move some doc

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blueloveTH 2024-05-05 18:35:31 +08:00
parent 304cb04bea
commit 6e0452a745
2 changed files with 98 additions and 113 deletions

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@ -202,16 +202,105 @@ This specialized binding function has optimizations and result in better perform
For example, `vm->bind__add__` is preferred over `vm->bind_func(type, "__add__", 2, f_add)`. For example, `vm->bind__add__` is preferred over `vm->bind_func(type, "__add__", 2, f_add)`.
## Automatic bindings
pkpy supports automatic binding generation **only for C libraries**.
See [pkpy-bindings](https://github.com/blueloveTH/pkpy-bindings) for details.
It takes a C header file and generates a python module stub (`*.pyi`) and a C++ binding file (`*.cpp`).
## Further reading ## Further reading
See [random.cpp](https://github.com/pocketpy/pocketpy/blob/main/src/random.cpp) for an example used by `random` module. See [random.cpp](https://github.com/pocketpy/pocketpy/blob/main/src/random.cpp) for an example used by `random` module.
See [collections.cpp](https://github.com/pocketpy/pocketpy/blob/main/src/collections.cpp) for a modern implementation of `collections.deque`. See [collections.cpp](https://github.com/pocketpy/pocketpy/blob/main/src/collections.cpp) for a modern implementation of `collections.deque`.
## Reuse Lua bindings
pkpy provides a lua bridge to reuse lua bindings.
It allows you to run lua code and call lua functions in python
by embedding a lua virtual machine.
Add `lua_bridge.hpp` and `lua_bridge.cpp` in [3rd/lua_bridge](https://github.com/pocketpy/pocketpy/tree/main/3rd/lua_bridge) to your project.
Make sure `lua.h`, `lualib.h` and `lauxlib.h` are in your include path
because `lua_bridge.hpp` needs them.
The lua bridge is based on lua 5.1.5 for maximum compatibility.
lua 5.2 or higher should also work.
### Setup
Use `initialize_lua_bridge(VM*, lua_State*)` to initialize the lua bridge.
This creates a new module `lua` in your python virtual machine.
You can use `lua.dostring` to execute lua code and get the result.
And use `lua.Table()` to create a lua table.
A `lua.Table` instance in python is a dict-like object which provides a bunch of
magic methods to access the underlying lua table.
```python
class Table:
def keys(self) -> list:
"""Return a list of keys in the table."""
def values(self) -> list:
"""Return a list of values in the table."""
def items(self) -> list[tuple]:
"""Return a list of (key, value) pairs in the table."""
def __len__(self) -> int:
"""Return the length of the table."""
def __contains__(self, key) -> bool:
"""Return True if the table contains the key."""
def __getitem__(self, key): ...
def __setitem__(self, key, value): ...
def __delitem__(self, key): ...
def __getattr__(self, key): ...
def __setattr__(self, key, value): ...
def __delattr__(self, key): ...
```
Only basic types can be passed between python and lua.
The following table shows the type mapping.
If you pass an unsupported type, an exception will be raised.
| Python type | Lua type | Allow create in Python? | Reference? |
| ----------- | -------- | ---------------------- | --------- |
| `None` | `nil` | YES | NO |
| `bool` | `boolean` | YES | NO |
| `int` | `number` | YES | NO |
| `float` | `number` | YES | NO |
| `str` | `string` | YES | NO |
| `tuple` | `table` | YES | NO |
| `list` | `table` | YES | NO |
| `dict` | `table` | YES | NO |
| `lua.Table` | `table` | YES | YES |
| `lua.Function`| `function`| NO | YES |
### Example
```cpp
#include "lua_bridge.hpp"
using namespace pkpy;
int main(){
VM* vm = new VM();
// create lua state
lua_State* L = luaL_newstate();
luaL_openlibs(L);
// initialize lua bridge
initialize_lua_bridge(vm, L);
// dostring to get _G
vm->exec("import lua");
vm->exec("g = lua.dostring('return _G')");
// create a table
vm->exec("t = lua.Table()");
vm->exec("t.a = 1");
vm->exec("t.b = 2");
// call lua function
vm->exec("g.print(t.a + t.b)"); // 3
return 0;
}
```

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@ -1,104 +0,0 @@
---
icon: cpu
title: Reuse Lua Bindings
order: 17
---
!!!
This feature is available in `v1.4.0` or higher.
!!!
pkpy provides a lua bridge to reuse lua bindings.
It allows you to run lua code and call lua functions in python
by embedding a lua virtual machine.
Add `lua_bridge.hpp` and `lua_bridge.cpp` in [3rd/lua_bridge](https://github.com/pocketpy/pocketpy/tree/main/3rd/lua_bridge) to your project.
Make sure `lua.h`, `lualib.h` and `lauxlib.h` are in your include path
because `lua_bridge.hpp` needs them.
The lua bridge is based on lua 5.1.5 for maximum compatibility.
lua 5.2 or higher should also work.
### Setup
Use `initialize_lua_bridge(VM*, lua_State*)` to initialize the lua bridge.
This creates a new module `lua` in your python virtual machine.
You can use `lua.dostring` to execute lua code and get the result.
And use `lua.Table()` to create a lua table.
A `lua.Table` instance in python is a dict-like object which provides a bunch of
magic methods to access the underlying lua table.
```python
class Table:
def keys(self) -> list:
"""Return a list of keys in the table."""
def values(self) -> list:
"""Return a list of values in the table."""
def items(self) -> list[tuple]:
"""Return a list of (key, value) pairs in the table."""
def __len__(self) -> int:
"""Return the length of the table."""
def __contains__(self, key) -> bool:
"""Return True if the table contains the key."""
def __getitem__(self, key): ...
def __setitem__(self, key, value): ...
def __delitem__(self, key): ...
def __getattr__(self, key): ...
def __setattr__(self, key, value): ...
def __delattr__(self, key): ...
```
Only basic types can be passed between python and lua.
The following table shows the type mapping.
If you pass an unsupported type, an exception will be raised.
| Python type | Lua type | Allow create in Python? | Reference? |
| ----------- | -------- | ---------------------- | --------- |
| `None` | `nil` | YES | NO |
| `bool` | `boolean` | YES | NO |
| `int` | `number` | YES | NO |
| `float` | `number` | YES | NO |
| `str` | `string` | YES | NO |
| `tuple` | `table` | YES | NO |
| `list` | `table` | YES | NO |
| `dict` | `table` | YES | NO |
| `lua.Table` | `table` | YES | YES |
| `lua.Function`| `function`| NO | YES |
### Example
```cpp
#include "lua_bridge.hpp"
using namespace pkpy;
int main(){
VM* vm = new VM();
// create lua state
lua_State* L = luaL_newstate();
luaL_openlibs(L);
// initialize lua bridge
initialize_lua_bridge(vm, L);
// dostring to get _G
vm->exec("import lua");
vm->exec("g = lua.dostring('return _G')");
// create a table
vm->exec("t = lua.Table()");
vm->exec("t.a = 1");
vm->exec("t.b = 2");
// call lua function
vm->exec("g.print(t.a + t.b)"); // 3
return 0;
}
```