Question

Context Free Grammars and Parse Trees

1. Write a grammar rule for parsing an ifStatement. Specifically, you should consider the following: an ifStatement should
   1. Start with the ‘if’ keyword,
   2. Require parenthesis around the condition,
   3. Can have any expression for the condition (you do not need to write a rule for expressions, you can assume one exists named expression),
   4. The condition is followed by the ‘then’ keyword,
   5. Which is followed by zero or more statements (you do not need to write a rule for statements, you can assume one exists named statements)
   6. Followed by the ‘else’ keyword,
   7. Followed by zero or more statements,
   8. Followed by the ‘end’ keyword.

Example ifStatement:

if ( x * y + 10 ) then

   x = 1

   y = 2

else

   x = 0

   y = 1

end

Answer 1