-
Book Overview & Buying
-
Table Of Contents
Design Patterns and Best Practices in Rust
By :
The Strategy pattern allows us to define a family of algorithms, encapsulate each one as a separate type, and make them interchangeable. This pattern enables the algorithm to vary independently from the clients that use it, providing a flexible alternative to subclassing for extending behavior.
Our calculator needs to handle various evaluation scenarios. Simple expressions require basic arithmetic, while complex expressions involve variables, functions, and nested operations. Some users want optimized evaluation that simplifies expressions before computing, while others need safe evaluation that validates expressions to catch potential errors such as division by zero.
The naive approach would use conditional logic in the evaluate method:
fn evaluate(&self, expr: &dyn Expression) -> Result<f64, String> {
match self.mode {
Mode::Standard => self.evaluate_standard...