Refactoring functional languages. This focus serves to keep our work concrete and practical, not to exclude other functional languages. Abstract Elixir is a modern functional language known for its robustness and scalability. Haskell is the principal lazy functional programming language, and its main implementation, the Glasgow Haskell Compiler, is a UK product (whose original implementations were supported by EPSRC funding). They define a common language that helps your team communicate more efficiently. Original Agile Manifesto signer and software development thought leader, Martin Fowler, provides a catalog of refactorings that explains why you should refactor; how to recognize code that needs refactoring; and how to actually do it successfully, no 1999: the practice of “refactoring”, incorporated a few years earlier into Extreme Programming, is popularized by Martin Fowler’s book of the same name 2001: refactoring “crosses the Rubicon “, an expression of Martin Fowler describing the wide availability of automated aids to refactoring in IDEs for the language Java Academic Apr 30, 2025 · Code refactoring is a software development practice that alters the internal structure of software code without modifying its external behavior or impacting its functionality. In this paper we explore the prospects for refactoring functional programs. We report on the experience of tool building, contrast the two tools, and these tools with their OO equivalents. Jul 5, 2025 · When and Why to Rewrite OOP Code in Functional Style Rewriting a large object-oriented programming (OOP) codebase into a functional programming (FP) style is a bold and often controversial move in software engineering. Jan 21, 2025 · Code refactoring involves restructuring existing code to improve its structure and readability. The core of the paper outlines the main challenges that arise from the aim to produce practical tools for a decidedly non-toy language, and summarizes the experience in trying to establish the necessary meta-programming infrastructure and gives an implementation overview of the current prototype refactoring tool. Code refactoring is a process that involves removing duplicate code, patches, and other issues from the code repository. It Feb 15, 2023 · Published at February 15, 2023 Tutorials Example of a functional programming refactoring pattern In this post we'll demonstrate an example of a functional refactoring pattern. Its heart is a series of small behavior preserving transformations. HaRe and Using this data, we measure the ratio of refactoring vs refuctoring for a series of popular AI models: Table 1: Benchmarking of refactoring correctness for a series of popular Large Language Models. FP is not in conflict with OOP. AI-Powered Higher Education: Navigating Federal Student Aid, Programming Languages, and the Future of Software Development - fully visualized data of colleges rankings, basic information, admission, graduation, tuition, majors, students, campus safety and more information. I am wondering if some similar texts or resources focus on the functional style of code refactoring and reusability. uk Abstract We demonstrate the Haskell Refactorer, HaRe, and the Erlang Refactorer, Wrangler, as examples of fully-functional refactoring tools for functional programming languages. External links Some of the work being done in functional languages, and Haskell in particular: Refactoring Functional Programs aka the refactor-fp project Generic refactoring in 3 Towards generic, language-independent refactorings Refactoring has a very different character in different programming languages; to take one example, [11] compares refactoring in two functional programming languages: Haskell and Erlang. In this way, refactoring is Jan 4, 2024 · Refactoring is the process of restructuring existing code to improve its quality, maintainability, and readability. Refactoring is important for many reasons, with the main reason being to improve the code's design and maintainability. Checklist of refactoring done right way The code should become cleaner. This eagerly awaited new edition has been fully updated to reflect crucial changes in the programming landscape. Li@kent. Apr 1, 2025 · Review and compare the popular Functional Programming Languages with features, pros, and cons in this tutorial. Refactoring in object-oriented languages has been well studied, but functional languages have received much less attention. Functional aspects are composed by function composition. 5 Functional Programming: A Summary For our purposes, the principles of the functional programming paradigm are as follows: Computation consists in the evaluation of functions. They are embedded in Emacs (and gVim) and respect programmer layout styles. Secondly, we introduce and investigate the concepts of functional refactoring in the context of a small case study, refactoring a 400 line student program. Your mission is to remove every effects (aka computational context) within the applyDiscount function with the power of Functional Structures. This post includes examples with inheritance and functional interfaces. In this comprehensive guide, we’ll explore the art of refactoring, discussing its Refactoring code is a programming technique used to improve legacy software's quality, maintainability, and efficiency as an alternative to rewriting. Starting code for the GildedRose Refactoring Kata in many programming languages. NET and F#, when they have a comparative advantage over the languages that everyone is familiar with: Java, C++, and C#. Jul 15, 2022 · Java 8 added functional programming capabilities, but when it comes to really writing Java code in a functional style, you may need a guide. Below, we walk through each stage of this evolution: Wave 1: Code creation & autonomous assistance (2020–present) Early tools: code autocomplete & assistance (2020–2021 Multi-Agent Refactoring in Functional Languages for Empowered Software Development. Your scripts will only be a sequence of calls to these functions, making them easier to understand. We recommend you to read this book if you want to go in-depth with the code refactoring process. Each approach has its own set of principles and techniques to improve code quality and maintainability. Tool Support for Refactoring Functional Programs Huiqing Li Simon Thompson Computing Laboratory, University of Kent, UK H. Has functional programming really mattered? Our answer is a resounding ‘Yes!’. In the ever-evolving world of software development, maintaining and improving existing code is just as crucial as writing new code. See Also Introduction to refactoring Code refactoring Nov 20, 2023 · A less complex and more straightforward program is a crucial factor that enhances its maintainability and makes writing secure and bug-free programs easier. By embracing refactoring, teams can: Eliminate technical debt Streamline their workflows Ultimately Abstract. The aim of our research is bring the advantages of refactoring to functional programmers, with a specific focus on support for Haskell programmers. Jan 4, 2025 · In the world of programming, refactoring code to make it more efficient, readable, and maintainable is a regular task for developers. This paper presents our ideas about refactoring in Erlang, a functional programming language developed by Ericsson for Refactoring tools for functional languages295 program development, evolution and maintenance. / Electronic Notes in Theoretical Computer Science 141 (2005) 29 3434 lations is a layout adjustment algorithm which keeps the program’s layout correct whenever the token stream has been updated. Ideally, refactoring is about the internal structure and shouldn’t change external behavior, and performance is part of the behavior. e. Mar 2, 2021 · In this guide, you’ll learn all about refactoring source code: the benefits, challenges, tools, and best practices, and what is the difference between refactoring and technical debt. However in object oriented languages the same goal can be reached more elegantly by using polymorphism. Sep 21, 2025 · The shift toward AI-enabled development Software development is no longer just about code autocomplete. Expand 75 PDF 1 Excerpt Dive Into Refactoring teaches you how to properly deal with legacy code, how to identify ugly code and how to clean it safely. The core of the paper then outlines the main challenges that arise from our aim to produce practical tools for a decidedly non-toy language, summarizes our experience in trying to establish the necessary meta-programming infrastructure and gives In computer programming and software design, code refactoring is the process of restructuring existing source code —changing the factoring —without changing its external behavior. This paper reflects on our experience of building tools to refactor functional programs written in Haskell (HaRe) and Erlang (Wrangler). Jul 11, 2025 · Advantages of Functional Programming Pure functions are easier to understand because they don’t change any states and depend only on the input given to them. Jan 8, 2019 · A nice introduction to functional concepts for programmers used to an imperative style. Despite this fact, and to the best of our knowledge, there are few works in the literature focused on studying refactoring strategies for code implemented with this language. We present the Haskell Refactorer, HaRe, and the Erlang Refactorer, Wrangler, as examples of fully-functional refactoring tools for functional programming languages. Many refactoring operations are application domain-neutral and are applied whenever transforming between any procedural and any object-oriented language. In this paper, we explore functional aspects in the context of aspect-oriented refactoring. This comprehensive guide delves into the intricacies of functional language, unraveling its fundamental principles, key features, and transformative impact on the software In computer programming and software design, code refactoring is the process of restructuring existing computer code—changing the factoring—without changing its external behavior. Refactoring Functional Programs Experience of building refactoring tools for Haskell and Erlang We have built tools for refactoring programs written in the functional languages Haskell and Erlang. Computing Laboratory University of Kent, UK S. Our sample of two languages – Haskell and Erlang – shows the breadth of the category ‘functional’; here we briefly recall the differences between these two. In software development, LLMs can enhance the coding experience through coding automation, reducing development time and improving code quality. Change to new methodology is thoughtful and probably slow, except when a revolution happens but then, its still respectful to the new culture. Nice! But what’s clean code, anyway? Here are some of its features: Clean code is obvious for other programmers. The goal is to cleanse the internal structure of the code, making it more readable, maintainable, and efficient, while preserving its inherent functionality. That’s where codemods come in Although recent advancements have leveraged Large Language Models (LLMs) to automate refactoring tasks, current solutions are constrained in scope and lack mechanisms to guarantee code compilability and successful test execution. Design Patterns are typical solutions to the commonly occurring problems in software design. Refactoring is the process of improving the design of exist-ing programs without changing their functionality. Code refactoring is a technique used to enhance the internal quality of the code base without Mar 6, 2024 · The goal of refactoring is to improve code readability and simplify complexity. Nov 30, 2023 · In traditional languages like COBOL, GenAI can breathe new life into legacy systems. alog refactoring strategies compatible with Elixir. Refactoring is a process of improving your source code without creating a new functionality. Sep 9, 2024 · Refactoring is a common task in writing and maintaining software. H. Refactoring stands at the forefront of this endeavor, offering developers a systematic approach to enhance code quality without altering its functionality. Correct-by-construction refactoring of functional code Provided by Programming Languages for the Research Project 2022/2023 Q4 course. Much of refactoring is devoted to correctly composing methods. In functional programming, your code is organised into functions that perform the operations you need. Most are applicable to a variety of modern functional programming languages – with the example code begin written in Haskell – but some relate specifically to Haskell and are marked as such. May 11, 2022 · Learn how you can achieve better design using object-oriented and functional approaches. When a refactoring is applied to a gram, the transformation is effected only if all the preconditions are satisfied by the program. This article is meant to describe it briefly; however, the best way to understand functional programming is to learn the basics of one of the functional programming languages (such as Haskell). The UI elements and VS Code commands for refactoring are the same across the different languages. - emilybache/GildedRose-Refactoring-Kata Feb 9, 2014 · Simon Thompson shows the particularities of functional programming refactoring through examples in Haskell and Erlang, and discusses what lays ahead for FP refactoring in the next 10 years. Refactoring has recently come to prominence in the OO community. We might program in an exploratory way: first establishing the functionality we seek, and then refactoring into a more elegant form. uk Abstract. In the context of functional languages, refactor Abstract. Refactoring Functional Programs - Abstract. We propose a method to leverage the prompting with few-shot examples of the LLM by selecting the best-suited code refactoring examples for each target programming The current (second) release of Wrangler Classifications—Applicative (functional) languages; Concurrent, works with the complete Erlang/OTP language, and supports a few distributed, and parallel languages; D. Oct 16, 2023 · Functional Languages and Libraries The availability of functional programming languages and libraries, such as R, Haskell, Scala, Clojure, and Elixir, has made it easier for developers to embrace the principles of functional programming. Definition of Functional Programming The introduction to The Joy of Clojure says the following: Functional programming is one of those computing terms that has a amorphous definition. If you ask 100 programmers for their definition, you’ll likely receive 100 different answers Functional programming concerns and facilitates the application and composition of functions For a language to Our paper centres on the case study of refactoring a 400 line Haskell program written by one of our students. Refactoring is a controllable process of improving code without creating new functionality. However, refactoring involves tradeoffs between different factors, and it can be challenging to balance these tradeoffs in Code refactoring is the process of improving the internal structure, readability, and maintainability of a software codebase without altering its external behavior or functionality. ABSTRACT We present the Haskell Refactorer, HaRe, and the Erlang Refactorer, Wrangler, as examples of fully-functional refactoring tools for functional programming languages. Often, discussions and tutorials about refactoring focus on object-oriented languages. Code refactoring makes these code blocks concise, precise, and clearly communicates the developer In our project ‘Refactoring Functional Programs’1, we seek both to complement existing work on refactoring with a functional pro-gramming perspective and to make refactoring techniques and tools available to functional programmers. In a preliminary and previous study, we conducted a So you could argue that Javascript is less functional than Java, in many ways. Each chapter includes examples in Java, C# and PHP. A guide to when & why refactoring application code regularly is essential and how to advocate its importance to engineering teams. It relies on fully automated refactoring by preserving the investment in business functions. A novelty of the presented approach is that programs are represented, stored and manipulated in a relational database. Their function signature gives all the information about them i. They are embedded in Emacs, (gVim and Eclipse) and respect programmer layout styles. By improving maintainability, performance, functionality, and testability, refactoring can help developers write more reliable and maintainable code. These notes cover refactoring in functional languages, using Haskell as the medium, and introducing the HaRe tool for refactoring in Haskell. While the challenges are significant—including a steep learning curve, possible disruptions to productivity, and the complexity of transitioning a live system—the rewards I am currently reading Refactoring - Improving the Design of Existing Code by Martin Fowler to get a better understanding of things I've come to learn from practice and experience in a more well-presented context. The course covers 21 smells of bad code and 66 refactoring techniques to fix them. Dec 6, 2024 · This is where automated refactoring tools step in, offering a structured, efficient, and reliable way to modernize your COBOL applications. Sep 11, 2025 · For example, a common refactoring used to avoid duplicating code (a maintenance headache) is the Extract Method refactoring, where you select source code and pull it out into its own shared method, so that can reuse the code elsewhere. If the code remains just as unclean after refactoring well, I’m sorry, but you’ve just wasted an hour of your life. However, due to its heavy workload and the risks of breaking the working programs, programmers are reluctant to do code refactoring, and thus, it also causes the loss of potential learning experiences. Apr 18, 2023 · AWS Blu Age uses automated refactoring patterns within the AWS Mainframe Modernization service. Refactoring Without Breaking Performance A common concern when refactoring is whether these cleaner code changes will make my system slower or more resource-hungry. So when should code be refactored? This is a common question that software Aug 20, 2024 · Good refactoring respects the idioms of the language and the culture of the organisation. Jun 1, 2018 · Refactoring is a disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior. This process, known as refactoring, is an essential skill for any programmer looking to enhance their abilities and create more efficient, readable, and maintainable software. In this work, we introduce MANTRA, a comprehensive LLM agent-based framework that automates method-level refactoring. Jun 1, 2012 · We present the Haskell Refactorer, HaRe, and the Erlang Refactorer, Wrangler, as examples of fully-functional refactoring tools for functional programming languages. We show that refactoring legacy applications using functional aspects is just as flexible and Some refactoring operations must be done prior to others to establish the appropriate state of the software model for subsequent refactoring operations. Finally, we present some preliminary conclusions and outline our approach towards improving support for refactoring in functional languages. Refactoring involves making small changes to improve the internal structure of the code without affecting its external behavior. Functional programming is now at the forefront of a new generation of programming technologies, and Abstract. In the context of functional languages, refactor The UK is a world leader in functional programming re-search. In his 1978 (!) Mar 26, 2025 · Refactoring involves transforming existing mainframe applications (often written in COBOL, Assembler and other legacy languages) into modern languages and architectures, typically Java or C# running on cloud-native platforms and services, through rule-based transformation. HaRe and Wrangler are designed to handle multi-module projects in complete languages: Haskell 98 and Erlang/OTP. Oct 19, 2008 · Abstract and Figures We present the Haskell Refactorer, HaRe, and the Erlang Refactorer, Wrangler, as examples of fully-functional refac- toring tools for functional programming languages. Nov 4, 2024 · Abstract. Clean code The main purpose of refactoring is to fight technical debt. More than two decades have passed. Dec 8, 2023 · Uncover the essentials of code refactoring: learn its benefits, key techniques, and best practices to enhance your coding efficiency. Subreddit for the Elixir programming language, a dynamic, functional language designed for building scalable… May 21, 2025 · 7. We designed and implemented LambdaFicator, a tool which automates two refactorings. While IDEs can handle simple refactorings with just a few keystrokes, things get tricky when you need to apply changes across large or distributed codebases, especially those you don’t fully control. Jul 15, 2025 · They have also written a complete book on this subject Refactoring: Improving the Design of Existing Code. ac. I am not aware of any programming language that does this automatically, but (manually) creating memoized functions is possible in common functional languages like Clojure and Haskell. Refactoring is the process of improving the design of exist- ing programs without changing their functionality. Abstract We demonstrate the Haskell Refactorer, HaRe, and the Erlang Refactorer, Wrangler, as examples of fully-functional refactoring tools for functional programming languages. In 9 open-source projects we have applied these two refactorings 1263 and 1595 times, respectively. Mar 5, 2023 · To me, FP in modern functional languages provides abstractions that enable much more straightforward problem solving and understandable code with fearless refactoring. There are several techniques and best practices for effective code refactoring. These notes cover refactoring in Fearless refactoring The compiler guides you safely through your changes, ensuring confidence even through the most widereaching refactorings in unfamiliar codebases. This paper reflects on our experience of building tools to refactor functional programs written in Haskell (HaRe) and Erlang (Wrangler). Refactoring, Second Edition, features an updated catalog of refactoring's and includes JavaScript code examples, as well as new functional examples that demonstrate refactoring without classes. By refactoring and optimizing existing COBOL code, GenAI can improve the performance and maintainability of these systems. Try to figure out why We begin by discussing what refactoring means for functional programming languages, first in theory, and then in the context of a larger example. Dec 12, 2005 · Thompson, S. Refactoring is a disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior. What is Refactoring? Sep 7, 2024 · Refactoring is a common task in writing and maintaining software. NET, SML. Refactoring is an essential technique for improving the quality and maintainability of code in object-oriented programming. Dec 21, 2023 · Get Author by id All the above codes are very old I tried refactoring it to be more functional way instead of a lot of branching {} and if statements. Whatever output they produce is the return value they give. In particular, R has what’s known as first class functions. Despite this fact, and to the best of our knowledge, there are few works in the literature focused on studying refactoring strategies for code implemented with this Chapter 8 Functional programming Functional programming is a paradigm that I find very suitable for data science. " There will always be some differences across language environments, so I have tried to keep the book’s lessons broad, and we’ll see where it goes from there. It can convert languages like COBOL, PL/1, NATURAL, RPG/400, and COBOL/400 into agile Java services and web frameworks. Aug 13, 2025 · Introduction In the ever-evolving landscape of software development, the importance of clean, maintainable code cannot be overstated. Similarly to other program transformations, refactorings are based on program equivalences, and thus ulti-mately on language semantics. 6 days ago · In this post we'll demonstrate an example of a functional refactoring pattern. Good starting points are small interfaces with few imperative dependencies. uk Computing Laboratory, University of Kent, UK S. We begin by discussing what refactoring means for functional programming languages, first in theory, and then in the context of a larger example. New features are difficult to add: When existing code doesn’t easily accommodate updates, refactoring can pave the way for smooth integration. Refactorings are provided by a language service. Learn what do you need to know about refactoring. The mantra of refactoring is clean code and simple design. com/. The success of modern functional programming languages like Clojure, F# and Scala is a consequence of their ability to coexist with object oriented platforms like the JVM and the CLR. Simon Thompson Computing Laboratory University of Kent, UK S. Far more than you ever wanted to know about refactoring at http://www. "The general technique of refactoring is completely applicable across functional languages. Bloaters are code, methods and classes that have increased to such gargantuan proportions that they are hard to work with. Two typical refactoring scenarios are: adapting the structure of an existing code base to prepare for adding functionality or fixing a bug; cleaning up a code base after extensive functional changes. Mar 25, 2022 · Why do programmers regularly rewrite other people's ready-made code without adding new functions? It is all about refactoring. However, even though most refactoring tools are designed with this criterion in mind, and programmers expect it, their 3 Towards generic, language-independent refactorings Refactoring has a very different character in different programming languages; to take one example, [11] compares refactoring in two functional programming languages: Haskell and Erlang. This is distinct from other modernization patterns such as replatforming, which focuses on infrastructure changes, or Dec 15, 2024 · Context-Aware Method — allows the refactoring tool to understand the semantics of the programming language and build a comprehensive understanding of the program’s source code before deciding Since you will be refactoring an existing codebase, start by identifying existing logical interfaces in your code that can be cleanly moved to a functional style. Similarly to other program transformations, refactor-ings are based on program equivalences, and thus ultimately on lan-guage semantics. Each transformation (called a “refactoring”) does little, but a sequence of these transformations can produce a significant restructuring. Sep 10, 2020 · If I am writing in a functional style and want to use the Replace Conditional with Composition refactoring pattern on a switch or a long chain of if/else if/else if/, how do I approach it? Secondly, we introduce and investigate the concepts of functional refactoring in the context of a small case study, refactoring a 400 line student program. Code refactoring is the process of restructuring to improve the existing code without changing its external behavior. Dec 18, 2023 · Meanwhile, languages such as JavaScript and Python, traditionally known for their imperative and object-oriented paradigms, have increasingly adopted functional capabilities. Jul 7, 2025 · We present the Haskell Refactorer, HaRe, and the Erlang Refactorer, Wrangler, as examples of fully-functional refactoring tools for functional programming languages. , Clojure, Erlang, Haskell, and Lisp), as well as languages that inspired the creation of Elixir, such as Ruby. However, manually rewriting thousands of lines of COBOL code is time-consuming, error-prone, and costly. 14. The term ‘refactoring’ was popularised by the book of the same name (Fowler, 1999), but this form of program restructuring has surely gone on ever since programs have been written. Take Clojure for an example. What is distinctive about refactoring functional programs? In order to answer this, we first have to examine in a Jan 25, 2017 · What Functional Programming is Not Helper Methods Writing Things in Haskell Compile-time AST Macros Static Types Step by Step Imperative Recipes Kitchen Refactoring Functional Programming Recipes Tiramisu Diagram to Functional Programming Preventing Errors with Functional Programming Refactoring a Functional Tiramisu Recipe The Core of Functional Programming Conclusion A topic as broad as Abstract. The catalog of annotated code examples of all design patterns, written in Python. As the preceding table shows, using an out-of-the-box AI is very much a hit-or-miss situation. Software engineering is an ever-evolving field, and code needs to keep up with the pace of change. To mitigate this, we demonstrate the In this guide, you’ll learn all about refactoring source code: the benefits, challenges, tools, and best practices, and what is the difference between refactoring and technical debt. Learn how to use ChatGPT to help. The second refactoring converts for loops that iterate over Collections to functional operations that use lambda expressions. Get started now! May 9, 2025 · What is code refactoring and review the impact of refactoring code on various project team members. On the other hand, rewriting code means starting fresh and creating an entirely new codebase while retaining the same or similar Mar 28, 2025 · Explore what a functional computer language is, see the features common to them, and discover the different examples of functional programming languages. The extension provides refactoring tools for your React codebase: extract JSX into a new component, convert Class Components to Functional Components, wrapping with Hooks and more! Thirdly, we present some preliminary conclusions and outline our approach towards im- proving support for refactoring in functional languages. Despite this fact, and to the best of our knowledge, there are few works in the literature focused on studying refactoring strategies for code implemented with this We begin by discussing what refactoring means for functional programming languages, first in theory, and then in the context of a larger example. The refactoring techniques in this group streamline methods, remove code duplication, and pave the way for future Mar 21, 2014 · Refactoring Functional Programs Simon Thompson and Claus Reinke Technical Report 16-01, University of Kent, Computing Laboratory, October 2001. , Clojure, Erlang, Haskell, and Lisp), as well as languages. And I’m not talking about super sophisticated algorithms. their return type and their arguments. Application programming requires developers to write code blocks that interact with each other and with external systems so the application functions properly. Refactoring is the controllable process of systematically improving your code without writing new functionality. They offer unique features and benefits, but they also come with their set of challenges. Learn when and why it's essential for improving your codebase. Reinke, A Case Study in Refactoring Functional Programs,in:Brazilian Symposium on Programming Languages, 2003. Code refactoring leads to cleaner, more maintainable code. Jul 14, 2025 · Functional programming is a style of programming which models computations as the evaluation of expressions. Michael Stal gives one reason for refactoring, improving the future evolvability, but refactoring can target other non-functional requirements as well. In this comprehensive guide, we will explore the art and science of refactoring code, providing practical strategies, techniques, and best Oct 19, 2008 · We present the Haskell Refactorer, HaRe, and the Erlang Refactorer, Wrangler, as examples of fully-functional refactoring tools for functional programming languages. J. This demonstrates the capability to define adhoc anonymous implementations which do not need to be housed in a type of it’s own, thereby reducing Functional programming R, at its heart, is a functional programming (FP) language. A number of refactoring transfor-mations exist for different programming languages and pro-gramming paradigms, such as object-oriented programming-languages [9][10], functional programming-languages [11], and relational schemata [12]. A surprising amount of code may already be functional style. We suspect that functional languages are particularly suited to this form of programming, because their clean semantic basis makes wholesale transformations more feasible than for a language in the C family, say. Jul 14, 2015 · 1 Switch statements as case differentiation do have a real use. Refactorings are source-to-source program transformations that change program structure and organisation, but not program functionality. Oct 3, 2019 · A purely functional programming language, could technically cache any function result using its respective input arguments as cache key. If you don't do it for a long time, your work eventually becomes uncomfortable. The idea of continuous design improvement. refactoring. Nov 30, 2021 · An article showcasing Functional Programming Languages List and explaining in detail the top 16 Functional Programming Languages to learn. May 7, 2025 · Elixir is a modern functional language known for its robustness and scalability. Thirdly, we present some preliminary conclusions and outline our approach towards im- proving support for refactoring in functional languages. Documented in catalogues and supported by tools Refactorings are used to improve the maintainability and extensibility of a code base. Typical refactorings, such as function Code refactoring is the process of improving code structures to enhance readability and understanding without changing its functionality. Functional languages differ from object-oriented languages in their theory and practice so that an investigation of refactoring in the context of functional languages promises results at two lev-els. 1 Introduction Oct 16, 2023 · The availability of functional programming languages and libraries, such as R, Haskell, Scala, Clojure, and Elixir, has made it easier for developers to embrace the principles of functional programming. In most cases, excessively long methods are the root of all evil. This guide explains effective code refactoring techniques and best practices to maintain clean, readable, and maintainable codebases. Thompson@kent. Because of this, the first author was always sceptical about a language-independent approach to refactoring. Like Venkat. Other activity spon-sored by EPSRC in this area includes Runciman and Chitil’s work on tracing and debugging, and the resource Refactoring is the process of improving the design of existing programs without changing their functionality. Nov 30, 2018 · This eagerly awaited new edition has been fully updated to reflect crucial changes in the programming landscape. Haskell, Lisp, and Erlang are prime examples of such languages. Next, we address system design and details of system implementation as well as contrasting the style of refactoring and tooling for Haskell and Erlang. 4 []: Processors structural refactorings, such as rename an identifier, generalise a function definition, function extraction, move a Claus Reinke's 13 research works with 100 citations and 394 reads, including: Refactoring Functional Programs at the University of Kent. Our paper Jul 13, 2015 · Abstract In 1989 when functional programming was still considered a niche topic, Hughes wrote a visionary paper arguing convincingly ‘why functional programming matters’. The case study illustrates the type and variety of program manipulations involved in refactoring. As teams add changes and features to any form of software, there always arises the opportunity to refactor. 3. Functional programming languages use something called pattern matching which allows you to define functions differently depending on the input. Dec 18, 2019 · Refactoring using functional programming techniques. Li et al. May 7, 2025 · We found 54 refactorings that have been proposed for other functional languages (i. The results show that LAMBDAFICATOR is ly identify and enact refactoring opportunities of non-idiomatic code into idiomatic ones. Refactorings differ from other sorts of program transformation in being applied to source code, rather than to a ‘core’ language within a Apr 20, 2020 · Refactoring is the process of incrementally improving the design of software. Typical refactorings, such as function extraction and generalisation, are intended to make a program more amenable to extension, more comprehensible and so on. Now the main class will look like this: The main class creates an object of type ExtractReplace by passing an implementation of ResourceHandler Interface via the Lambda construct as seen. 2. This is also the level where this catalog is aimed at. The second refactoring converts for loops that iterate over Collections to functional oper-ations that use lambda expressions. The vagaries of code inside these methods conceal the execution logic and make the method extremely hard to understand—and even harder to change. One paradigm shift that has gained traction over the years is the transition from traditional iterative logic to functional pipelines. Building Refactoring Tools for Functional Languages Simon Thompson and Huiqing Li University of Kent, UK Java Refactoring Techniques Refactoring Java code can be approached in various ways, with two prominent paradigms being the object-oriented (OO) approach and the Functional approach. Poor variable naming, bloated classes and methods, magic numbers -you name it- all of that Refactoring is the process of improving the design of existing programs without changing their functionality. . Given the potential recently offered by Large Language Models (LLMs) for code-related tasks, in this paper, we present the results of a replication study in which we in To fill this gap, in this paper, we conduct an empirical study to investigate the potential of LLMs in automated software refactoring, focusing on the identification of refactoring opportunities and the recommendation of refactoring solutions. Key Features of Automated Refactoring Tools Automated Code Translation: These tools convert COBOL code into modern languages such as Java or C# while preserving the original business logic. May 1, 2013 · Request PDF | Refactoring tools for functional languages | Refactoring is the process of changing the design of a program without changing what it does. It has evolved from basic code autosuggestions to automated software testing and code migrating & refactoring, etc. R is not a pure functional programming language, so we need some self Abstract. Refactoring is intended to improve the design, structure, and/or implementation of the software (its non-functional attributes), while preserving its functionality. The goal of refactoring is to pay off technical debt. Since each refactoring is This paper reflects on our experience of building tools to refactor functional programs written in Haskell (HaRe) and Erlang (Wrangler). Feb 17, 2016 · Key Takeaways Pure functions are essential in functional programming as they return the same output for the same input without causing side effects, enhancing predictability and testability In functional programming, functions ARE data, and procedures are just function calls. 5, to suggest less complex versions of the user-written Python program, aiming to encourage users to learn how to write better programs. Refactoring helps reduce technical debt in software development. Feb 20, 2025 · Learn why code refactoring is essential for clean, scalable software, and discover best practices to maintain and evolve your codebase. This language has seen a growing adoption by companies worldwide in the last 12 years. Refactoring code is an essential practice for any developer who wants to maintain clean, efficient, and sustainable software. Refactoring also helps in getting buy-in from stakeholders for repaying technical debt by quantifying and visualizing the debt, demonstrating the viability of refactoring, and adopting best practices such as planning refactoring on a smaller scale, automating tests, and allocating sufficient buffer time for refactoring tasks. The starting code (provided in different languages) implements a use case with an imperative approach. It can also assist in converting COBOL code to more modern languages, such as Java, providing a valuable tool in system modernization efforts. Abstract Refactoring is the process of redesigning existing code without changing its functionality. A refactoring is composed of a collection of preconditions and program transformation. It transforms a mess into clean code and simple design. How to refactor Refactoring should be done as a series of small changes, each of which makes the existing code slightly better while still leaving the program in working order. and C. It improves extensibility, maintainability, and readability of software without changing what it Code refactoring is the process of changing a computer program's internal structure without modifying its external functional behavior or existing functionality, in order to improve internal non-functional properties of the software, for example to improve code readability, to simplify code structure, to change code to adhere to a given May 7, 2025 · Abstract Elixir is a modern functional language known for its robustness and scalability. Springer Verlag, September 2005. As codebases grow and evolve, they often accumulate technical debt, become harder to understand, and more difficult to extend. Refactoring is the process of improving the design of existing programs without changing their functionality. Olaf Zimmermann [Zimmermann 2015] defines an Architectural Refactoring as 1 Introduction Functional programming languages often provide programmers with higher-order reusable components to achieve functionality like mapping a function over a list. *A fine-tuned model based on CodeLlama 34B. 30K subscribers in the elixir community. Jan 1, 2007 · The paper analyses the language constructs of Erlang with respect to refactoring. Functional languages, as we define them, are a distinctive category in the programming world. Refactoring tools are available for a wide variety of programming languages, and they are intended to transform source code without altering the functional behaviour of the software being refactored. The first refactoring converts anonymous inner classes to lambda expressions. We found 54 refactorings that have been proposed for other functional languages (i. Functions are first-class citizens in the language. Our other publications about Wrangler are listed here. It helps you keep your code solid, dry, and easy to maintain. Refactoring is a critical aspect of software engineering and is essential for the evolution of code. The ability of functional programming languages to treat functions as These models are capable of translating code between languages, refactoring legacy code, and generating documentation with minimal human input, ultimately reducing development time and boosting productivity. Research Questions RQ1 - How do LLMs make refactoring existing software more advantageous than starting development from scratch? are LLMs in bridging the gap between functional languages like Haskell The first refactoring converts anonymous inner classes to lambda expressions. Jan 22, 2025 · Refactoring with Codemods to Automate API Changes Refactoring is something developers do all the time—making code easier to understand, maintain, and extend. Finally, we give a brief overview of the progress of our project thus far, as described in substantial detail in our paper [10]. This means that it provides many tools for the creation and manipulation of functions. Usually these smells do not crop up right away, rather they accumulate over time as the program evolves (and especially when nobody makes an effort to eradicate them). Feb 9, 2024 · Code refactoring is not merely an optional step in the software development process but an essential practice for building the best software. Abstract Refactoring is the process of improving the design of existing programs without changing their functionality. It is intended to change the implementation, definition, structure of code without changing functionality of software. Nov 20, 2018 · Refactoring improves the design of existing code and enhances software maintainability, as well as making existing code easier to understand. 3 Towards generic, language-independent refactorings Refactoring has a very different character in different programming languages; to take one example, [8] compares refactoring in two functional programming languages: Haskell and Erlang. We have written a paper on Refactoring tools for functional languages, which covers a lot of the background to the development of Wrangler and refactoring for Erlang. These languages prioritize the use of pure functions, immutability, and a declarative style of coding. The results show that LAMBDAFICATOR is This refactoring kata aims to let you practice with one of the main functional programming building block: Functional Structures. This document is the first draft of a catalogue of refactorings for functional programs. Developing a refactoring tool for a real-world popular functional language not only provides us with a framework for exploring the prospects of refactoring functional programs, but also makes refac-toring techniques and tools available to functional programmers. I like the focus on examples in two languages. 1 Introduction These notes cover refactoring in functional languages, using Haskell as the medium, and introducing the HaRe tool for refactoring in Haskell. Apr 3, 2025 · Refactoring or Code Refactoring is defined as systematic process of improving existing computer code, without adding new functionality or changing external behaviour of the code. Sep 25, 2024 · What is functional language – In the realm of computer science, the concept of functional language stands as a beacon of innovation, promising a paradigm shift that revolutionizes the way we approach programming. Since each refactoring is Refactoring is the process of changing the design of a program without changing what it does. The rst refactoring converts anonymous inner classes to lambda expressions. Sep 21, 2024 · Learn how code refactoring helps keep your code maintained at a lower cost as well as decrease technical debt. Sep 16, 2011 · Simon Thompson and Huiqing Li explain refactoring with functional languages and Wrangler (Erlang) and HaRe (Haskell). Abstract. Also: how Wrangler's ad-hoc mode allows everyone to write custom refactorings. Refactoring Functional Programs In Varmo Vene and Tarmo Uustalu, editors, Advanced Functional Programming, 5th International School, AFP 2004, volume 3622 of Lecture Notes in Computer Science, pages 182-196. Jan 15, 2025 · Migrating COBOL to modern languages like Java, Python, or C# is a common refactoring approach. These minor changes aim to make code more readable and maintainable. Large Language Models (LLMs) aim to generate and understand human-like text by leveraging deep learning and natural language processing techniques. Refactoring support for other programming languages is enabled through VS Code extensions that contribute language services. To mitigate this, we demonstrate the application of using a large language model (LLM), GPT-3. This book describes various refactoring techniques with a clear explanation of working on these refactoring process. Haskell (Marlow, 2010) is a lazy, strongly typed, purely functional language featuring higher-order functions, polymorphism, overloading via type classes and monadic effects. Abstract A functional aspect is an aspect that has the semantics of a trans-formation; it is a function that maps a program to an advised pro-gram. Functional Programming Patterns are a toolkit of solutions to common problems in software design. The core of the paper then outlines the main challenges that arise from our aim to produce practical tools for a decidedly non-toy language, summarizes our experience in trying to establish the necessary meta-programming infrastructure and gives Nov 27, 2019 · Discover this emerging programming language designed to build distributed systems with a completely new approach! Jun 6, 2024 · When it comes to working with programming languages for the first time, there’s a few milestones that students will achieve as they’re… Unlock the power of code refactoring in software development. Jul 12, 2025 · Java is a functional style language and the language like Haskell is a purely functional programming language. May 28, 2025 · Code refactoring is an important process in software development that involves restructuring code without changing its functional behavior. Refactoring, Second Edition, features an updated catalog of refactorings and includes JavaScript code examples, as well as new functional examples that demonstrate refactoring without classes. External links Some of the work being done in functional languages, and Haskell in particular: Refactoring is the process of improving the design of existing programs without changing their functionality. Let's understand a few concepts in functional programming: Higher-order functions: In functional programming, functions are to be considered as first-class citizens. Refactoring might be a useful tool in getting people to adopt functional languages in . Its fully possible to do functional programming in an object oriented platform like the JVM. Dec 22, 2024 · Refactoring is often the best approach when: Code is working but messy: If the code functions correctly but is hard to read or maintain, refactoring can make it cleaner and more understandable. Using 9 open-source projects, we have applied these two refactorings 1263 and 1709 times, respectively. May 5, 2024 · At some point in the world of software development, you will face the decision of whether to refactor your code or rewrite it entirely. - Forward Pathway Aug 14, 2004 · The functional programming group at Kent University, Canterbury, UK is developing the Haskell refactoring tool HaRe in the context of their Refactoring Functional Programs project [TR03, LRT03]. Our paper centres on the case study of refactoring a 400 line Haskell program written by one of our students. Refactoring is like putting things in order at your workplace. Aug 28, 2003 · We briefly introduce the ideas behind refactoring, and a set of elementary functional refactorings. fc4r w7gi85 rh0 6me9f zn thfid ivo fcrr jpn9s ctyvwu