private LuaValue PrefixUnaryOperation(string Operator, Term RightOperand, LuaTable enviroment)
{
LuaValue rightValue = RightOperand.Evaluate(enviroment);
switch (Operator)
{
case "-":
var number = rightValue as LuaNumber;
if (number != null)
{
return new LuaNumber(-number.Number);
}
else
{
LuaFunction func = GetMetaFunction("__unm", rightValue, null);
if (func != null)
{
return func.Invoke(new LuaValue[] { rightValue });
}
}
break;
case "#":
var table = rightValue as LuaTable;
if (table != null)
{
return new LuaNumber(table.Length);
}
var str = rightValue as LuaString;
if (str != null)
{
return new LuaNumber(str.Text.Length);
}
if ((rightValue.MetaTable.GetValue("__len") != null) && ((rightValue.MetaTable.GetValue("__len") as LuaFunction) != null))
return (rightValue.MetaTable.GetValue("__len") as LuaFunction).Invoke(new LuaValue[] { });
break;
case "not":
var rightBool = rightValue as LuaBoolean;
if (rightBool != null)
{
return LuaBoolean.From(!rightBool.BoolValue);
}
break;
}
return LuaNil.Nil;
}
// Operator-precedence parsing algorithm
private static Term BuildExpressionTree(Term leftTerm, LinkedListNode<object> node)
{
string oper = node.Value as string;
var rightNode = node.Next;
Term rightTerm = rightNode.Value as Term;
if (rightNode.Next == null) // last node
{
return new Operation(oper, leftTerm, rightTerm);
}
else
{
string nextOper = rightNode.Next.Value as string;
if (OperTable.IsPrior(oper, nextOper))
{
return BuildExpressionTree(new Operation(oper, leftTerm, rightTerm), rightNode.Next);
}
else
{
return new Operation(oper, leftTerm, BuildExpressionTree(rightTerm, rightNode.Next));
}
}
}
public Operation(string oper, Term left, Term right)
{
this.Operator = oper;
this.LeftOperand = left == null ? null : left.Simplify();
this.RightOperand = right == null ? null : right.Simplify();
}
private LuaValue InfixBinaryOperation(Term LeftOperand, string Operator, Term RightOperand, LuaTable enviroment)
{
LuaValue leftValue = LeftOperand.Evaluate(enviroment);
LuaValue rightValue = RightOperand.Evaluate(enviroment);
switch (Operator)
{
case "+":
var left = leftValue as LuaNumber;
var right = rightValue as LuaNumber;
if (left != null && right != null)
{
return new LuaNumber(left.Number + right.Number);
}
else
{
LuaFunction func = GetMetaFunction("__add", leftValue, rightValue);
if (func != null)
{
return func.Invoke(new LuaValue[] { leftValue, rightValue });
}
}
break;
case "-":
left = leftValue as LuaNumber;
right = rightValue as LuaNumber;
if (left != null && right != null)
{
return new LuaNumber(left.Number - right.Number);
}
else
{
LuaFunction func = GetMetaFunction("__sub", leftValue, rightValue);
if (func != null)
{
return func.Invoke(new LuaValue[] { leftValue, rightValue });
}
}
break;
case "*":
left = leftValue as LuaNumber;
right = rightValue as LuaNumber;
if (left != null && right != null)
{
return new LuaNumber(left.Number * right.Number);
}
else
{
LuaFunction func = GetMetaFunction("__mul", leftValue, rightValue);
if (func != null)
{
return func.Invoke(new LuaValue[] { leftValue, rightValue });
}
}
break;
case "/":
left = leftValue as LuaNumber;
right = rightValue as LuaNumber;
if (left != null && right != null)
{
return new LuaNumber(left.Number / right.Number);
}
else
{
LuaFunction func = GetMetaFunction("__div", leftValue, rightValue);
if (func != null)
{
return func.Invoke(new LuaValue[] { leftValue, rightValue });
}
}
break;
case "%":
left = leftValue as LuaNumber;
right = rightValue as LuaNumber;
if (left != null && right != null)
{
return new LuaNumber(left.Number % right.Number);
}
else
{
LuaFunction func = GetMetaFunction("__mod", leftValue, rightValue);
if (func != null)
{
return func.Invoke(new LuaValue[] { leftValue, rightValue });
}
}
break;
case "^":
left = leftValue as LuaNumber;
right = rightValue as LuaNumber;
if (left != null && right != null)
{
return new LuaNumber(Math.Pow(left.Number, right.Number));
}
else
{
LuaFunction func = GetMetaFunction("__pow", leftValue, rightValue);
if (func != null)
{
return func.Invoke(new LuaValue[] { leftValue, rightValue });
}
}
break;
case "==":
return LuaBoolean.From(leftValue.Equals(rightValue));
case "~=":
return LuaBoolean.From(leftValue.Equals(rightValue) == false);
case "<":
int? compare = Compare(leftValue, rightValue);
if (compare != null)
{
return LuaBoolean.From(compare < 0);
}
else
{
LuaFunction func = GetMetaFunction("__lt", leftValue, rightValue);
if (func != null)
{
return func.Invoke(new LuaValue[] { leftValue, rightValue });
}
}
break;
case ">":
compare = Compare(leftValue, rightValue);
if (compare != null)
{
return LuaBoolean.From(compare > 0);
}
else
{
LuaFunction func = GetMetaFunction("__gt", leftValue, rightValue);
if (func != null)
{
return func.Invoke(new LuaValue[] { leftValue, rightValue });
}
}
break;
case "<=":
compare = Compare(leftValue, rightValue);
if (compare != null)
{
return LuaBoolean.From(compare <= 0);
}
else
{
LuaFunction func = GetMetaFunction("__le", leftValue, rightValue);
if (func != null)
{
return func.Invoke(new LuaValue[] { leftValue, rightValue });
}
}
break;
case ">=":
compare = Compare(leftValue, rightValue);
if (compare != null)
{
return LuaBoolean.From(compare >= 0);
}
else
{
LuaFunction func = GetMetaFunction("__ge", leftValue, rightValue);
if (func != null)
{
return func.Invoke(new LuaValue[] { leftValue, rightValue });
}
}
break;
case "..":
if ((leftValue is LuaString || leftValue is LuaNumber) &&
(rightValue is LuaString || rightValue is LuaNumber))
{
return new LuaString(string.Concat(leftValue, rightValue));
}
else
{
LuaFunction func = GetMetaFunction("__concat", leftValue, rightValue);
if (func != null)
{
return func.Invoke(new LuaValue[] { leftValue, rightValue });
}
}
break;
case "and":
bool leftBool = leftValue.GetBooleanValue();
bool rightBool = rightValue.GetBooleanValue();
if (leftBool == false)
{
return leftValue;
}
else
{
return rightValue;
}
case "or":
leftBool = leftValue.GetBooleanValue();
rightBool = rightValue.GetBooleanValue();
if (leftBool == true)
{
return leftValue;
}
else
{
return rightValue;
}
}
return null;
}
public void Add(Term term)
{
Terms.AddLast(term);
}
