Cleared up issue with parsing ints

+ Endianness was all out of whack
+ Everything is currently handled as little endian, easy to add a config for endianness later
+ num-bigint comes in clutch, it now handles the shifting of bits

src/byte_stream/mod.rs

@@ -1,4 +1,5 @@
 use std::fmt::{Display, Formatter};
+use num_bigint::BigUint;
 
 #[derive(Clone, Debug)]
 pub enum ByteStreamError {
@@ -32,13 +33,14 @@ pub struct ByteStream {
     data: Vec<u8>,
 }
 
+
 impl ByteStream {
     pub fn get_bytes(&self, bit_ndx: usize, bit_count: usize) -> Result<Vec<u8>, ByteStreamError> {
         let byte_ndx = bit_ndx / 8;
         let bits_before = (bit_ndx % 8) as u8;
         let bits_in_last_byte = ((bit_ndx + bit_count - bits_before as usize) % 8) as u8;
-        let byte_count = if bit_count >= 8 { bit_count / 8 } else { 1 };
-        let bytes_needed = if bits_before != 0 {
+        let byte_count = ((bit_count as f32) / (8.0)).ceil() as usize;
+        let bytes_needed = if (bits_before as usize + bit_count) % 8 != 0 && !(bits_before as usize + bit_count < 8){
             byte_count + 1
         } else {
             byte_count
@@ -48,21 +50,13 @@ impl ByteStream {
             return Err(ByteStreamError::OutOfRange);
         }
 
-        let mut byte_stream = self.data[byte_ndx..byte_ndx + bytes_needed].to_vec();
+        let byte_stream = self.data[byte_ndx..byte_ndx + bytes_needed].to_vec();
 
-        if bits_before != 0 {
-            let mut carry: u8 = 0;
-            for _ in 0..bits_before {
-                for k in (0..bytes_needed).rev() {
-                    let next: u8 = (byte_stream[k] & 0x01) << 7;
-                    byte_stream[k] = (byte_stream[k] >> 1) | carry;
+        let number = BigUint::from_bytes_le(&byte_stream) >> bits_before;
 
-                    carry = next;
-                }
-            }
-        }
+        let mut byte_stream = number.to_bytes_le();
 
-        if bytes_needed > byte_count {
+        if bytes_needed > byte_count && bytes_needed == byte_stream.len() {
             byte_stream.pop();
         }
 
@@ -105,11 +99,11 @@ mod tests {
 
     #[test]
     fn test_get_bytes_with_shift_in_byte() {
-        let bytes: Vec<u8> = vec![0xff, 0x00, 0x55];
+        let bytes: Vec<u8> = vec![0x5f, 0x00, 0x55];
         let bit_stream = ByteStream::from(bytes.clone());
 
         let new_bytes = bit_stream.get_bytes(4, 4).unwrap();
-        assert_eq!(vec![0x0f], new_bytes);
+        assert_eq!(vec![0x05], new_bytes);
     }
 
     #[test]