Write a program in Ruby to convert a character representation of a non-negative real number to a double value without using the string-to-double conversions, must do a character-by-character conversion. Use a separate method to do the actual conversion. Note the ASCII characters for 0 through 9 are in order.

Possible strings include 1., 5.24, .5. Note . must be present.

Similar to this but it's for int: https://www.chegg.com/homework-help/questions-and-answers/perform-lexical-operations-usually-best-implemented-finite-automata-finite-state-machine---q44024222?trackid=7aww3R1H