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* 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
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Use in Lua
Before you get started
Before diving into the FlatBuffers usage in Lua, it should be noted that the [Tutorial](@ref flatbuffers_guide_tutorial) page has a complete guide to general FlatBuffers usage in all of the supported languages (including Lua). This page is designed to cover the nuances of FlatBuffers usage, specific to Lua.
You should also have read the [Building](@ref flatbuffers_guide_building)
documentation to build flatc and should be familiar with
[Using the schema compiler](@ref flatbuffers_guide_using_schema_compiler) and
[Writing a schema](@ref flatbuffers_guide_writing_schema).
FlatBuffers Lua library code location
The code for the FlatBuffers Lua library can be found at
flatbuffers/lua. You can browse the library code on the
FlatBuffers GitHub page.
Testing the FlatBuffers Lua library
The code to test the Lua library can be found at flatbuffers/tests.
The test code itself is located in [luatest.lua](https://github.com/google/
flatbuffers/blob/master/tests/luatest.lua).
To run the tests, use the [LuaTest.sh](https://github.com/google/flatbuffers/ blob/master/tests/LuaTest.sh) shell script.
Note: This script requires Lua 5.3 to be installed.
Using the FlatBuffers Lua library
Note: See [Tutorial](@ref flatbuffers_guide_tutorial) for a more in-depth example of how to use FlatBuffers in Lua.
There is support for both reading and writing FlatBuffers in Lua.
To use FlatBuffers in your own code, first generate Lua classes from your
schema with the --lua option to flatc. Then you can include both
FlatBuffers and the generated code to read or write a FlatBuffer.
For example, here is how you would read a FlatBuffer binary file in Lua:
First, require the module and the generated code. Then read a FlatBuffer binary
file into a string, which you pass to the GetRootAsMonster function:
-- require the library
local flatbuffers = require("flatbuffers")
-- require the generated code
local monster = require("MyGame.Sample.Monster")
-- read the flatbuffer from a file into a string
local f = io.open('monster.dat', 'rb')
local buf = f:read('*a')
f:close()
-- parse the flatbuffer to get an instance to the root monster
local monster1 = monster.GetRootAsMonster(buf, 0)
Now you can access values like this:
-- use the : notation to access member data
local hp = monster1:Hp()
local pos = monster1:Pos()
Text Parsing
There currently is no support for parsing text (Schema's and JSON) directly from Lua, though you could use the C++ parser through SWIG or ctypes. Please see the C++ documentation for more on text parsing.