/// <summary>
/// Sets the function that is used to process a term and produce output.
/// </summary>
/// <param name="symbolName">This is a string representation of the term name. It could be a string, number, identifier, or the label of a term.</param>
/// <param name="">The type of symbol for the symbol name.</param>
/// <param name="evaluator">The function used to evaluate the term.</param>
public void SetEvaluator(string symbolName, SymbolType symbolType, TermEvaluator evaluator)
{
var stringIdentifier = _termDatabase.StringMapper.Map(symbolName);
if (_termDatabase.CurrentFrame.TermEvaluators.ContainsKey((stringIdentifier, symbolType)))
{
throw new Exception($"Term evaluator already assigned for {symbolName}, {symbolType}");
}
_termDatabase.CurrentFrame.TermEvaluators[(stringIdentifier, symbolType)] = evaluator;
public override void Execute(AbstractMachineState state)
{
AMProgram program = (AMProgram)state.Program;
AbstractTerm X0 = ((AbstractTerm)state["X0"]).Dereference();
AbstractTerm X1 = ((AbstractTerm)state["X1"]).Dereference();
if (TermEvaluator.Evaluate(X0) == TermEvaluator.Evaluate(X1))
{
program.Next();
}
else
{
state.Backtrack();
}
}
public override void Execute(AbstractMachineState state)
{
AMProgram program = (AMProgram)state.Program;
AbstractTerm X0 = ((AbstractTerm)state["X0"]).Dereference();
AbstractTerm X1 = ((AbstractTerm)state["X1"]).Dereference();
if (X0.Unify(new ConstantTerm(TermEvaluator.Evaluate(X1).ToString())))
{
program.Next();
}
else
{
state.Backtrack();
}
}
private static void RunTest(string input, string expectedOutput, string termname, SymbolType symbolType, TermEvaluator evaluator)
{
// Arrange
var database = TestUtilities.LoadStatements(input);
database.Writer.SetEvaluator(termname, symbolType, evaluator);
// Act
database.ExecuteRewriteRules();
// Assert
var result = database.Reader.ReadCurrentFrame().ToSourceCode();
Assert.True(StringComparer.InvariantCulture.Equals(expectedOutput, result));
}
public void eval(AbstractTerm term, double expected)
{
Assert.AreEqual(expected, TermEvaluator.Evaluate(term));
}
