public final void parseVersion()

in compat/maven-artifact/src/main/java/org/apache/maven/artifact/versioning/ComparableVersion.java [642:746]
81 lines of code
23 McCabe index (conditional complexity)

    public final void parseVersion(String version) {
        this.value = version;

        items = new ListItem();

        version = version.toLowerCase(Locale.ENGLISH);

        ListItem list = items;

        Deque<Item> stack = new ArrayDeque<>();
        stack.push(list);

        boolean isDigit = false;

        boolean isCombination = false;

        int startIndex = 0;

        for (int i = 0; i < version.length(); i++) {
            char character = version.charAt(i);
            int c = character;
            if (Character.isHighSurrogate(character)) {
                // read the next character as a low surrogate and combine into a single int
                try {
                    char low = version.charAt(i + 1);
                    char[] both = {character, low};
                    c = Character.codePointAt(both, 0);
                    i++;
                } catch (IndexOutOfBoundsException ex) {
                    // high surrogate without low surrogate. Not a lot we can do here except treat it as a regular
                    // character
                }
            }

            if (c == '.') {
                if (i == startIndex) {
                    list.add(IntItem.ZERO);
                } else {
                    list.add(parseItem(isCombination, isDigit, version.substring(startIndex, i)));
                }
                isCombination = false;
                startIndex = i + 1;
            } else if (c == '-') {
                if (i == startIndex) {
                    list.add(IntItem.ZERO);
                } else {
                    // X-1 is going to be treated as X1
                    if (!isDigit && i != version.length() - 1) {
                        char c1 = version.charAt(i + 1);
                        if (Character.isDigit(c1)) {
                            isCombination = true;
                            continue;
                        }
                    }
                    list.add(parseItem(isCombination, isDigit, version.substring(startIndex, i)));
                }
                startIndex = i + 1;

                if (!list.isEmpty()) {
                    list.add(list = new ListItem());
                    stack.push(list);
                }
                isCombination = false;
            } else if (c >= '0' && c <= '9') { // Check for ASCII digits only
                if (!isDigit && i > startIndex) {
                    // X1
                    isCombination = true;

                    if (!list.isEmpty()) {
                        list.add(list = new ListItem());
                        stack.push(list);
                    }
                }

                isDigit = true;
            } else {
                if (isDigit && i > startIndex) {
                    list.add(parseItem(isCombination, true, version.substring(startIndex, i)));
                    startIndex = i;

                    list.add(list = new ListItem());
                    stack.push(list);
                    isCombination = false;
                }

                isDigit = false;
            }
        }

        if (version.length() > startIndex) {
            // 1.0.0.X1 < 1.0.0-X2
            // treat .X as -X for any string qualifier X
            if (!isDigit && !list.isEmpty()) {
                list.add(list = new ListItem());
                stack.push(list);
            }

            list.add(parseItem(isCombination, isDigit, version.substring(startIndex)));
        }

        while (!stack.isEmpty()) {
            list = (ListItem) stack.pop();
            list.normalize();
        }
    }