You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
86 lines
3.3 KiB
86 lines
3.3 KiB
Use in Lobster {#flatbuffers_guide_use_lobster}
|
|
==============
|
|
|
|
## Before you get started
|
|
|
|
Before diving into the FlatBuffers usage in Lobster, 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 Lobster). This
|
|
page is designed to cover the nuances of FlatBuffers usage, specific to
|
|
Lobster.
|
|
|
|
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 Lobster library code location
|
|
|
|
The code for the FlatBuffers Lobster library can be found at
|
|
`flatbuffers/lobster`. You can browse the library code on the
|
|
[FlatBuffers GitHub page](https://github.com/google/flatbuffers/tree/master/
|
|
lobster).
|
|
|
|
## Testing the FlatBuffers Lobster library
|
|
|
|
The code to test the Lobster library can be found at `flatbuffers/tests`.
|
|
The test code itself is located in [lobstertest.lobster](https://github.com/google/
|
|
flatbuffers/blob/master/tests/lobstertest.lobster).
|
|
|
|
To run the tests, run `lobster lobstertest.lobster`. To obtain Lobster itself,
|
|
go to the [Lobster homepage](http://strlen.com/lobster) or
|
|
[github](https://github.com/aardappel/lobster) to learn how to build it for your
|
|
platform.
|
|
|
|
## Using the FlatBuffers Lobster library
|
|
|
|
*Note: See [Tutorial](@ref flatbuffers_guide_tutorial) for a more in-depth
|
|
example of how to use FlatBuffers in Lobster.*
|
|
|
|
There is support for both reading and writing FlatBuffers in Lobster.
|
|
|
|
To use FlatBuffers in your own code, first generate Lobster classes from your
|
|
schema with the `--lobster` 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 Lobster:
|
|
First, import the library and the generated code. Then read a FlatBuffer binary
|
|
file into a string, which you pass to the `GetRootAsMonster` function:
|
|
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.lobster}
|
|
include "monster_generated.lobster"
|
|
|
|
let fb = read_file("monsterdata_test.mon")
|
|
assert fb
|
|
let monster = MyGame_Example_GetRootAsMonster(fb)
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
Now you can access values like this:
|
|
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.lobster}
|
|
let hp = monster.hp
|
|
let pos = monster.pos
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
As you can see, even though `hp` and `pos` are functions that access FlatBuffer
|
|
data in-place in the string buffer, they appear as field accesses.
|
|
|
|
## Speed
|
|
|
|
Using FlatBuffers in Lobster should be relatively fast, as the implementation
|
|
makes use of native support for writing binary values, and access of vtables.
|
|
Both generated code and the runtime library are therefore small and fast.
|
|
|
|
Actual speed will depend on wether you use Lobster as bytecode VM or compiled to
|
|
C++.
|
|
|
|
## Text Parsing
|
|
|
|
Lobster has full support for parsing JSON into FlatBuffers, or generating
|
|
JSON from FlatBuffers. See `samples/sample_test.lobster` for an example.
|
|
|
|
This uses the C++ parser and generator underneath, so should be both fast and
|
|
conformant.
|
|
|
|
<br>
|