tqchen commented on a change in pull request #4628: [Object] Add String container URL: https://github.com/apache/incubator-tvm/pull/4628#discussion_r387973867
########## File path: include/tvm/runtime/container.h ########## @@ -274,7 +304,286 @@ class ADT : public ObjectRef { TVM_DEFINE_OBJECT_REF_METHODS(ADT, ObjectRef, ADTObj); }; +/*! \brief An object representing string. It's POD type. */ +class StringObj : public Object { + public: + /*! \brief The pointer to string data. */ + const char* data; + + /*! \brief The length of the string object. */ + uint64_t size; + + static constexpr const uint32_t _type_index = TypeIndex::kDynamic; + static constexpr const char* _type_key = "runtime.String"; + TVM_DECLARE_FINAL_OBJECT_INFO(StringObj, Object); + + private: + /*! \brief String object which is moved from std::string container. */ + class FromStd; + + friend class String; +}; + +/*! + * \brief Reference to string objects. + * + * \code + * + * // Example to create runtime String reference object from std::string + * std::string s = "hello world"; + * + * // You can create the reference from existing std::string + * String ref{std::move(s)}; + * + * // You can rebind the reference to another string. + * ref = std::string{"hello world2"}; + * + * // You can use the reference as hash map key + * std::unordered_map<String, int32_t> m; + * m[ref] = 1; + * + * // You can compare the reference object with other string objects + * assert(ref == "hello world", true); + * + * // You can convert the reference to std::string again + * string s2 = (string)ref; + * + * \endcode + */ +class String : public ObjectRef { + public: + /*! + * \brief Construct a new String object + * + * \param other The moved/copied std::string object + * + * \note If user passes const reference, it will trigger copy. If it's rvalue, + * it will be moved into other. + */ + explicit String(std::string other); + + /*! + * \brief Change the value the reference object points to. + * + * \param other The value for the new String + * + */ + inline String operator=(std::string other); + + /*! + * \brief Compare is equal to other std::string + * + * \param other The other string + * + * \return the comparison result + */ + bool operator==(const std::string& other) const { + return this->compare(other) == 0; + } + + /*! + * \brief Compare is not equal to other std::string + * + * \param other The other string + * + * \return the comparison result + */ + bool operator!=(const std::string& other) const { return !operator==(other); } + + /*! + * \brief Compare is equal to other char string + * + * \param other The other char string + * + * \return the comparison result + */ + bool operator==(const char* other) const { return compare(other) == 0; } + + /*! + * \brief Compare is not equal to other char string + * + * \param other The other char string + * + * \return the comparison result + */ + bool operator!=(const char* other) const { return !operator==(other); } + + /*! + * \brief Compares this String object to other + * + * \param other The String to compare with. + * + * \return zero if both char sequences compare equal. negative if this appear + * before other, positive otherwise. + */ + int compare(const String& other) const { + return memncmp(data(), other.data(), size(), other.size()); + } + + /*! + * \brief Compares this String object to other + * + * \param other The string to compare with. + * + * \return zero if both char sequences compare equal. negative if this appear + * before other, positive otherwise. + */ + int compare(const std::string& other) const { + return memncmp(data(), other.data(), size(), other.size()); + } + + /*! + * \brief Compares this to other + * + * \param other The character array to compare with. + * + * \return zero if both char sequences compare equal. negative if this appear + * before other, positive otherwise. + */ + int compare(const char* other) const { + if (other == data()) { Review comment: This seems to be not a good idea, in case other and data have different length but points to the same data content - We need to have a regression test to cover this case ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services