How to write an empty block

Question

How do you write an empty block? For example, in C, you can have { }. But in BCPL, the equivalent $( $) is a syntax error because a block needs at least one statement. So how can you make the following compile?

let foo() be $(
    test bar then $(
        //to do
    $) else $(
        writes("baz*n")
    $)
$)

Answer 1

For now, you could just switch to unless to achieve the desired result:

// TODO: refactor to use "test", and code other case.
unless bar do $(
    writes("baz*n")
$)

If you really want to leave it as is, any null-type statement (one having no functional effect) will do. An example of that could be something like:

test bar then $(
    // TODO: replace with real code later.
    bar := bar
$) else $(
    writes("baz*n")
$)