#qrc — QR code encoder for MoonBit

#Features

• ✅ QR code encoding with multiple data modes (numeric, alphanumeric, byte)
• ✅ Automatic mode detection
• ✅ Multiple output formats: SVG, ANSI terminal, plain text, compact text
• ✅ Reed-Solomon error correction with Galois Field arithmetic
• ✅ No external dependencies
• ✅ WebAssembly compatible
• ⚠️ Kanji mode (treated as byte mode)

#Installation

moon install bobzhang/qrc

#Usage

#Basic Usage

///|
test {
  // Generate a QR code with default settings
  let qr = @bobzhang/qrc.encode("Hello, MoonBit!")

  // Print QR code information
  println(@bobzhang/qrc/render.info(qr))

  // Render as text
  println(@bobzhang/qrc/render.to_text(qr))

  // Render as compact text (using Unicode block characters)
  println(@bobzhang/qrc/render.to_compact_text(qr))

  // Render as SVG
  let svg = @bobzhang/qrc/render.to_svg(qr)
  println(svg)

  // Render as ANSI terminal output (with colors)
  println(@bobzhang/qrc/render.to_ansi(qr))
}

#Advanced Usage

///|
test {
  // Generate QR code with specific error correction level
  let qr = @qrc.encode_with_ec("Important data", H)

  // Manual mode detection
  let mode = @qrc.detect_mode("12345") // Returns Mode::Numeric
  let mode2 = @qrc.detect_mode("HELLO WORLD") // Returns Mode::Alphanumeric
  let mode3 = @qrc.detect_mode("Hello, World!")
  // Returns Mode::Byte
}

#Data Modes

• Numeric: Only digits 0-9 (most efficient for numbers)
• Alphanumeric: Digits, uppercase letters A-Z, and symbols $%*+-./:
• Byte: Any data (UTF-8 encoded)
• Kanji: Japanese characters (currently treated as byte mode)

#Error Correction Levels

• L: ~7% correction capability
• M: ~15% correction capability (default)
• Q: ~25% correction capability
• H: ~30% correction capability

#Example Output

QR Code Information:
Version: 1
Size: 21x21
Mode: Byte
Error Correction: M (~15%)
Data: "Hello, MoonBit!"

Text representation:
██████████████  ████  ██████████████
██          ██  ████  ██          ██
██  ██████  ██  ████  ██  ██████  ██
██  ██████  ██  ████  ██  ██████  ██
██  ██████  ██  ████  ██  ██████  ██
██          ██  ████  ██          ██
██████████████  ████  ██████████████
                ████                
████████████████████████████████████
...

#API Reference

#Core Functions

• encode(data: String) -> QRCode - Generate QR code with default error correction
• encode_with_ec(data: String, ec: ErrorCorrectionLevel) -> QRCode - Generate QR code with specific error correction
• detect_mode(data: String) -> Mode - Detect the best encoding mode for data

#Rendering Functions

• @render.to_text(qr: QRCode) -> String - Plain text representation
• @render.to_compact_text(qr: QRCode) -> String - Compact Unicode representation
• @render.to_svg(qr: QRCode) -> String - SVG format
• @render.to_ansi(qr: QRCode) -> String - ANSI terminal with colors
• @render.info(qr: QRCode) -> String - QR code information

#Running the Example

# Clone the repository
git clone <repository-url>
cd qrc

# Run tests
moon test

# Run the example
moon run src

#Limitations

• ✅ Full Reed-Solomon error correction with proper Galois Field arithmetic
• ✅ Supports all error correction levels (L, M, Q, H)
• ✅ Proper data formatting with mode indicators and padding
• ✅ QR version 1 (21x21 modules) with finder patterns and timing patterns
• ⚠️ Kanji mode is treated as byte mode
• ⚠️ No format information or version information encoding
• ⚠️ No masking patterns applied

• Complete GF(256) Galois Field arithmetic
• Generator polynomial computation
• Proper error correction codeword generation
• Data capacity management for different error correction levels

#Contributing

#License

#Acknowledgments

• Original OCaml qrc library by Daniel Bünzli
• MoonBit language team for the excellent tooling and documentation