Objective
One of the program objectives is that students should develop:
- SO-07 : Ability to identify and formulate problems in various real-life situations that can be solved by concepts and computational models and to implement them effectively.
Assignment
When we implement user-defined functions, we need to ensure we maintain stack discipline. Local variables, including those introduced by transformation to A-Normal Form, will affect the stack. (See Stack Frame Sizes for a discussion of the issues.)
Design and implement a countVars function to calculate how much stack space an
expression will require. Your input will be a tag aexpr, and you can output an
int, with the number of stack slots it will require.
Examples
Given:
APrim2 (Plus, INumber (10L, 1), INumber (11L, 2), 3)
you should return:
0
Given:
ALet ("_prim21l", AImm (INumber (10L, 2)),
ALet ("_prim21r", AImm (INumber (10L, 3)),
APrim2 (Plus, IId ("_prim21l", 1), IId ("_prim21r", 1), 1), 1),
1)
you should return:
2
P.S. You don't need to load the entire compiler to work on this assignment, if you place your code in count.ml you can run:
$ dune utop
utop # #mod_use "syntax.ml";;
utop # #use "count.ml";;
and then test your function.