How can I develop a simple program interpreter using c++ that follows this grammar?

-> start stop

-> ; { }

-> = | input | show | show "string" | show ' ' | int

-> {}

-> "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" | "J" | "K" | "L" | "M" | "N" | "O" | "P" | "Q" | "R" | "S" | "T" | "U" | "V" | "W" | "X" | "Y" | "Z"

-> + | - | * | / |

's must be declared before use and cannot be declared twice, show and show "string" will work as cout does, and the goal is to allow a text file to be read and executed with relevant c++ code? For example, a text file opened with the string start int X = 5;

show X;

stop

would translate and execute to:

int X = 5;

cout << X;