Kryon

Multi-language UI framework - Write declarative UI once, deploy to Web, Desktop, Mobile, and more.

Quick Start

# Build
make && make install

# Run examples (transpile KRY to another language)
kryon run --target=limbo+tk@taiji examples/kry/hello_world.kry
kryon run --target=tcl+tk@desktop examples/kry/hello_world.kry

Targets

Kryon transpiles KRY source code to other languages using language+toolkit@platform format:

Target	Language	Toolkit	Platform	Status
tcl+tk@desktop	Tcl	Tk	Desktop	🟡 Limited (30%)
javascript+dom@web	JavaScript	DOM	Web	🟡 Limited (60%)
limbo+tk@taiji	Limbo	Tk	TaijiOS	🔴 Not Implemented
c+sdl3@desktop	C	SDL3	Desktop	🔴 In Progress
c+raylib@desktop	C	Raylib	Desktop	🔴 In Progress
kotlin+android@mobile	Kotlin	Android	Mobile	🔴 Not Implemented

KRY is the source language - all .kry files are transpiled to target languages.

Actually Working:

• ✅ Terminal apps (all languages with terminal toolkit)
• 🟡 Tcl/Tk (loses script code on round-trip)
• 🟡 Web/DOM (loses some presentation details)

Legend:

• 🟢 Production Ready - Fully working for production use
• 🟡 Limited - Works but has limitations or bugs
• 🔴 Not Implemented - Planned but not yet built

Platform Aliases

Shorter aliases are available for convenience:

• taiji → taijios
• inferno → taijios

Auto-Resolution

If a language has only one valid platform+toolkit combination, you can omit them:

# JavaScript only works with DOM on web
kryon run --target=javascript main.kry  # Auto-resolves to javascript+dom@web

If a language has multiple valid combinations, you must specify explicitly:

# C works with multiple toolkits/platforms
kryon run --target=c+sdl3@desktop main.kry  # Must specify

Examples

KRY source files (.kry) are transpiled to target languages:

# TaijiOS (using alias)
kryon run --target=limbo+tk@taiji main.kry

# Desktop
kryon run --target=c+sdl3@desktop main.kry

# Web (auto-resolves)
kryon run --target=javascript main.kry

# Mobile
kryon run --target=kotlin+android@mobile main.kry

Commands

# List all valid language+toolkit@platform combinations
kryon targets

# Show languages, toolkits, or platforms
kryon lang                              # List all languages
kryon toolkit                           # List all toolkits
kryon platform                          # List all platforms

# Show capabilities
kryon capabilities                      # Show all combinations
kryon capabilities --lang=c            # Show toolkits for C
kryon capabilities --toolkit=sdl3      # Show languages for SDL3

# Build and run
kryon build --target=limbo+tk@taiji main.kry
kryon run --target=limbo+tk@taiji main.kry

# Dev server with hot reload (web only)
kryon dev main.kry

Directory Structure

kryon/
├── ir/              # Intermediate Representation
├── codegens/        # Code generators
│   ├── languages/   # Language emitters
│   ├── toolkits/    # Toolkit profiles
│   └── platforms/   # Platform profiles
├── cli/             # Command-line interface
├── runtime/         # Runtime libraries
├── tests/           # Test suites
└── examples/        # Example code

See ARCHITECTURE.md for detailed architecture.

Round-Trip Testing

Test that codegens preserve information through KRY → KIR → Target → KIR → KRY:

# Run test suite
bash tests/round_trip/test_roundtrip.sh

# Manual test
kryon parse hello_world.kry -o step1.kir
kryon codegen kry step1.kir step2_kry/
kryon parse step2_kry/main.kry -o step3.kir
kryon codegen kry step3.kir step4_kry/
diff hello_world.kry step4_kry/main.kry

Results:

• ✅ KRY → KRY: 95%+ preservation (production ready)
• 🟡 Tcl+Tk: ~30% preservation (scripts lost, expected)
• 🟡 JavaScript+DOM: ~60% preservation (presentation layer)
• 🔴 C targets: Parser in testing phase

See CODEGEN_STATUS.md for detailed status and roadmap.

License

MIT