template inline const list treeSubstAssoc()

in kernel/tree.hpp [85:116]

• 24 lines of code
• 12 McCabe index (conditional complexity)

template<typename T> inline const list<T> treeSubstAssoc(const list<T>& k, const list<T>& n, const list<T>& lv) noexcept {
    if (isNull(k) || isNull(lv))
        return lv;

    // If list is an assoc and matches, substitute it
    if (isAssoc(lv)) {
        if (car<T>(lv) == car(k) && isNull(cdr(k)))
            return n;
    }

    // If list element is not an assoc, lookup children and rest of the list
    const T a = car(lv);
    if (!isAssoc(a)) {
        if (!isList(a))
            return cons<T>(a, treeSubstAssoc<T>(k, n, cdr(lv)));
        return cons<T>(treeSubstAssoc<T>(k, n, a), treeSubstAssoc<T>(k, n, cdr(lv)));
    }

    // If we found a match, substitute it and lookup children and rest of the list
    if (car<T>(a) == car(k)) {
        if (isNull(cdr(k)))
            return cons<T>(n, treeSubstAssoc<T>(k, n, cdr(lv)));
        return cons<T>(cons<T>(car<T>(a), treeSubstAssoc<T>(cdr(k), n, cdr<T>(a))), treeSubstAssoc<T>(k, n, cdr(lv)));
    }

    // No match, lookup children and rest of the list
    if (isNull(cdr<T>(a)))
        return cons<T>(a, treeSubstAssoc<T>(k, n, cdr(lv)));
    if (!isList(cadr<T>(a)))
        return cons<T>(cons<T>(car<T>(a), cons<T>(cadr<T>(a), treeSubstAssoc<T>(k, n, cddr<T>(a)))), treeSubstAssoc<T>(k, n, cdr(lv)));
    return cons<T>(cons<T>(car<T>(a), cons<T>(treeSubstAssoc<T>(k, n, cadr<T>(a)), treeSubstAssoc<T>(k, n, cddr<T>(a)))), treeSubstAssoc<T>(k, n, cdr(lv)));
}