Simplified QrSegment.Mode.numCharCountBits() in all language versions.

c/qrcodegen.c

@@ -999,12 +999,7 @@ testable int getTotalBits(const struct qrcodegen_Segment segs[], size_t len, int
 // given mode at the given version number. The result is in the range [0, 16].
 static int numCharCountBits(enum qrcodegen_Mode mode, int version) {
 	assert(qrcodegen_VERSION_MIN <= version && version <= qrcodegen_VERSION_MAX);
-	int i;
+	int i = (version + 7) / 17;
-	if      ( 1 <= version && version <=  9)  i = 0;
-	else if (10 <= version && version <= 26)  i = 1;
-	else if (27 <= version && version <= 40)  i = 2;
-	else { assert(false);  return -1; }  // Dummy value
-	
 	switch (mode) {
 		case qrcodegen_Mode_NUMERIC     : { static const int temp[] = {10, 12, 14}; return temp[i]; }
 		case qrcodegen_Mode_ALPHANUMERIC: { static const int temp[] = { 9, 11, 13}; return temp[i]; }

cpp/QrSegment.cpp

@@ -47,10 +47,7 @@ int QrSegment::Mode::getModeBits() const {
 
 
 int QrSegment::Mode::numCharCountBits(int ver) const {
-	if      ( 1 <= ver && ver <=  9)  return numBitsCharCount[0];
+	return numBitsCharCount[(ver + 7) / 17];
-	else if (10 <= ver && ver <= 26)  return numBitsCharCount[1];
-	else if (27 <= ver && ver <= 40)  return numBitsCharCount[2];
-	else  throw std::domain_error("Version number out of range");
 }
 
 

java/io/nayuki/qrcodegen/QrSegment.java

@@ -270,10 +270,8 @@ public final class QrSegment {
 		 * @throws IllegalArgumentException if the version number is out of range
 		 */
 		int numCharCountBits(int ver) {
-			if      ( 1 <= ver && ver <=  9)  return numBitsCharCount[0];
+			assert QrCode.MIN_VERSION <= ver && ver <= QrCode.MAX_VERSION;
-			else if (10 <= ver && ver <= 26)  return numBitsCharCount[1];
+			return numBitsCharCount[(ver + 7) / 17];
-			else if (27 <= ver && ver <= 40)  return numBitsCharCount[2];
-			else  throw new IllegalArgumentException("Version number out of range");
 		}
 		
 	}

javascript/qrcodegen.js

@@ -861,10 +861,7 @@ var qrcodegen = new function() {
 		
 		// (Package-private) Returns the bit width of the segment character count field for this mode object at the given version number.
 		this.numCharCountBits = function(ver) {
-			if      ( 1 <= ver && ver <=  9)  return ccbits[0];
+			return ccbits[Math.floor((ver + 7) / 17)];
-			else if (10 <= ver && ver <= 26)  return ccbits[1];
-			else if (27 <= ver && ver <= 40)  return ccbits[2];
-			else  throw "Version number out of range";
 		};
 	}
 	

python/qrcodegen.py

@@ -740,10 +740,7 @@ class QrSegment(object):
 		# Package-private method
 		def num_char_count_bits(self, ver):
 			"""Returns the bit width of the segment character count field for this mode object at the given version number."""
-			if    1 <= ver <=  9:  return self._charcounts[0]
+			return self._charcounts[(ver + 7) // 17]
-			elif 10 <= ver <= 26:  return self._charcounts[1]
-			elif 27 <= ver <= 40:  return self._charcounts[2]
-			else:  raise ValueError("Version number out of range")
 	
 	# Public constants. Create them outside the class.
 	Mode.NUMERIC      = Mode(0x1, (10, 12, 14))

rust/src/lib.rs

@@ -1048,24 +1048,13 @@ impl QrSegmentMode {
 	// for this mode object at the given version number.
 	pub fn num_char_count_bits(&self, ver: Version) -> u8 {
 		use QrSegmentMode::*;
-		let array: [u8; 3] = match *self {
+		(match *self {
 			Numeric      => [10, 12, 14],
 			Alphanumeric => [ 9, 11, 13],
 			Byte         => [ 8, 16, 16],
 			Kanji        => [ 8, 10, 12],
 			Eci          => [ 0,  0,  0],
-		};
+		})[((ver.value() + 7) / 17) as usize]
-		
-		let ver = ver.value();
-		if 1 <= ver && ver <= 9 {
-			array[0]
-		} else if 10 <= ver && ver <= 26 {
-			array[1]
-		} else if 27 <= ver && ver <= 40 {
-			array[2]
-		} else {
-			panic!("Version number out of range");
-		}
 	}
 	
 }

typescript/qrcodegen.ts

@@ -1005,10 +1005,7 @@ namespace qrcodegen.QrSegment {
 		
 		// (Package-private) Returns the bit width of the segment character count field for this mode object at the given version number.
 		public numCharCountBits(ver: int): int {
-			if      ( 1 <= ver && ver <=  9)  return this.numBitsCharCount[0];
+			return this.numBitsCharCount[Math.floor((ver + 7) / 17)];
-			else if (10 <= ver && ver <= 26)  return this.numBitsCharCount[1];
-			else if (27 <= ver && ver <= 40)  return this.numBitsCharCount[2];
-			else  throw "Version number out of range";
 		}
 		
 	}