Chapter 5, Problem 25E

Program Plan Intro

Interpreter:

• Interpreter executes each statement of a program at a time.
• It calls recursive functions for “statement”, “expression”, “factor”, “term” and “Identifier” to execute a statement.
• It allows arithmetic operations addition, subtraction, multiplication, division and exponentiation.

Explanation of Solution

b. Trace for input “v = x * ( y – w ) - - z”;

Statement()    v = x * ( y – w ) - - z;

readId()    v = x * ( y – w ) - - z;

expression()    x * (y – w ) - - z;

term()    x * ( y – w ) - - z;

factor()    x * ( y – w ) - - z;

readId()    x * ( y – w ) - - z;

factor()    ( y – w ) - - z;

checking ‘(’    ( y – w ) - - z;

  expression()            y – w ) - - z;

  term()            y – w ) - - z;

  factor()        y – w ) - - z;

  readId()    y – w ) - - z;

  term()            w )     - - z;

  factor()        w )     - - z;

  readId()    w ) - - z;

  checking ‘)’            ) - - z;

  term()                   �...