Loop

Used to conditionally restart a block execution from its first instruction.

loop cond<bool>

loop name<id> cond<bool>

Restarts the execution of the target block if cond is true. The new execution starts from the first instruction in the block. The current scope of the block is closed, and a new scope is opened.

If name is given, the target is the innermost enclosing block of that name. Otherwise, the target is the innermost enclosing block.

    block {
        # ...
        loop (> i 0);
    };

    block b0 () {
        block {
            # ...
            loop b0 true;
        };
    };

Looping is allowed on passing blocks.