Chapter 3 Daily 02

Note: in the list of digits, we will make the smallest place value come first. In [9,0,5], the ones digit is 9.

(hd) Write a helper function take in a single integer between 0 and 15 (inclusive) and return a string containing the corresponding hexadecimal digit. The digits are 10=“A”, 11=“B”, etc.
```
 "B" == hd 11
```
(hexShow) Take in a list of values of hexadecimal digits (so integers, like [10,11]. Output a string with the hex number “AB”.
```
 "F00D" == hexShow [13,0,0,15]
```
(hexDec) Input a list of values of hexadecimal digits, like [13,0,0,15] and output the value of the actual number.
```
 61453 == hexDec [13,0,0,15]
```
Each number represents the decimal value of a base 16 digit:
```
 15*16^3 + 0*16^2 + 0*16^1 + 13*16^0
```
If you discussed this in class, write hexParse :: String -> [Int] to produce a the list of values of hexadecimal digits.
```
 [13,0,0,15] == hexParse "F00D"
```