Harbour lets a class define custom behaviour for arithmetic and
comparison operators via `OPERATOR "<sym>" ARG <name> INLINE <expr>`.
Five already had the runtime slot infrastructure (ClassDef.Operators
+ AddOperator + parent-chain copy) but parser skipped the form and
the VM ops never consulted the slots.
Parser: parseOperatorDecl captures the symbol, ARG binding, and
INLINE body into a MethodDecl with IsOperator=true and OperatorOp
set to the hbrt.Op* slot. Synthesised method name is __OP_<idx>
to keep the regular method namespace clean.
Codegen: emitClassDecl routes IsOperator members through
_def.AddOperator instead of AddMethod. Inline body generation is
shared with the MESSAGE/INLINE path (34485cd).
VM: Thread.tryBinaryOp walks the LHS object's class operator slot,
pushes args with Self bound to LHS, and returns true if the slot
is populated. Wired into Plus/Minus/Mult/Divide and Equal/NotEqual/
Less/Greater/LessEqual/GreaterEqual. Falls through to built-in
behaviour when no overload exists — non-object LHS costs one tag
check per op.
Operator symbol→slot mapping keeps `=` and `==` on the same slot
(OpEqual=8) because Five's gengo routes both to t.Equal() and the
VM doesn't distinguish strict vs non-strict equality today.
Tested (/tmp/test_operator.prg): Vec2 + - == < with per-field
results all correct.
FiveSql2 43/43, Harbour compat 56/56, Go test ALL PASS.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
CharlesKWON
66f045b97e