--- title: "Bluefin" url: https://daily.dev/posts/bluefin-rwvrch0oa source_url: https://hackage.haskell.org/package/bluefin-0.0.4.3/docs/Bluefin.html type: article source: "Lobsters" published: 2024-04-26T01:26:16.206Z updated: 2024-05-09T09:27:15.675Z tags: ["haskell"] reading_time: 6 upvotes: 0 comments: 0 language: 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. # Bluefin **[Lobsters](https://daily.dev/sources/lobsters)** · 6 min read · 0 upvotes · 0 comments ## Summary Bluefin is a Haskell effect system that allows you to mix a variety of effects, such as early return, exceptions, I/O, mutable state, and streams. Effects are accessed through value-level handles, and Bluefin supports multiple effects of the same type. Exceptions in Bluefin are always handled and cannot escape the scope of their handler. Bluefin functions have a common type signature pattern, and the implementation style is similar to effectful. Tips for using Bluefin include using certain language extensions and writing explicit type signatures for handlers. Bluefin allows you to create your own effects, and an example is provided for counting positives and negatives using Bluefin. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Don’t just attend KubeCon \+ CloudNativeCon, Merge Forward your experience\!](https://daily.dev/posts/don-t-just-attend-kubecon-cloudnativecon-merge-forward-your-experience--l0rpp73x8) · CNCF · 0 upvotes · 0 comments - [Announcing H2 2026 KCDs](https://daily.dev/posts/announcing-h2-2026-kcds-m96goajm1) · CNCF · 1 upvotes · 0 comments - [Two months of Open Community Groups](https://daily.dev/posts/two-months-of-open-community-groups-asf52zhbs) · CNCF · 0 upvotes · 0 comments - [CNCF Unveils Schedule for KubeCon \+ CloudNativeCon Europe 2026](https://daily.dev/posts/cncf-unveils-schedule-for-kubecon-cloudnativecon-europe-2026-ikhcoa5cb) · CNCF · 2 upvotes · 0 comments - [CNCF Debuts KubeCon \+ CloudNativeCon Japan 2026 Schedule](https://daily.dev/posts/cncf-debuts-kubecon-cloudnativecon-japan-2026-schedule-xp5pyudub) · CNCF · 1 upvotes · 0 comments --- Tags: [#haskell](https://daily.dev/tags/haskell) [View this post on daily.dev](https://daily.dev/posts/bluefin-rwvrch0oa)