Lua (5.3) Language addition (#4804)

* starting Lua port of python implmention. Syncing commit

* Bulk of Lua module port from Python done. Not tested, only static analysis. Need to work on binary strings. Started work on flatc lua code generation

* Fixed all the basic errors to produced a binary output from the builder, don't know if it is generated correctly, but it contains data, so that must be good

* fixed binary set command that was extending the array improperly

* continued improvement

* Moved lua submodules down a directory so their names don't clash with potential other modules. Added compat module to provide Lua versioning logic

* Successful sample port from Python

* working on testing Lua code with formal tests

* continued to work on tests and fixes to code to make tests pass

* Added reading buffer test

* Changed binaryarray implmentation to use a temporary table for storing data, and then serialize it to a string when requested. This double the rate of building flatbuffers compared to the string approach.

* Didn't need encode module as it just added another layer of indirection that isn't need

* profiled reading buffers, optimizations to increase read performance of monster data to ~7 monster / millisecond

* Writing profiler improvments. Get about
~2 monsters/millisecond building rate

* removed Numpy generation from Lua (came from the Python port)

* math.pow is deprecated in Lua 5.3, so changed to ^ notation. Also added .bat script for starting Lua tests

* adding results of generate_code.bat

* simple edits for code review in PR.

* There was a buffer overflow in inserting the keywords into the unorder set for both the Lua and Python code gens. Changed insertion to use iterators.

* fixed spacing issue

* basic documenation/tutorial updates. Updated sample_binary.lua to reflect the tutorial better

* removed windows-specific build step in Lua tests

1 files changed, 7 insertions, 0 deletions

diff --git a/include/flatbuffers/idl.h b/include/flatbuffers/idl.h
index 88d9553d..55ef89d1 100644
--- a/include/flatbuffers/idl.h
+++ b/include/flatbuffers/idl.h
@@ -408,6 +408,7 @@ struct IDLOptions {
     kTs = 1 << 9,
     kJsonSchema = 1 << 10,
     kDart = 1 << 11,
+    kLua = 1 << 12,
     kMAX
   };
 
@@ -814,6 +815,12 @@ extern bool GeneratePython(const Parser &parser,
                            const std::string &path,
                            const std::string &file_name);
 
+// Generate Lua files from the definitions in the Parser object.
+// See idl_gen_lua.cpp.
+extern bool GenerateLua(const Parser &parser,
+	                    const std::string &path,
+	                    const std::string &file_name);
+
 // Generate Json schema file
 // See idl_gen_json_schema.cpp.
 extern bool GenerateJsonSchema(const Parser &parser,