// return a list of the fields in a tuple.
let fields = module{
    tpl = NULL,
} => {
    let reducer = macro(acc, field, value) =>  acc + [field];

    let result = reduce reducer [], (mod.tpl);
};

// return a list of the values in a tuple.
let values = module{
    tpl = NULL,
} => {
    let reducer = macro(acc, field, value) =>  acc + [value];

    let result = reduce reducer [], (mod.tpl);
};

let iter = module{
    tpl = NULL,
} => {
    let reducer = macro(acc, field, value) =>  acc + [[field, value]];
    
    let result = reduce reducer [], (mod.tpl);
};

let strip_nulls = module{
    tpl = NULL,
} => {
    let filterer = macro(name, value) =>  value != NULL;

    let result = filter filterer (mod.tpl);
};