A pure-Scala, dependency-free QR Code generator, cross-published for the JVM, JavaScript (Scala.js), and Native (Scala Native).

It is a faithful port of Project Nayuki's QR Code generator library (MIT), which makes it a well-tested reference for the parts that are easy to get wrong: Reed–Solomon error correction over GF(2⁸), data masking with the four penalty rules, and version/character-count selection.

• All 40 versions (21×21 up to 177×177 modules) and all four error-correction levels (L / M / Q / H).
• Automatic mode selection (numeric / alphanumeric / byte), automatic version selection, automatic optimal masking, and optional error-correction boosting.
• Zero runtime dependencies; the core is pure Scala with no java.* or platform APIs, so it runs identically on JVM, JS, and Native.
• A raw boolean module matrix (draw it however you like) plus a self-contained toSvg convenience.

import io.github.edadma.qr.*

val qr = Qr.encode("https://example.com", Ecc.Quartile)

// Read the module grid directly (true = dark):
for y <- 0 until qr.size do
  println((0 until qr.size).map(x => if qr(x, y) then "██" else "  ").mkString)

// Or emit an SVG string:
val svg: String = qr.toSvg(scale = 8, border = 4, dark = "#000000", light = "#ffffff")

For finer control — a fixed version range, an explicit mask, raw bytes, or pre-built segments — use the factory methods on QrCode:

QrCode.encodeText("HELLO", Ecc.High, minVersion = 1, maxVersion = 10)
QrCode.encodeBinary(bytes, Ecc.Medium)
QrCode.encodeSegments(QrSegment.makeSegments("12345"), Ecc.Low)

• Qr.encode(text, ecc = Ecc.Medium): QrCode — the common entry point.
• QrCode — size: Int, version: Int, mask: Int, module(x, y): Boolean / apply(x, y), toSvg(scale, border, dark, light): String.
• Ecc — Low, Medium, Quartile, High.
• QrSegment — makeSegments, makeNumeric, makeAlphanumeric, makeBytes for building segment lists by hand.

sbt qrJVM/test      # JVM
sbt qrJS/test       # JavaScript (Node.js)
sbt qrNative/test   # Native (LLVM/Clang)

MIT — see LICENSE. This library is a derivative of Project Nayuki's MIT-licensed QR Code generator library; his copyright notice is retained in the license file.