[toolslive]

there's a bunch of research related to 'stack based query languages' google for SBQL.

Anyway, in the specific case of joy is more difficult to dig up. Here's an example (I know it, because I implemented it): https://github.com/openvstorage/arakoon/blob/lsl/src/system/...

    "script1_" true 
    "script2_" false
    0
    [POP; 1; ADD] 
    FOLD_RANGE

The above program has basically calculates the number of keys between "script1_" inclusive and "script2_" exclusive. It's really compact flexible and powerful.

Now, before you run off and think about implementing this yourself. First have a look at kitten: https://kittenlang.org/