/// <summary>
/// Replaces the variables in the expression with values from <paramref name="scope"/>.
/// </summary>
/// <param name="scope">The scope object containing variable values.</param>
/// <param name="result">[out] The new expression containing the replaced variables.</param>
/// <returns><c>true</c> if substitution was successful, <c>false</c> if something went wrong, in which case <paramref name="result"/> will likely be a <see cref="ParseErrorExpression"/>.</returns>
public override bool ReplaceVariables(InterpreterScope scope, out ExpressionBase result)
{
// user-defined functions should be evaluated (expanded) immediately.
if (!Evaluate(scope, out result))
{
return(false);
}
if (result == null)
{
var functionCall = scope.GetContext <FunctionCallExpression>();
if (functionCall != null)
{
result = new ParseErrorExpression(Name.Name + " did not return a value", functionCall.FunctionName);
}
else
{
result = new ParseErrorExpression(Name.Name + " did not return a value");
}
return(false);
}
return(true);
}
private ExpressionBase LocateParameter(InterpreterScope scope, string name)
{
var functionCall = scope.GetContext <FunctionCallExpression>();
if (functionCall != null)
{
var nameEnumerator = Parameters.GetEnumerator();
var valueEnumerator = functionCall.Parameters.GetEnumerator();
while (nameEnumerator.MoveNext() && valueEnumerator.MoveNext())
{
if (nameEnumerator.Current.Name == name)
{
return(valueEnumerator.Current);
}
}
}
return(null);
}