public static RangeSet fromString()

in core/src/main/java/hudson/model/Fingerprint.java [686:772]
72 lines of code
22 McCabe index (conditional complexity)

        public static RangeSet fromString(String list, boolean skipError) {
            RangeSet rs = new RangeSet();

            // Reject malformed ranges like "1---10", "1,,,,3" etc.
            if (list.contains("--") || list.contains(",,")) {
                if (!skipError) {
                    throw new IllegalArgumentException(
                            String.format("Unable to parse '%s', expected correct notation M,N or M-N", list));
                }
                // ignore malformed notation
                return rs;
            }

            String[] items = Util.tokenize(list,",");
            if(items.length > 1 && items.length <= StringUtils.countMatches(list, ",")) {
                if (!skipError) {
                    throw new IllegalArgumentException(
                            String.format("Unable to parse '%s', expected correct notation M,N or M-N", list));
                }
                // ignore malformed notation like ",1,2" or "1,2,"
                return rs;
            }

            for (String s : items) {
                s = s.trim();
                // s is either single number or range "x-y".
                // note that the end range is inclusive in this notation, but not in the Range class
                try {
                    if (s.isEmpty()) {
                        if (!skipError) {
                            throw new IllegalArgumentException(
                                    String.format("Unable to parse '%s', expected number", list));                        }
                        // ignore "" element
                        continue;
                    }

                    if(s.contains("-")) {
                        if(StringUtils.countMatches(s, "-") > 1) {
                            if (!skipError) {
                                throw new IllegalArgumentException(String.format(
                                        "Unable to parse '%s', expected correct notation M,N or M-N", list));
                            }
                            // ignore malformed ranges like "-5-2" or "2-5-"
                            continue;
                        }
                        String[] tokens = Util.tokenize(s,"-");
                        if (tokens.length == 2) {
                            int left = Integer.parseInt(tokens[0]);
                            int right = Integer.parseInt(tokens[1]);
                            if(left < 0 || right < 0) {
                                if (!skipError) {
                                    throw new IllegalArgumentException(
                                            String.format("Unable to parse '%s', expected number above zero", list));
                                }
                                // ignore a range which starts or ends under zero like "-5-3"
                                continue;
                            }
                            if(left > right) {
                                if (!skipError) {
                                    throw new IllegalArgumentException(String.format(
                                            "Unable to parse '%s', expected string with a range M-N where M<N", list));
                                }
                                // ignore inverse range like "10-5"
                                continue;
                            }
                            rs.ranges.add(new Range(left, right+1));
                        } else {
                            if (!skipError) {
                                throw new IllegalArgumentException(
                                        String.format("Unable to parse '%s', expected string with a range M-N", list));
                            }
                            // ignore malformed text like "1-10-50"
                            continue;
                        }
                    } else {
                        int n = Integer.parseInt(s);
                        rs.ranges.add(new Range(n,n+1));
                    }
                } catch (NumberFormatException e) {
                    if (!skipError)
                        throw new IllegalArgumentException(
                                String.format("Unable to parse '%s', expected number", list));
                    // ignore malformed text
                }
            }
            return rs;
        }