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docs/quick-start/bind.md

@@ -104,8 +104,3 @@ For example, `vm->bind__add__` is preferred over `vm->bind_method<1>(type, "__ad
 ### Bind a property
 
 You can use `vm->property(...)` to create a `property` object and assign it to an type object.
-
-### Further reading
-
-See [linalg.h](https://github.com/blueloveTH/pocketpy/blob/main/src/linalg.h) for a complete example that uses all the binding functions
-for `vec2`, `vec3` and `mat3x3` types.

docs/quick-start/example.md

@@ -0,0 +1,93 @@
+---
+icon: dot
+label: 'Complete example'
+order: 0
+---
+
+In this example, we will create a `linalg` module
+and implement a `vec2` type with some methods.
+And make them available in python just like this.
+
+```python
+from linalg import vec2
+
+# construct a vec2
+a = vec2(1.0, 2.0)
+b = vec2(0.0, -1.0)
+
+# add two vec2
+print(a + b)    # vec2(1.0, 1.0)
+
+# set x component
+a.x = 8.0
+print(a)        # vec2(8.0, 2.0)
+
+# use dot method
+print(a.dot(b)) # -2.0
+```
+
+### Implement `Vec2` struct in cpp
+
+```cpp
+struct Vec2{
+    float x, y;
+    Vec2() : x(0.0f), y(0.0f) {}
+    Vec2(float x, float y) : x(x), y(y) {}
+    Vec2(const Vec2& v) : x(v.x), y(v.y) {}
+    Vec2 operator+(const Vec2& v) const { return Vec2(x + v.x, y + v.y); }
+    float dot(const Vec2& v) const { return x * v.x + y * v.y; }
+};
+```
+
+### Create `PyVec2` wrapper
+
+```cpp
+struct PyVec2: Vec2 {
+    PY_CLASS(PyVec2, linalg, vec2)
+
+    PyVec2() : Vec2() {}
+    PyVec2(const Vec2& v) : Vec2(v) {}
+    PyVec2(const PyVec2& v) : Vec2(v) {}
+
+    static void _register(VM* vm, PyObject* mod, PyObject* type){
+        vm->bind_constructor<3>(type, [](VM* vm, ArgsView args){
+            float x = CAST_F(args[1]);
+            float y = CAST_F(args[2]);
+            return VAR(Vec2(x, y));
+        });
+
+        vm->bind__repr__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj){
+            PyVec2& self = _CAST(PyVec2&, obj);
+            std::stringstream ss;
+            ss << "vec2(" << self.x << ", " << self.y << ")";
+            return VAR(ss.str());
+        });
+
+        vm->bind__add__(OBJ_GET(Type, type), [](VM* vm, PyObject* obj, PyObject* other){
+            PyVec2& self = _CAST(PyVec2&, obj);
+            PyVec2& other_ = CAST(PyVec2&, other);
+            return VAR_T(PyVec2, self + other_);
+        });
+
+        vm->bind_method<1>(type, "dot", [](VM* vm, ArgsView args){
+            PyVec2& self = _CAST(PyVec2&, args[0]);
+            PyVec2& other = CAST(PyVec2&, args[1]);
+            return VAR(self.dot(other));
+        });
+    }
+};
+```
+
+### Create `linalg` module
+
+```cpp
+void add_module_linalg(VM* vm){
+    PyObject* linalg = vm->new_module("linalg");
+    // register PyVec2
+    PyVec2::register_class(vm, linalg);
+}
+```
+
+### Further reading
+
+See [linalg.h](https://github.com/blueloveTH/pocketpy/blob/main/src/linalg.h) for the complete implementation.