--- title: Extreme Haskell: Typed Expression EDSLs (Part 1) | daily.dev description: A deep dive into building a fully type-safe embedded domain-specific language (EDSL) in Haskell that represents a typed lambda calculus. Starting from an... canonical: https://daily.dev/posts/extreme-haskell-typed-expression-edsls-part-1--dstmoi7xv twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Extreme Haskell: Typed Expression EDSLs (Part 1) | daily.dev og:description: A deep dive into building a fully type-safe embedded domain-specific language (EDSL) in Haskell that represents a typed lambda calculus. Starting from an... og:url: https://daily.dev/posts/extreme-haskell-typed-expression-edsls-part-1--dstmoi7xv og:image: https://api.daily.dev/og/posts/dSTmoI7XV.png og:image:alt: Extreme Haskell: Typed Expression EDSLs (Part 1) 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. # Extreme Haskell: Typed Expression EDSLs (Part 1) **[Planet Haskell](https://daily.dev/sources/phaskell)** · 23 min read · 0 upvotes · 0 comments ## Summary A deep dive into building a fully type-safe embedded domain-specific language (EDSL) in Haskell that represents a typed lambda calculus. Starting from an untyped expression ADT, the post progressively adds phantom type indices, singletons, existentials, runtime type equality, typed records and sums using vinyl-style heterogeneous lists, and finally a scoped variable environment that makes ill-typed or unbound variable references impossible to construct in Haskell. The result is an expression language where GHC statically rejects any invalid domain-level term. The series aims to eventually compile these typed expressions to multiple backends (C, JavaScript) and generate Graphviz visualizations of state machines. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Dependent types in Haskell, Part 3](https://daily.dev/posts/dependent-types-in-haskell-part-3-dre5drhgl) · Serokell · 0 upvotes · 0 comments - ["Five-Point Haskell": Total Depravity \(and Defensive Typing\)](https://daily.dev/posts/five-point-haskell-total-depravity-and-defensive-typing--xwwoyitrt) · Planet Haskell · 0 upvotes · 0 comments - [Enterprise Haskell at H-E-B](https://daily.dev/posts/enterprise-haskell-at-h-e-b-sjpe3tn1b) · Lobsters · 0 upvotes · 0 comments - [Elixir v1.20 released: now a gradually typed language](https://daily.dev/posts/elixir-v1-20-released-now-a-gradually-typed-language-081x31cuq) · Elixir · 4 upvotes · 0 comments - [Issue 496](https://daily.dev/posts/issue-496-pv6ethck7) · Haskell Weekly · 0 upvotes · 0 comments --- Tags: [#haskell](https://daily.dev/tags/haskell) [View this post on daily.dev](https://daily.dev/posts/extreme-haskell-typed-expression-edsls-part-1--dstmoi7xv) ```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":"Extreme Haskell: Typed Expression EDSLs (Part 1)","url":"https://daily.dev/posts/extreme-haskell-typed-expression-edsls-part-1--dstmoi7xv","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/extreme-haskell-typed-expression-edsls-part-1--dstmoi7xv"},"datePublished":"2026-07-07T19:36:50.501Z","dateModified":"2026-07-07T19:37:18.530Z","description":"A deep dive into building a fully type-safe embedded domain-specific language (EDSL) in Haskell that represents a typed lambda calculus. 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