public static dynamic EvaluateConstExpr(Node expr, SymTable symTable)
{
try
{
switch (expr)
{
case ConstNode _:
return(expr.Value);
case CastOperator _:
return(EvaluateConstExpr(expr.Childs[0], symTable));
case DesignatorNode _:
var temp = symTable.LookUp(expr.Value.ToString());
if (temp is ConstSymbol)
{
return(((SimpleConstant)(temp as ConstSymbol).Value).Value);
}
throw new EvaluatorException("Illegal operation");
case BinOpNode _:
return(BinaryOps[(Tokenizer.TokenSubType)expr.Value](EvaluateConstExpr(expr.Childs[0], symTable),
EvaluateConstExpr(expr.Childs[1], symTable)));
case UnOpNode _:
return(UnaryOps[(Tokenizer.TokenSubType)expr.Value](EvaluateConstExpr(expr.Childs[0], symTable)));
}
}
catch (RuntimeBinderException)
{
throw new ParserException("Invalid operation in constant expression", expr.Line, expr.Position);
}
throw new InvalidOperationException($"Node of type {expr.GetType()} met in expression");
}
public ExprItem(BinaryOps op)
{
this.Op = op;
this.Priority = _priorityByOp[op];
this.Expr = null;
}