# layoutz **Simple, beautiful CLI output for Haskell 🪶** Build declarative and composable sections, trees, tables, dashboards for your Haskell applications. ## Features - Zero dependencies, use `Layoutz.hs` like a header file - Rich text formatting: alignment, underlines, padding, margins - Lists, trees, tables, charts, banners... ## Installation Add to your `package.yaml` or `.cabal` file: ```yaml dependencies: - layoutz ``` Or install directly: ```bash cabal install layoutz ``` All you need: ```haskell import Layoutz ``` ## Quickstart Beautiful, compositional text layouts: ```haskell import Layoutz demo = layout [ center $ row [text "Layoutz", underline' "ˆ" $ text "DEMO"] , br , row [ statusCard "Users" "1.2K" , statusCard' DoubleBorder "API" "UP" , statusCard' ThickBorder "CPU" "23%" , table' RoundBorder ["Name", "Role", "Status"] [ [text "Alice", text "Engineer", text "Online"] , [text "Eve", text "QA", text "Away"] ] , section "Pugilists" [kv [("Kazushi", "Sakuraba"), ("Jet", "Li")]] ] ] putStrLn $ render demo ``` ``` Layoutz DEMO ˆˆˆˆ ┌─────────┐ ╔═══════╗ ┏━━━━━━━┓ ╭───────┬──────────┬────────╮ === Pugilists === │ Users │ ║ API ║ ┃ CPU ┃ │ Name │ Role │ Status │ Kazushi: Sakuraba │ 1.2K │ ║ UP ║ ┃ 23% ┃ ├───────┼──────────┼────────┤ Jet: Li └─────────┘ ╚═══════╝ ┗━━━━━━━┛ │ Alice │ Engineer │ Online │ │ Eve │ QA │ Away │ ╰───────┴──────────┴────────╯ ``` ## Core concepts - Every piece of content is an `Element` - Elements are **immutable** and **composable** - build complex layouts by combining simple elements - A `layout` arranges elements **vertically**: ```haskell layout [elem1, elem2, elem3] -- Joins with "\n" ``` Call `render` on any element to get a string The power comes from **uniform composition** - since everything has the `Element` typeclass, everything can be combined. ## Elements ### Text ```haskell text "Simple text" ``` ``` Simple text ``` ### Line Break Add line breaks with `br`: ```haskell layout [text "Line 1", br, text "Line 2"] ``` ``` Line 1 Line 2 ``` ### Section: `section` ```haskell section "Config" [kv [("env", "prod")]] section' "-" "Status" [kv [("health", "ok")]] section'' "#" "Report" 5 [kv [("items", "42")]] ``` ``` === Config === env: prod --- Status --- health: ok ##### Report ##### items: 42 ``` ### Layout (vertical): `layout` ```haskell layout [text "First", text "Second", text "Third"] ``` ``` First Second Third ``` ### Row (horizontal): `row` ```haskell row [text "Left", text "Middle", text "Right"] ``` ``` Left Middle Right ``` ### Horizontal rule: `hr` ```haskell hr hr' "~" hr'' "-" 10 ``` ``` ────────────────────────────────────────────────── ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ---------- ``` ### Key-value pairs: `kv` ```haskell kv [("name", "Alice"), ("role", "admin")] ``` ``` name: Alice role: admin ``` ### Table: `table` Tables automatically handle alignment and borders: ```haskell table ["Name", "Age", "City"] [ [text "Alice", text "30", text "New York"] , [text "Bob", text "25", text ""] -- Missing values handled , [text "Charlie", text "35", text "London"] ] ``` ``` ┌─────────┬─────┬─────────┐ │ Name │ Age │ City │ ├─────────┼─────┼─────────┤ │ Alice │ 30 │ New York│ │ Bob │ 25 │ │ │ Charlie │ 35 │ London │ └─────────┴─────┴─────────┘ ``` ### Unordered Lists: `ul` Clean unordered lists with automatic nesting: ```haskell ul [text "Feature A", text "Feature B", text "Feature C"] ``` ``` • Feature A • Feature B • Feature C ``` Nested lists with auto-styling: ```haskell ul [ text "Backend" , ul [text "API", text "Database"] , text "Frontend" , ul [text "Components", ul [text "Header", ul [text "Footer"]]] ] ``` ``` • Backend ◦ API ◦ Database • Frontend ◦ Components ▪ Header • Footer ``` ### Underline: `underline` Add underlines to any element: ```haskell underline $ text "Important Title" underline' "=" $ text "Custom" ``` ``` Important Title ─────────────── Custom ══════ ``` ### Box: `box` With title: ```haskell box "Summary" [kv [("total", "42")]] ``` ``` ┌──Summary───┐ │ total: 42 │ └────────────┘ ``` Without title: ```haskell box "" [kv [("total", "42")]] ``` ``` ┌────────────┐ │ total: 42 │ └────────────┘ ``` ### Status card: `statusCard` ```haskell statusCard "CPU" "45%" ``` ``` ┌───────┐ │ CPU │ │ 45% │ └───────┘ ``` ### Progress bar: `inlineBar` ```haskell inlineBar "Download" 0.75 ``` ``` Download [███████████████─────] 75% ``` ### Tree: `tree` ```haskell tree "Project" [ branch "src" [ leaf "main.hs" , leaf "test.hs" ] , branch "docs" [ leaf "README.md" ] ] ``` ``` Project ├── src │ ├── main.hs │ └── test.hs └── docs └── README.md ``` ### Chart: `chart` ```haskell chart [("Web", 10), ("Mobile", 20), ("API", 15)] ``` ``` Web │████████████████████ 10 Mobile │████████████████████████████████████████ 20 API │██████████████████████████████ 15 ``` ### Padding: `pad` Add uniform padding around any element: ```haskell pad 2 $ text "content" ``` ``` content ``` ### Centering: `center` Smart auto-centering and manual width: ```haskell center $ text "Auto-centered" -- Uses layout context center' 20 $ text "Manual width" -- Fixed width ``` ``` Auto-centered Manual width ``` ### Margin: `margin` Use `margin` for colorful "compiler-style" prefixes: ```haskell layout [ marginError [text "Type error: expected Int, got String"] , marginWarn [text "Unused variable 'temp'"] , marginSuccess [text "Build completed successfully"] , marginInfo [text "Pro tip: Use layoutz for beautiful output"] ] ``` ``` [error] Type error: expected Int, got String [warn] Unused variable 'temp' [success] Build completed successfully [info] Pro tip: Use layoutz for beautiful output ``` ## Border Styles Elements like `box`, `table`, and `statusCard` support different border styles: **NormalBorder** (default): ```haskell box "Title" [text "content"] ``` ``` ┌──Title──┐ │ content │ └─────────┘ ``` **DoubleBorder**: ```haskell statusCard' DoubleBorder "API" "UP" ``` ``` ╔═══════╗ ║ API ║ ║ UP ║ ╚═══════╝ ``` **ThickBorder**: ```haskell table' ThickBorder ["Name"] [[text "Alice"]] ``` ``` ┏━━━━━━━┓ ┃ Name ┃ ┣━━━━━━━┫ ┃ Alice ┃ ┗━━━━━━━┛ ``` **RoundBorder**: ```haskell box' RoundBorder "Info" [text "content"] ``` ``` ╭──Info───╮ │ content │ ╰─────────╯ ``` ## REPL Usage Drop into GHCi to experiment: ```bash cabal repl ``` ```haskell λ> import Layoutz λ> putStrLn $ render $ center $ box "Hello" [text "World!"] ┌──Hello──┐ │ World! │ └─────────┘ λ> putStrLn $ render $ table ["A", "B"] [[text "1", text "2"]] ┌───┬───┐ │ A │ B │ ├───┼───┤ │ 1 │ 2 │ └───┴───┘ ``` ## Inspiration - Original Scala [layoutz](https://github.com/mattlianje/layoutz)