Design an Extensible Rule Engine

Approach: AST with Polymorphic Operator Objects The central design separates syntax from behavior. A parser builds an abstract syntax tree whose nodes describe what the rule says. The actual comparison and logical semantics live inside small operator objects, each responsible for its own validation and evaluation. This avoids a large if (operator.equals(">")) ... else if ... switch in the evaluator. Concretely, the engine has four main pieces: Values and context — FieldValue…