Lecture 8: Case study: computational geometry, coverage, program generation

1. a. Install bisect_ppx using opam with

   opam install bisect_ppx
   

   b. Download and rerun the factorial example in fac.ml

   You need to perform the three required steps:

    1. ocamlbuild -use-ocamlfind -package bisect_ppx fac.native
    2. BISECT_COVERAGE=YES ./fac.native
    3. bisect-ppx-report html
   

   Alternatively, just run make fac which should perform all three.

   Check that you can recreate a coverage report.

   c. Now change the fac call in fac.ml to fac 5. Remove the old instrumentation data file, e.g., bisect068840590.coverage and rerun the three steps.

   Open the coverage report for fac.ml in _coverage/index.html and "mouse over" the coverage counts.

   Can you explain the new coverage counts?

2. Extend aexp in the VarEnv-module of lec08.ml with minus and division. You will need to extend the type aexp, the printer exp_to_string, and the generator mygen.

3. The shrinker in stmtlang.ml only shrinks statements.

   Extend stmt_shrink with shrinkers of arithmetic expressions and Boolean (relational) expressions.

4. Finally I encourage you to

   • discuss and talk to me about/investigate potential project ideas
   • get started on your project (assuming green light from me)

   I'll be happy to give input on properties, generators, etc.