Subnet command (#17)

* Started working on subnets

* Basic version of the subnet command

* Improved subnet command

* almost done with subnets

* improve positioning

src/core/byte.ts

@@ -0,0 +1,26 @@
+function flipBitsToZero(byte: number, numberOfBits : number) : number {
+    if(numberOfBits == 0)
+        return byte;
+    
+    const zerouOutMask = Math.pow(2, 8-numberOfBits)-1<<numberOfBits; // E.g. 11111000 for flipping first three bits
+    const result = byte & zerouOutMask; 
+
+    return result;
+}
+
+// TODO: continue here to implement getting broadcast address
+
+function flipBitsToOne(byte : number, numberOfBits : number) : number {
+    if(numberOfBits == 0) return byte;
+
+    const zerouOutMask = Math.pow(2, numberOfBits)-1; // E.g. 00000111 for flipping first three bits
+    const result = byte | zerouOutMask; 
+
+    return result;
+}
+
+function createSubnetMaskByte(numberOfBits: number) {
+    return 255<<(8-numberOfBits)&255;;
+}
+
+export {flipBitsToZero, createSubnetMaskByte, flipBitsToOne};