value extraction, featuring compile-time exhaustiveness enforcement to ensure every possible type case is handled in switch expressions. It supports reusable union type definitions and polymorphic API design through multi-type return signatures and parameter support.
Features
- Discriminated Unions - Provides a library for implementing tagged sum types (discriminated unions) in C# with safe runtime switching.
- C# Source Code Generators - Utilizes C# source generators to automatically produce the class hierarchies and metadata required for union types.
- Exhaustiveness Analysis - Analyzes switch expressions to ensure every member of a union is handled, triggering a compiler error for missing cases.
- Union State Matching - Provides mechanisms to execute specific handler functions based on the active variant of a union type.
- Exhaustive Pattern Matches - Enforces that all variants of a union are handled in pattern matches, providing warnings or errors for incomplete cases.
- Container Value Matching - Allows the extraction of values from multi-type containers using structural matching and switch blocks.
- Type-Safe Discriminated Unions - Implements discriminated unions in C# to ensure every possible type is handled at compile time during pattern matching.
- Union Types - Provides a utility to generate C# union types that can represent any one of several specified member types.
- Closed Class Hierarchies - Implements closed class hierarchies via source generation to restrict the possible types within a union.
- Strongly Typed Polymorphism - Provides a mechanism for defining method parameters and return values that can be exactly one of several specific types.
- Sum Type Wrappers - Wraps multiple potential types in a single object that preserves type safety while allowing polymorphic value retrieval.
- Sum Type Return Values - Provides the capability to return a value that can be any one of several predefined specific types.
- Sum Type Returns - Enables functions to return one of several distinct types, replacing generic base classes with strongly typed signatures.
- Functional Programming Patterns - Brings F#-style algebraic data types and functional programming paradigms into the imperative C# environment.
- Union Type Parameters - Allows methods to accept one of several different types as a parameter, reducing the need for multiple method overloads.
- Polymorphic API Signatures - Enables method signatures that accept or return one of several specific types without relying on generic base classes.
- Algorithms and Data Structures - Provides discriminated unions with compile-time exhaustive matching.
