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@@ -5,87 +5,102 @@ order: 50
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---
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Add `PY_CLASS` macro into your `struct` and implement a static function `_register`.
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+Inside the `_register` function, you can bind methods and properties to the class.
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```cpp
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PY_CLASS(T, mod, name)
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+
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+// T is the struct type in cpp
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+// mod is the module name in python
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+// name is the class name in python
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```
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## Example
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+In this example, we will create a `linalg` module
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+and implement a `vec2` type with some methods.
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+And make them available in python just like this.
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+
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+```python
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+from linalg import vec2
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+
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+# construct a vec2
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+a = vec2(1.0, 2.0)
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+b = vec2(0.0, -1.0)
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+
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+# add two vec2
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+print(a + b) # vec2(1.0, 1.0)
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+
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+# set x component
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+a.x = 8.0
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+print(a) # vec2(8.0, 2.0)
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+
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+# use dot method
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+print(a.dot(b)) # -2.0
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+```
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+
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+### Implement `Vec2` struct in cpp
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+
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```cpp
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-#include "pocketpy.h"
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+struct Vec2{
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+ float x, y;
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+ Vec2() : x(0.0f), y(0.0f) {}
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+ Vec2(float x, float y) : x(x), y(y) {}
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+ Vec2(const Vec2& v) : x(v.x), y(v.y) {}
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+ Vec2 operator+(const Vec2& v) const { return Vec2(x + v.x, y + v.y); }
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+ float dot(const Vec2& v) const { return x * v.x + y * v.y; }
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+};
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+```
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-using namespace pkpy;
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+### Create `PyVec2` wrapper
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-struct Vector2 {
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- PY_CLASS(Vector2, test, Vector2)
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- float x;
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- float y;
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+```cpp
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+struct PyVec2: Vec2 {
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+ PY_CLASS(PyVec2, linalg, vec2)
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- Vector2(float x, float y) : x(x), y(y) {}
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+ PyVec2() : Vec2() {}
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+ PyVec2(const Vec2& v) : Vec2(v) {}
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+ PyVec2(const PyVec2& v) : Vec2(v) {}
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static void _register(VM* vm, PyObject* mod, PyObject* type){
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vm->bind_constructor<3>(type, [](VM* vm, ArgsView args){
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float x = CAST_F(args[1]);
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float y = CAST_F(args[2]);
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- return VAR_T(Vector2, x, y);
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+ return VAR(Vec2(x, y));
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});
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- vm->bind_method<0>(type, "__repr__", [](VM* vm, ArgsView args){
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- Vector2& self = CAST(Vector2&, args[0]);
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+ vm->bind__repr__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
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+ PyVec2& self = _CAST(PyVec2&, obj);
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std::stringstream ss;
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- ss << "Vector2(" << self.x << ", " << self.y << ")";
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+ ss << "vec2(" << self.x << ", " << self.y << ")";
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return VAR(ss.str());
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});
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- vm->bind_method<1>(type, "__add__", [](VM* vm, ArgsView args){
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- Vector2& self = CAST(Vector2&, args[0]);
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- Vector2& other = CAST(Vector2&, args[1]);
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- return VAR_T(Vector2, self.x + other.x, self.y + other.y);
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- });
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-
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- vm->bind_method<1>(type, "__sub__", [](VM* vm, ArgsView args){
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- Vector2& self = CAST(Vector2&, args[0]);
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- Vector2& other = CAST(Vector2&, args[1]);
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- return VAR_T(Vector2, self.x - other.x, self.y - other.y);
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- });
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-
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- vm->bind_method<1>(type, "__mul__", [](VM* vm, ArgsView args){
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- Vector2& self = CAST(Vector2&, args[0]);
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- f64 other = CAST_F(args[1]);
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- return VAR_T(Vector2, self.x * other, self.y * other);
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- });
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-
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- vm->bind_method<1>(type, "__truediv__", [](VM* vm, ArgsView args){
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- Vector2& self = CAST(Vector2&, args[0]);
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- f64 other = CAST_F(args[1]);
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- return VAR_T(Vector2, self.x / other, self.y / other);
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+ vm->bind__add__(PK_OBJ_GET(Type, type), [](VM* vm, PyObject* obj, PyObject* other){
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+ PyVec2& self = _CAST(PyVec2&, obj);
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+ PyVec2& other_ = CAST(PyVec2&, other);
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+ return VAR_T(PyVec2, self + other_);
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});
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- vm->bind_method<1>(type, "__eq__", [](VM* vm, ArgsView args){
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- Vector2& self = CAST(Vector2&, args[0]);
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- Vector2& other = CAST(Vector2&, args[1]);
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- return VAR(self.x == other.x && self.y == other.y);
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+ vm->bind(type, "dot(other: vec2) -> float", [](VM* vm, ArgsView args){
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+ PyVec2& self = _CAST(PyVec2&, args[0]);
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+ PyVec2& other = CAST(PyVec2&, args[1]);
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+ return VAR(self.dot(other));
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});
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}
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};
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+```
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+
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+### Create `linalg` module
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-int main(){
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- VM* vm = new VM();
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- // create a new module `test`
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- PyObject* mod = vm->new_module("test");
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- // register `Vector2` to `test` module
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- Vector2::register_class(vm, mod);
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- return 0;
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+```cpp
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+void add_module_linalg(VM* vm){
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+ PyObject* linalg = vm->new_module("linalg");
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+ // register PyVec2
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+ PyVec2::register_class(vm, linalg);
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}
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```
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-## Usage
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-
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-```python
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-from test import Vector2
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+### Further reading
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-a = Vector2(1.0, 2.0)
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-b = Vector2(-1.0, -2.0)
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-print(a + b) # Vector2(0.0, 0.0)
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-```
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+See [linalg.h](https://github.com/blueloveTH/pocketpy/blob/main/src/linalg.h) for the complete implementation.
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