Please write an interpreter that understands the commands input and output. Output shall do the same as echo, print or cout in real-world languages. Input shall do the same as read, input or cin: it shall return the string entered by the user. Your interpreter shall be able to execute
output("Hello "+input("What is your name ? "))
Execution will then look like:
What is your name ? Thorsten Hello Thorsten
Note that in order to execute the outer command (output) the execution of the nested (inner) command (input) is needed. input returns Thorsten in this case and output prints it. Your take how you deal with parentheses and operators like +. Please make your interpreter extendable so do not scan for "input" and "output" as keywords.