// Demonstrates: do-while loop, infinite loop with stop simulation,
// and the iteration limit (zero-delay infinite loop error).
//
// Expected output (basic example):
// (0,0)TOP.m      :n=5
// (1,0)TOP.m      :n=4
// (2,0)TOP.m      :n=3
// (3,0)TOP.m      :n=2
// (4,0)TOP.m      :n=1
// (5,0)TOP.m      :done.
// Simulation stopped at time (5,0)

// --8<-- [start:basic]
module Top
    submodule m : Countdown
end module

module Countdown
    decl $int n;$
    init $n = 5;$
    behavior
        // loop body always executes at least once before the condition is checked
        do
            $log << endl << "n=" << n;$;
            $n = n - 1;$;
            wait(1, 0);
        while (n > 0) end do;
        $log << endl << "done.";$;
        stop simulation;
    end behavior
end module
// --8<-- [end:basic]


// --8<-- [start:infinite_loop]
// Infinite loop idiom: while(1) end do combined with stop simulation or stop behavior
module InfiniteLoop
    decl $int count;$
    init $count = 0;$
    behavior
        do
            $
            count = count + 1;
            log << endl << "count=" << count;
            $;
            wait(1, 0);
            if (count >= 3) then
                stop simulation;
            end if;
        while (1) end do;
    end behavior
end module
// --8<-- [end:infinite_loop]


// --8<-- [start:iteration_limit]
// WARNING: a do-while body with no wait statement will exceed the iteration limit.
// The simulator enforces a maximum number of instantaneous iterations per phase
// to detect non-terminating zero-delay loops. This module will raise an error.
module IterationLimitError
behavior
    do
        $log << endl << "spinning...";$;
        // No wait here: the loop never converges; the kernel raises an error.
    while (1) end do;
end behavior
end module
// --8<-- [end:iteration_limit]