🚀 go-pugleaf

Just to see how this "problem" is handled elsewhere:  Ada must report a static
semantic error (excuse me, for those of you reading SIGPLAN) if a function
has NO return statement.  It does not have to diagnose whether the function
must execute a return statement.  If the end of a function is reached without
executing a return statement, Ada raises one of its standard exceptions
(PROGRAM_ERROR).  Interestingly enough, that exception can be handled in the
function itself, so we can include a safeguard (although such code is rarely,
if ever used).

FUNCTION F (params) RETURN INTEGER IS
  locals
BEGIN
  some hairy computation that terminates, but may or may not execute
    a return statement
EXCEPTION
  WHEN PROGRAM_ERROR => RETURN 0;
END F;

Rich Pattis