LEAVE

 ────LEAVE────┬────────┬────;────────────────
                └──name──┘

LEAVE is used to cause an immediate exit from one or more repetitive DO loops (that is, any DO construct other than a simple DO loop).

Processing of the group of instructions is terminated, and control is passed to the instruction following the END clause as though the END clause had been encountered and the termination condition had been met normally. However, on exit, the control variable, if any, will contain the value it had when the LEAVE instruction was processed.

If name is not specified, LEAVE terminates the innermost active repetitive loop. If name is specified, it must be the name of the control variable of a currently active loop which may be the innermost loop; that loop (and any active loops inside it) is then terminated. Control then passes to the clause following the END clause that matches the DO clause of the selected loop.

Example:

do i=1 to 5
  say i
  if i=3 then leave
  end
/* Would display the numbers:   1, 2, 3  */

Notes:

• If specified, name must match the one on the DO instruction in all respects except case. No substitution for compound variables is carried out when the comparison is made.

• A loop is active if it is currently being processed. If during execution of a loop, a subroutine is called or an INTERPRET instruction is processed, the loop becomes inactive until the subroutine has returned or the INTERPRET instruction has completed. LEAVE cannot be used to terminate an inactive loop.

• If more than one active loop uses the same control variable, the innermost one is the one selected by LEAVE.