arraycase_examples

arraycase_examples — array case + array-literal function args (Enhancement-33)

Demonstrates element-wise array case statements and array literals as function arguments, using the committed openvaf-r and ngspice-46.

What was broken

Retiring the compiler's last todo!() stubs uncovered four related defects:

• case over an array crashed the compiler (not yet implemented panic) even though type inference accepted it;
• an integer-array discriminant additionally hit invalid int operation feq (whole-array variables were typed real regardless of element type);
• an array literal passed as a whole-array function input compiled but silently bound nothing — sum2('{1.0, 2.0}) returned 0 instead of 3;
• an array literal passed to an array output argument was silently accepted and the writeback skipped (scalars were always properly rejected).

The fix

case on arrays compares element-wise (an arm matches iff all elements are equal), for literals and whole-array variables, real and integer. Function inputs accept array literals via the same shared element-lowering helper (lower_array_elems); whole-array variables now carry their true element type; array output args require a caller variable. Pure front-end change. See ../Enhancement-33.md.

case (st)                    // st is integer st[0:1]
  '{0, 0}: g = 1e-3;
  '{1, 0}: g = 2e-3;
  '{1, 1}: g = 3e-3;
  default: g = 9e-3;
endcase
scale = sum2('{0.25, 0.75}); // array literal argument -> 1.0 (was silently 0)

Run

python3 verify_arraycase.py

Checks (ALL PASS): compiles (used to panic); the integer-array case selects all three regions in a DC sweep (proving the literal argument reads 1.0, not 0); a real-array case matches; an array literal to an array output argument is rejected with a proper type error.