Pippa

A terminal UI framework for MoonBit, inspired by bubbletea (Go) and the Elm Architecture.

Overview

Pippa provides a Model–Update–View pattern where:

• Model — application state is a plain struct.
• Msg — updates are driven by typed messages (key presses, resize, timers, custom events).
• View — the view function renders state to a string of ANSI-formatted output.

The runtime handles raw terminal mode, input parsing, and efficient diffing and re-rendering, so library users only think about state transitions and string output.

A component library ships alongside the core — spinners, text inputs, textareas, lists, selection lists, tables, paginators, viewports, timers, stopwatches, file pickers, and animated progress bars — each implemented as composable Models that can be embedded in larger applications.

A richer styling package is also included for layout and visual styling: hex/RGB colors, borders, padding, margins, joins, placement, and higher-level composition primitives.

Quick Start

moon test
moon run src/examples/showcase

The showcase example exercises the runtime, components, styling, spring animation, focus handling, and viewport behavior.

Project Structure

src/                          # Source root (moon.mod.json → source: "src")
├── moon.pkg                  # Core library package
├── types.mbt                 # Cmd, UpdateResult, WindowSize, Program
├── message.mbt               # KeyMsg, MouseMsg, InputEvent
├── command.mbt               # Command helpers and composition
├── program.mbt               # Program[Model, Msg] entry point
├── ansi.mbt                  # ANSI escape sequence helpers
├── component/                # Composable component sub-package
│   ├── moon.pkg
│   └── ...                   # Spinner, textarea, viewport, progress, etc.
├── styling/                  # Higher-level styling and layout package
│   ├── moon.pkg
│   └── styling.mbt
└── examples/
    ├── hello/                # Minimal example app
    └── showcase/             # Rich interactive demo

Development

moon check          # Type-check the project
moon fmt            # Format all source files
moon info           # Refresh generated package interfaces
moon test           # Run all tests
moon test --update  # Run tests and update snapshots
moon run src/examples/hello  # Run the hello example
moon run src/examples/showcase  # Run the showcase demo

License

Apache-2.0