refvar 0.3.1

A lightweight reactive variable for simple values in Python.

refvar

refvar is a lightweight, reactive, and efficient library for managing shared values ​​in Python.

It allows you to create reactive variables that trigger callbacks whenever their content changes—even when the value is mutable, such as lists or dictionaries.

The library is ideal for situations where multiple parts of the code need to share the same centralized variable without losing the original reference.

---

🚀 Features

• Reactive variable (Ref)

• Automatic callbacks when the value changes

• Support for immutable and mutable values

• Intelligent interception of mutable methods (append, pop, update, etc.)

• Lightweight and efficient (__slots__)

• Zero external dependencies

• Simple and intuitive API:

• ref(value)

• ref(new_value) or .set()

• ref() or .get() to get the value

• ref(..., raw=True) to directly call the stored function

• .bind() / .unbind() for callbacks

---

✨ Functionalities

• Complete reactivity: any change triggers callbacks.

• Compatible with mutable types: unlike previous versions.

• Python Syntax: implements magic operators and methods.

• Direct calls with raw=True: execute the value as a function.

• Maximum lightweight: designed for performance and low memory usage.

---

🧩 What is raw=True mode?

The call:

ref(..., raw=True)

allows you to directly execute the internal value as a function, without activating the normal get/set behavior of Ref.

Examples:

1. Ref to function

log = Ref(print)

log("Hello world!", raw=True)

Output:

Hello world!

``` ```

#### 2. Ref for custom function
```python
def sum(a, b):

return a + b

f = Ref(sum)

print(f(10, 5, raw=True)) # 15

3. Keeps reactivity completely separate

The raw mode never triggers callbacks, as it does not alter ref.value, it only calls the content.

When to use raw=True?

• When you store a function inside a Ref

• When you want to use Ref as a functional proxy

• When you want to avoid reactive logic and just execute something

---

✅ Recommended Types

The Ref class works well with all types:

Immutable:

• str

• int

• float

• bool

• None

Mutable (fully supported in version 0.3.1):

• list
• dict
• set
• custom classes
• objects storable in any Python structure

---

📦 Installation

```bashpip install refvar

---

## 🔧 Basic Example (immutable)

```python``from refvar` ... `on_change(ref, new_value):`

`print("Value changed to:", new_value)`

`x.bind(on_change)`

`x(20)` # Updates and triggers callback

`print(x())` # 20
`print(x.get())` # 20
`print(x)` # Ref(20)`

---

🔧 Example with (mutable) Lists

list = Ref([])`

`def on_change(ref, new_value):`

`print("List updated:", new_value)`

`list.bind(on_change)`

`list.append(1)` # triggers callback
`list.append(2)` # triggers callback
`list.pop()` # triggers callback

Output:

Updated list: [1]
Updated list: [1, 2]
Updated list: [1]

---

🔧 Example of Using raw=True

from refvar import Ref

def double(n):

return n * 2

f = Ref(double)

print(f(5, raw=True)) # 10

---

📘 License

MIT License.