![]() ![]() #coding: pythonql # This example illustrates the try-catch business in PythonQL. So we can write path expression in the query language (and elsewhere in Python expressions) like this: expr where expr must evaluate to string expr where expr must evaluate to stringĭescendants step: for x in data. We have modeled our path expression on XPath, however we use a much simplified verison:Ĭhild step: for x in data. When working with nested data that has varied structure, path expressions are extremely useful. We propose the following extensions to Python( that are implemeneted in this demo preprocessor and query executor): However, group by mechanisms, outerjoins and support for semi-structured data are not handled well at all. Python has pretty advanced comprehensions, that cover a big chunk of SQL, to the point where PonyORM was able to build a whole ORM system based on comprehensions. Void serialize( const map_size_t& map_size, Args&.PythonQL is an extension to Python that allows language-integrated queries against relational, XML and JSON data, as well an Python's collections Void serialize( const arr_size_t& arr_size, Args&. Void serialize( const First& first, Rest&. variable sized serializer for any type template reserve internal buffer void reserve_buffer( const size_t size) I reccomend to use low cost but much better performance chip like ESP series. I considered to support them but I won't support them unless uClibc++ becomes much better compatibility to standard C++ library. STL library for Arduino Supportįor such boards, there are several STL libraries, like ArduinoSTL, StandardCPlusPlus, and so on.īut such libraries are mainly based on uClibc++ and it has many lack of function. Please see "Memory Management" section and ArxContainer for detail. In addtion for such boards, type aliases for following types are different from others. These macros have no effect for STL enabled boards. # define MSGPACK_MAX_MAP_SIZE 8 // msgpack objects size in one packet # define MSGPACK_MAX_ARRAY_SIZE 8 // max size of MsgPack::map_t # define MSGPACK_MAX_PACKET_BYTE_SIZE 128 // max size of MsgPack::arr_t MsgPack::object::ext holds binary data of Ext type. This object is just a dummy and do nothing. MsgPack::object::nil_t is used to pack and unpack Nil type. Type Aliases for Str / Bin / Array / Mapįor general C++ apps (not Arduino), str_t is defined as: There are some additional types are defined to express msgpack formats easily. for the detail of arx::xxx, see ArxContainer.for Map, only MsgPack::map_t ( arx::map) can be used.for Array, only T, MsgPack::arr_t ( arx::vector), and MsgPack::fix_arr_t ( arx::array) can be used.all types of NIL, Bool, Integer, Float, Str, Bin.for NO-STL Arduino, following types can be used.C-style array and pointers are supported only packing.unordered_xxx cannot be used in all Arduino.T (need to serialize(ptr, size) or pack(ptr, size)).unsigned char (need to serialize(ptr, size) or pack(ptr, size)).unsigned char* (need to serialize(ptr, size) or pack(ptr, size)).std::string or String(Arduino) ( MsgPack::str_t).You can also pack() or unpack() variable one by one. These are the lists of types which can be serialize and deserialize. load current config MsgPack::eeprom::load(config) To pack / unpack values as such collections in a simple way, please use these functions. In msgpack, there are two collection types: Array and Map.Ĭ++ containers will be converted to one of them but you can do that from individual parameters. MsgPack:: arr_t v Encode / Decode to Collections without Container MsgPack:: str_t s = "str " // std::string or String # include // input to msgpack int i = 123
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