List processing library

Functional-Light-JS is a JavaScript functional programming library designed to implement functional patterns within JavaScript applications. It serves as a toolkit for declarative data processing, immutable data management, and the construction of complex logic through higher-order functions. The library focuses on a pragmatic implementation of functional programming, providing utilities for curried argument application and function composition. It emphasizes the use of pure functions to calculate state updates and manage application data without side effects. The project covers broad capabi

This is a persistent data structure library for JavaScript that provides collections which prevent the direct mutation of objects and arrays. It serves as an immutable state management tool and functional programming utility, ensuring that data remains unchanged after creation to simplify change detection and state tracking. The library enables the maintenance of application state by producing new versions of data structures during updates. It focuses on efficient data comparison by checking actual content instead of memory references and supports a functional programming workflow to prevent

Ramda is a functional JavaScript standard library and toolset for immutable data transformation and composition. It provides a comprehensive suite of pure utility functions designed to enable declarative data processing pipelines. The library is distinguished by its use of automatic function currying and a data-last argument order. These design patterns allow multi-argument functions to be partially applied, simplifying the construction of processing chains where data is passed through a sequence of operations. The toolkit covers broad data manipulation capabilities, including list processin

Lazy.js is a JavaScript library that implements a lazy evaluation model for processing collections and data streams. It defers all computation until iteration begins, building chains of transformations that execute only when values are consumed, avoiding intermediate arrays and buffering. The library wraps data sources into a uniform sequence interface, enabling operations like map and filter to be chained together without materializing intermediate results. The library extends lazy processing beyond simple collections to handle asynchronous data sources, DOM events, strings, and Node.js stre

Underscore is a JavaScript utility library providing a suite of functional programming and data manipulation helpers. It serves as a framework for transforming data collections, composing functions, managing objects, and performing precise data type validation without modifying core language prototypes. The project includes a functional programming toolkit designed to control function execution timing and behavior through techniques such as debouncing, throttling, and partial application. It also provides a dedicated object manipulation utility for cloning, merging, picking, and omitting prop

Immutable.js is a library of persistent data structures and a functional state management toolkit. It provides a collection of immutable objects and arrays that prevent direct mutation to ensure predictable state management in JavaScript applications. The library utilizes structural sharing to efficiently create new versions of data without full copying and implements lazy sequence processing to chain data transformations that execute only when values are requested. It also supports batch mutation processing, allowing multiple changes to be applied to a temporary mutable copy before returning

language-ext is a functional programming framework for C# that provides a suite of immutable data structures and monadic types. It enables the implementation of pure functional programming patterns, utilizing containers to manage side effects, optional values, and error handling. The library is distinguished by its advanced concurrency and state management tools, including a software transactional memory system and lock-free atomic references. It also provides specialized utilities for distributed systems, such as vector clocks for causality tracking and deterministic data conflict resolution

Lodash is a JavaScript utility library and data manipulation toolkit. It provides a collection of modular functions for transforming, filtering, and validating arrays, objects, strings, and numbers. The project functions as a functional programming toolkit, offering capabilities for function composition, currying, and lazy evaluation. It includes mechanisms for execution control, such as debouncing and throttling, to manage the timing and frequency of function invocations. The library covers a broad surface of data operations, including deep cloning and merging of complex nested structures,

Guava is a Java standard library extension and utility toolkit that provides optimized data structures, concurrency tools, and core extensions. It serves as a comprehensive set of helpers for Java development, focusing on reducing repetitive boilerplate logic. The project is distinguished by its specialized implementations of immutable collections, which ensure thread safety and data consistency by preventing accidental modification. It also includes a dedicated graph data structure library for modeling and traversing networks of interconnected nodes and edges, alongside advanced collection t

🐆 An immutable list with unmatched performance and a comprehensive functional API.

This project is a command-line processor designed for the parsing, filtering, and transformation of structured data streams. It functions as a declarative programming environment that treats data as immutable streams, allowing users to perform complex structural modifications through the composition of small, reusable functions. By utilizing a recursive tree traversal engine, the system enables the navigation, inspection, and modification of deeply nested hierarchical data structures. The engine distinguishes itself through a stream-oriented architecture that processes input records one by on

Scalaz is a functional programming library for Scala that provides a collection of purely functional data structures and type classes. It functions as a framework for organizing functional behaviors into hierarchies to enable generic programming and type-safe transformations. The library includes tools for composing and managing nested functional effects within a single type stack through a monad transformer system. It provides data structures for representing and combining input, output, and optionality effects. The project covers a broad surface of functional abstractions, including the im

Eclipse Collections is a collections framework for Java with optimized data structures and a rich, functional and fluent API.

jOOλ - The Missing Parts in Java 8 jOOλ improves the JDK libraries in areas where the Expert Group's focus was elsewhere. It adds tuple support, function support, and a lot of additional functionality around sequential Streams. The JDK 8's main efforts (default methods, lambdas, and the Stream API) were focused around maintaining backwards compatibility and implementing a functional API for parallelism.

Functional programming in Java

Kotlinx.collections.immutable is a persistent data structure library for Kotlin that provides immutable lists, sets, and maps for state management. It enforces strict immutability by exposing read-only interfaces that block unauthorized modifications at compile time, while persistent structural sharing allows modified copies to efficiently reuse underlying memory storage with the original collection. Multiple insertions and removals can be batched through temporary mutable builder interfaces to instantly produce new persistent collections without intermediate allocations. Additionally, stand