--- title: Functional Optics for Modern Java | daily.dev description: Building an expression language interpreter using Java 25's sealed interfaces, records, and pattern matching combined with functional optics from... canonical: https://daily.dev/posts/functional-optics-for-modern-java-su7lt15ab twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Functional Optics for Modern Java | daily.dev og:description: Building an expression language interpreter using Java 25's sealed interfaces, records, and pattern matching combined with functional optics from... og:url: https://daily.dev/posts/functional-optics-for-modern-java-su7lt15ab og:image: https://api.daily.dev/og/posts/su7Lt15Ab.png og:image:alt: Functional Optics for Modern Java og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Functional Optics for Modern Java **[Scott Logic](https://daily.dev/sources/scottlogic)** · 19 min read · 0 upvotes · 0 comments ## Summary Building an expression language interpreter using Java 25's sealed interfaces, records, and pattern matching combined with functional optics from Higher-Kinded-J. The article demonstrates how to design an immutable Abstract Syntax Tree (AST) for parsing and evaluating expressions, generate lenses and prisms for type-safe navigation, and implement optimizations like constant folding and identity simplification. Optics provide composable, bidirectional transformations that eliminate manual reconstruction boilerplate while maintaining data-oriented programming principles. The Focus DSL enables fluent navigation through nested structures, making complex tree transformations readable and maintainable. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Lenses · Accessors.jl](https://daily.dev/posts/lenses-accessors-jl-gm3vcv4di) · Hacker News · 0 upvotes · 0 comments - [Extreme Haskell: Typed Expression EDSLs \(Part 1\)](https://daily.dev/posts/extreme-haskell-typed-expression-edsls-part-1--dstmoi7xv) · Planet Haskell · 0 upvotes · 0 comments - [Functional Programming in Kotlin](https://daily.dev/posts/functional-programming-in-kotlin-qtcdwbyul) · SoftwareMill · 0 upvotes · 0 comments - [Issue 510](https://daily.dev/posts/issue-510-ybgjvjsmv) · Haskell Weekly · 0 upvotes · 0 comments - [Clojure for Java developers: What you need to know](https://daily.dev/posts/clojure-for-java-developers-what-you-need-to-know-s4f5memil) · InfoWorld · 1 upvotes · 0 comments --- Tags: [#java](https://daily.dev/tags/java), [#functional-programming](https://daily.dev/tags/functional-programming), [#compiler](https://daily.dev/tags/compiler) [View this post on daily.dev](https://daily.dev/posts/functional-optics-for-modern-java-su7lt15ab) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Functional Optics for Modern Java","url":"https://daily.dev/posts/functional-optics-for-modern-java-su7lt15ab","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/functional-optics-for-modern-java-su7lt15ab"},"datePublished":"2026-01-23T13:58:08.605Z","dateModified":"2026-01-23T13:58:30.625Z","description":"Building an expression language interpreter using Java 25's sealed interfaces, records, and pattern matching combined with functional optics from...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/a204547377e3fa7e5addafc3ed4f8601?_a=AQAEulh","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/a204547377e3fa7e5addafc3ed4f8601?_a=AQAEulh","isAccessibleForFree":true,"articleSection":"Scott Logic","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Scott Logic","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/65c5cc47d7674fbc83d00599d7b44552","url":"https://daily.dev/sources/scottlogic"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/functional-optics-for-modern-java-su7lt15ab","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"java,functional-programming,compiler","timeRequired":"PT19M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Scott Logic","item":"https://daily.dev/sources/scottlogic"},{"@type":"ListItem","position":3,"name":"Functional Optics for Modern Java"}]} ```