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Not in a loop

Velox reports Not in a loop when break or continue appears without an active loop target. Both statements are compiled as jumps whose destination is supplied by the surrounding for, while or repeat compiler.

Example​

procedure ScriptEvent(var Value: Variant);
begin
  if Value = '' then
    break; // Error: Not in a loop
end;

Use exit to leave the current procedure, or put break inside the loop it is intended to end:

procedure ScriptEvent(var Value: Variant);
begin
  while Value <> '' do
  begin
    if Value = 'stop' then
      break;
    Value := Copy(Value, 2, Length(Value));
  end;
end;

How Velox detects it​

While compiling a loop, PascalScript creates lists for unresolved break and continue bytecode offsets. Outside a loop, that target context is absent. ProcessSub recognises either keyword, sees no active offset list and emits ecNotInLoop.

Inside a loop, the compiler also emits cleanup operations for nested try, except, finally and with state before writing the jump. It later patches break to the loop end and continue to the loop's next-test or increment point.

Correction procedure​

  1. Decide whether the intended target is a loop, the current routine or an enclosing business operation.
  2. Use break only to end the nearest active loop.
  3. Use continue only to start the next iteration of the nearest active loop.
  4. Use exit to leave the current procedure; do not substitute it mechanically when later cleanup or statements are required.

Edge cases and quirks​

  • An if, case, begin..end or try block does not by itself provide a loop target.
  • In nested loops, break and continue apply only to the nearest loop.
  • break and continue are recognised case-insensitively through the identifier path.
  • Unlike Delphi's separate restriction on leaving a finally clause, this compiler path only tests whether a loop target exists. When a transfer leaves active exception or with state, Velox emits cleanup operations before the jump. Treat this as a Velox implementation detail, not portable Delphi syntax.
  • This is a compile-time error; no partial iteration occurs.
  • for - counted-loop control.
  • while - pre-test loop control.
  • repeat..until - post-test loop control.
  • Invalid jump - a goto crosses a protected structured region.

External references​