In Chapter 11. Strings and Binaries we have the Parse.exs that parses the character list representation of a decimal number.
Inside of the method _number_digits we have this operation
value * 10 + digit - ?0 that prints 1, but when I tried to do the same thing on iex it prints -47:
0 * 10 + 1 - ?0
Why am I getting different results here?