diff --git a/python/qrcodegen.py b/python/qrcodegen.py
index 7b1a537..3c5bc29 100644
--- a/python/qrcodegen.py
+++ b/python/qrcodegen.py
@@ -368,8 +368,7 @@ class QrCode(object):
 			ecc = rs.get_remainder(dat)
 			if i < numshortblocks:
 				dat.append(0)
-			dat.extend(ecc)
-			blocks.append(dat)
+			blocks.append(dat + ecc)
 		assert k == len(data)
 		
 		# Interleave (not concatenate) the bytes from every block into a single sequence
diff --git a/rust/src/lib.rs b/rust/src/lib.rs
index c4f5f59..ce68e6f 100644
--- a/rust/src/lib.rs
+++ b/rust/src/lib.rs
@@ -240,7 +240,7 @@ impl QrCode {
 	// Note that Unix newlines (\n) are always used, regardless of the platform.
 	pub fn to_svg_string(&self, border: i32) -> String {
 		assert!(border >= 0, "Border must be non-negative");
-		let mut result: String = String::new();
+		let mut result = String::new();
 		result += "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
 		result += "<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\" \"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n";
 		let dimension = self.size.checked_add(border.checked_mul(2).unwrap()).unwrap();
@@ -308,7 +308,7 @@ impl QrCode {
 		// Calculate error correction code and pack bits
 		let size: i32 = self.size;
 		// errcorrlvl is uint2, mask is uint3
-		let mut data: u32 = self.errorcorrectionlevel.format_bits() << 3 | (mask.value() as u32);
+		let data: u32 = self.errorcorrectionlevel.format_bits() << 3 | (mask.value() as u32);
 		let mut rem: u32 = data;
 		for _ in 0 .. 10 {
 			rem = (rem << 1) ^ ((rem >> 9) * 0x537);
@@ -420,8 +420,7 @@ impl QrCode {
 		let rs = ReedSolomonGenerator::new(blockecclen);
 		let mut k: usize = 0;
 		for i in 0 .. numblocks {
-			let mut dat = Vec::<u8>::with_capacity(shortblocklen + 1);
-			dat.extend_from_slice(&data[k .. k + shortblocklen - blockecclen + ((i >= numshortblocks) as usize)]);
+			let mut dat = data[k .. k + shortblocklen - blockecclen + ((i >= numshortblocks) as usize)].to_vec();
 			k += dat.len();
 			let ecc: Vec<u8> = rs.get_remainder(&dat);
 			if i < numshortblocks {
diff --git a/typescript/qrcodegen.ts b/typescript/qrcodegen.ts
index 081cea1..a31605a 100644
--- a/typescript/qrcodegen.ts
+++ b/typescript/qrcodegen.ts
@@ -286,11 +286,11 @@ namespace qrcodegen {
 		// based on the given mask and this object's error correction level field.
 		private drawFormatBits(mask: int): void {
 			// Calculate error correction code and pack bits
-			let data: int = this.errorCorrectionLevel.formatBits << 3 | mask;  // errCorrLvl is uint2, mask is uint3
+			const data: int = this.errorCorrectionLevel.formatBits << 3 | mask;  // errCorrLvl is uint2, mask is uint3
 			let rem: int = data;
 			for (let i = 0; i < 10; i++)
 				rem = (rem << 1) ^ ((rem >>> 9) * 0x537);
-			let bits = (data << 10 | rem) ^ 0x5412;  // uint15
+			const bits = (data << 10 | rem) ^ 0x5412;  // uint15
 			if (bits >>> 15 != 0)
 				throw "Assertion error";
 			
@@ -322,7 +322,7 @@ namespace qrcodegen {
 			let rem: int = this.version;  // version is uint6, in the range [7, 40]
 			for (let i = 0; i < 12; i++)
 				rem = (rem << 1) ^ ((rem >>> 11) * 0x1F25);
-			let bits: int = this.version << 12 | rem;  // uint18
+			const bits: int = this.version << 12 | rem;  // uint18
 			if (bits >>> 18 != 0)
 				throw "Assertion error";