Tweaked comments and statement order in QrCode constructor, in most languages.

cpp/QrCode.cpp

@@ -115,16 +115,14 @@ QrCode QrCode::encodeSegments(const vector<QrSegment> &segs, Ecc ecl,
 
 
 QrCode::QrCode(int ver, Ecc ecl, const vector<uint8_t> &dataCodewords, int mask) :
-		// Initialize fields
+		// Initialize fields and check arguments
 		version(ver),
-		size(MIN_VERSION <= ver && ver <= MAX_VERSION ? ver * 4 + 17 : -1),  // Avoid signed overflow undefined behavior
 		errorCorrectionLevel(ecl),
 		modules   (size, vector<bool>(size)),  // Initially all white
 		isFunction(size, vector<bool>(size)) {
-	
-	// Check arguments
 	if (ver < MIN_VERSION || ver > MAX_VERSION || mask < -1 || mask > 7)
 		throw std::domain_error("Value out of range");
+	size = ver * 4 + 17;
 	
 	// Compute ECC, draw modules, do masking
 	drawFunctionPatterns();

java/io/nayuki/qrcodegen/QrCode.java

@@ -213,15 +213,13 @@ public final class QrCode {
 	 * or if the data is the wrong length for the specified version and error correction level
 	 */
 	public QrCode(int ver, Ecc ecl, byte[] dataCodewords, int mask) {
-		// Check arguments
+		// Check arguments and initialize fields
-		errorCorrectionLevel = Objects.requireNonNull(ecl);
-		Objects.requireNonNull(dataCodewords);
 		if (ver < MIN_VERSION || ver > MAX_VERSION || mask < -1 || mask > 7)
 			throw new IllegalArgumentException("Value out of range");
-		
-		// Initialize fields
 		version = ver;
 		size = ver * 4 + 17;
+		errorCorrectionLevel = Objects.requireNonNull(ecl);
+		Objects.requireNonNull(dataCodewords);
 		modules    = new boolean[size][size];  // Initially all white
 		isFunction = new boolean[size][size];
 		

javascript/qrcodegen.js

@@ -72,11 +72,11 @@ var qrcodegen = new function() {
 		
 		/*---- Constructor (low level) ----*/
 		
-		// Check arguments and handle simple scalar fields
+		// Check scalar arguments
-		if (mask < -1 || mask > 7)
-			throw "Mask value out of range";
 		if (version < MIN_VERSION || version > MAX_VERSION)
 			throw "Version value out of range";
+		if (mask < -1 || mask > 7)
+			throw "Mask value out of range";
 		var size = version * 4 + 17;
 		
 		// Initialize both grids to be size*size arrays of Boolean false

python/qrcodegen.py

@@ -151,21 +151,21 @@ class QrCode(object):
 		and mask number. mask = -1 is for automatic choice, or 0 to 7 for fixed choice. This is a cumbersome low-level constructor
 		that should not be invoked directly by the user. To go one level up, see the QrCode.encode_segments() function."""
 		
-		# Check arguments and handle simple scalar fields
+		# Check scalar arguments and set fields
-		if not (-1 <= mask <= 7):
-			raise ValueError("Mask value out of range")
 		if not (QrCode.MIN_VERSION <= version <= QrCode.MAX_VERSION):
 			raise ValueError("Version value out of range")
+		if not (-1 <= mask <= 7):
+			raise ValueError("Mask value out of range")
 		if not isinstance(errcorlvl, QrCode.Ecc):
 			raise TypeError("QrCode.Ecc expected")
 		self._version = version
-		self._errcorlvl = errcorlvl
 		self._size = version * 4 + 17
+		self._errcorlvl = errcorlvl
 		
 		if len(datacodewords) != QrCode._get_num_data_codewords(version, errcorlvl):
 			raise ValueError("Invalid array length")
 		
-		# Initialize grids of modules
+		# Initialize both grids to be size*size arrays of Boolean false
 		# The modules of this QR Code symbol (False = white, True = black). Immutable after constructor finishes
 		self._modules    = [[False] * self._size for _ in range(self._size)]  # Initially all white
 		# Indicates function modules that are not subjected to masking. Discarded when constructor finishes

typescript/qrcodegen.ts

@@ -160,11 +160,11 @@ namespace qrcodegen {
 				// (mask = -1), the resulting object will still have a mask value between 0 and 7.
 				public readonly mask: int) {
 			
-			// Check arguments and handle simple scalar fields
+			// Check scalar arguments
-			if (mask < -1 || mask > 7)
-				throw "Mask value out of range";
 			if (version < QrCode.MIN_VERSION || version > QrCode.MAX_VERSION)
 				throw "Version value out of range";
+			if (mask < -1 || mask > 7)
+				throw "Mask value out of range";
 			this.size = version * 4 + 17;
 			
 			// Initialize both grids to be size*size arrays of Boolean false