qr

qr

qr is a fast, native QR code generator library for EZ. It operates seamlessly by wrapping the C libqrencode library through EZ's native Foreign Function Interface (FFI).

Requirements

You must have the qrencode library installed on your system.
On Windows with MSYS2, run:

pacman -S mingw-w64-x86_64-qrencode

Quick Start

use "qr" as qrlib

# Create a QR code from text
# The second parameter is Error Correction Level:
# 0 = L, 1 = M, 2 = Q, 3 = H
qr = qrlib.QRCode("https://github.com/ez-lang/ez", 0)

# Render it directly to the terminal!
out qr.toAscii()

API Reference

model QRCode

init(text, errorLevel)

Constructs a new QRCode containing the specified data.

• text (string): The data/text to encode into the QR code.
• errorLevel (integer, optional): The error correction level.
• 0: Low (approx 7%)
• 1: Medium (approx 15%)
• 2: Quartile (approx 25%)
• 3: High (approx 30%)

If errorLevel is omitted, it defaults to 0.

toMatrix()

Extracts the raw 2D array representation of the QR code.

• Returns: A 2D array (list of lists) of booleans. true means a black module, false means a white module. The array has dimensions width × width.

toAscii()

Generates an optimized string representation of the QR code for terminal output using UTF-8 half-block characters.

• Returns: A string containing the printable QR code, padded with a 2-module quiet zone border.

saveImage(filepath, scale)

Saves the generated QR code to disk as a high-quality, uncompressed 24-bit Bitmap (BMP) image. It uses FFI to write the binary file entirely natively without requiring any external image processing libraries.

• filepath (string): The destination path (e.g., "output.bmp").
• scale (integer, optional): The scaling factor (pixels per QR module). Defaults to 10. A standard QR code (version 1) has 21x21 modules, so a scale of 10 results in a 290x290 pixel image (including a 4-module quiet zone border).
• Returns: true if successful, throws an error if file access fails.