Function compareExpression

docs/app/js/sanddance-app.js:6114–6121

(a, b)

    value: null
});
function compareExpression(a, b) {
    if (a && b) for(let k = 0; k < expressionKeys.length; k++){
        let key = expressionKeys[k];
        if (a[key] != b[key]) return false;
    }
    else return !a && !b;
    return true;
}
const groupKeys = Object.keys({
    clause: null
});