(a) Write a context-free grammar for case or switch statements in the style of Pascal or C. Add semantic functions to ensure that the same label does not appear on two different arms of the construct....

(a) Write a context-free grammar for case or switch statements in the

style of Pascal or C. Add semantic functions to ensure that the same

label does not appear on two different arms of the construct.

(b) Replace your semantic functions with action routines that can be evaluated during parsing.