Class Diff

Fleece/Support/diff_match_patch.hh:108–157

  * Class representing one diff operation.
  */
  class Diff {
   public:
    Operation operation;
    // One of: INSERT, DELETE or EQUAL.

    string_t text;
    // The text associated with this diff operation.

    /**
     * Constructor.  Initializes the diff with the provided values.
     * @param operation One of INSERT, DELETE or EQUAL.
     * @param text The text being applied.
     */
    Diff(Operation _operation, const string_t &_text) : operation(_operation), text(_text) {}
    Diff() =default;

    /**
     * Display a human-readable version of this Diff.
     * @return text version.
     */
    string_t toString() const {
      string_t prettyText = text;
      // Replace linebreaks with Pilcrow signs.
      for (typename string_t::iterator i = prettyText.begin(); i != prettyText.end(); ++i)
        if (traits::to_wchar(*i) == L'\n') *i = traits::from_wchar(L'\u00b6');
      return traits::cs(L"Diff(") + strOperation(operation) + traits::cs(L",\"") + prettyText + traits::cs(L"\")");
    }

    /**
     * Is this Diff equivalent to another Diff?
     * @param d Another Diff to compare against
     * @return true or false
     */
    bool operator==(const Diff &d) const {
      return (d.operation == this->operation) && (d.text == this->text);
    }
    bool operator!=(const Diff &d) const { return !(operator == (d)); }

    static string_t strOperation(Operation op) {
      switch (op) {
        case INSERT:
          return traits::cs(L"INSERT");
        case DELETE:
          return traits::cs(L"DELETE");
        case EQUAL:
          return traits::cs(L"EQUAL");
      }
      throw string_t(traits::cs(L"Invalid operation."));
    }
  };

  typedef std::list<Diff> Diffs;