Interpreter Design Pattern
The Interpreter Design Pattern is a behavioral design pattern used to define a grammar for a language and provide an interpreter to evaluate sentences in that language. It involves creating a class hierarchy where each class represents a rule in the grammar, allowing complex expressions to be parsed and interpreted. This pattern is particularly useful for implementing domain-specific languages (DSLs), mathematical expressions, or query languages.
Developers should learn the Interpreter pattern when they need to interpret or evaluate expressions in a custom language, such as in rule-based systems, configuration files, or query parsers. It is valuable for scenarios where the grammar is relatively simple and stable, as it provides a clear structure for parsing and executing expressions without relying on external libraries. However, it can become complex for large grammars, so it's best suited for small, well-defined languages.