Comment by babarock

You can do something similar in any language that support booleans as keys for dictionaries/hashtables/maps/associative arrays/...

For instance in Lua:

    function abs(x)
        test = {
           [true]=-x,
           [x>0]=x,
           [x==0]=0}
        return test[true]
    end

    > print (abs(-3))
    3

To understand this code, think that `test[true]` is overwritten at initialization time by the last predicate to evaluate to True.

It's not the best way to do this, but maybe it'will help understand the above construct.