Package tools.refinery.interpreter.matchers.psystem

Interface IExpressionEvaluator

public interface IExpressionEvaluator
An expression evaluator is used to execute arbitrary Java code during pattern matching. In order to include the evaluation in the planning seemlessly it is expected from the evaluator implementors to report all used PVariables by name.

  • Method Details

    • getShortDescription

      String getShortDescription()
      A textual description of the expression. Used only for debug purposes, but must not be null.

    • getInputParameterNames

      Iterable<String> getInputParameterNames()
      All input parameter names should be reported correctly.

    • evaluateExpression

      Object evaluateExpression(IValueProvider provider) throws Exception
      The expression evaluator code
      Parameters:
      provider - the value provider is an engine-specific way of reading internal variable tuples to evaluate the expression with
      Returns:
      the result of the expression: in case of predicate evaluation the return value must be true or false; otherwise the result can be an arbitrary object. No null values should be returned.
      Throws:
      Exception