immutabilité

Immutability is a concept primarily found in computer science and programming, referring to the characteristic of an object whose state cannot be modified after it has been created. Once an immutable object is initialized with its values, those values remain fixed for its entire lifetime. Any operation that appears to modify an immutable object actually creates a new object with the modified state, leaving the original object unchanged.

This principle is fundamental in many programming paradigms, particularly in functional programming. Immutability simplifies reasoning about program behavior because the state of an object is guaranteed not to change unexpectedly. This can prevent a class of bugs related to shared mutable state, where multiple parts of a program might be accessing and modifying the same data, leading to race conditions and unpredictable outcomes.

Languages like Haskell and Clojure heavily embrace immutability. In languages like Java or Python, while not strictly enforced by default for all objects, immutable data types such as strings and tuples are common and offer significant benefits. The use of immutable objects also aids in concurrent programming, as there's no need for locks or synchronization mechanisms to protect data from simultaneous modifications, because modifications simply don't happen to existing objects.

The trade-off for these benefits can sometimes be performance. Creating new objects for every modification might seem inefficient, but often, optimizations like structural sharing can mitigate this cost. Despite potential performance considerations, the enhanced predictability and reduced complexity offered by immutability make it a valuable tool in software development.