protected virtual object EvalAtom(ParseTree tree, params object[] paramlist)
{
throw new NotImplementedException();
}
protected virtual object EvalStart(ParseTree tree, params object[] paramlist)
{
return("Could not interpret input; no semantics implemented.");
}
protected object GetValue(ParseTree tree, TokenType type, int index)
{
return(GetValue(tree, type, ref index));
}
/// <summary>
/// this implements the evaluation functionality, cannot be used directly
/// </summary>
/// <param name="tree">the parsetree itself</param>
/// <param name="paramlist">optional input parameters</param>
/// <returns>a partial result of the evaluation</returns>
internal object Eval(ParseTree tree, params object[] paramlist)
{
object Value = null;
switch (Token.Type)
{
case TokenType.Start:
Value = EvalStart(tree, paramlist);
break;
case TokenType.Conditional:
Value = EvalConditional(tree, paramlist);
break;
case TokenType.Identifier:
Value = EvalIdentifier(tree, paramlist);
break;
case TokenType.BooleanExpr:
Value = EvalBooleanExpr(tree, paramlist);
break;
case TokenType.CompareExpr:
Value = EvalCompareExpr(tree, paramlist);
break;
case TokenType.AddExpr:
Value = EvalAddExpr(tree, paramlist);
break;
case TokenType.MultExpr:
Value = EvalMultExpr(tree, paramlist);
break;
case TokenType.PowerExpr:
Value = EvalPowerExpr(tree, paramlist);
break;
case TokenType.Params:
Value = EvalParams(tree, paramlist);
break;
case TokenType.Method:
Value = EvalMethod(tree, paramlist);
break;
case TokenType.Array:
Value = EvalArray(tree, paramlist);
break;
case TokenType.QualifiedName:
Value = EvalQualifiedName(tree, paramlist);
break;
case TokenType.UnaryExpr:
Value = EvalUnaryExpr(tree, paramlist);
break;
case TokenType.Atom:
Value = EvalAtom(tree, paramlist);
break;
default:
Value = Token.Text;
break;
}
return(Value);
}
public ParseTree Parse(string input)
{
tree = new ParseTree();
return(Parse(input, tree));
}
