bool Eval()

in rapidjson/internal/regex.h [375:427]
49 lines of code
9 McCabe index (conditional complexity)

    bool Eval(Stack<Allocator>& operandStack, Operator op) {
        switch (op) {
            case kConcatenation:
                RAPIDJSON_ASSERT(operandStack.GetSize() >= sizeof(Frag) * 2);
                {
                    Frag e2 = *operandStack.template Pop<Frag>(1);
                    Frag e1 = *operandStack.template Pop<Frag>(1);
                    Patch(e1.out, e2.start);
                    *operandStack.template Push<Frag>() = Frag(e1.start, e2.out, Min(e1.minIndex, e2.minIndex));
                }
                return true;

            case kAlternation:
                if (operandStack.GetSize() >= sizeof(Frag) * 2) {
                    Frag e2 = *operandStack.template Pop<Frag>(1);
                    Frag e1 = *operandStack.template Pop<Frag>(1);
                    SizeType s = NewState(e1.start, e2.start, 0);
                    *operandStack.template Push<Frag>() = Frag(s, Append(e1.out, e2.out), Min(e1.minIndex, e2.minIndex));
                    return true;
                }
                return false;

            case kZeroOrOne:
                if (operandStack.GetSize() >= sizeof(Frag)) {
                    Frag e = *operandStack.template Pop<Frag>(1);
                    SizeType s = NewState(kRegexInvalidState, e.start, 0);
                    *operandStack.template Push<Frag>() = Frag(s, Append(e.out, s), e.minIndex);
                    return true;
                }
                return false;

            case kZeroOrMore:
                if (operandStack.GetSize() >= sizeof(Frag)) {
                    Frag e = *operandStack.template Pop<Frag>(1);
                    SizeType s = NewState(kRegexInvalidState, e.start, 0);
                    Patch(e.out, s);
                    *operandStack.template Push<Frag>() = Frag(s, s, e.minIndex);
                    return true;
                }
                return false;

            default: 
                RAPIDJSON_ASSERT(op == kOneOrMore);
                if (operandStack.GetSize() >= sizeof(Frag)) {
                    Frag e = *operandStack.template Pop<Frag>(1);
                    SizeType s = NewState(kRegexInvalidState, e.start, 0);
                    Patch(e.out, s);
                    *operandStack.template Push<Frag>() = Frag(e.start, s, e.minIndex);
                    return true;
                }
                return false;
        }
    }