internal static string operatorName(OperatorKind kind, string name)
{
switch (kind)
{
case OperatorKind.Prefix:
return name + "_prefix";
case OperatorKind.Infix:
return name + "_infix";
case OperatorKind.Postfix:
return name + "_postfix";
default:
{
Require.NotCalled();
return null;
}
}
}
public Expression Reduce()
{
int level = 0;
while (list.Count > 1)
{
Require.True(level <= precedence.highestLevel);
// needs to be a for loop, the list gets modified in action
//forward
Opera_nd_tor item;
for (int j = 0; j < 2; ++j)
{
bool leftToRight = j == 0;
int i;
if (leftToRight)
i = -1;
else
i = list.Count;
while (true)
{
if (leftToRight)
{
i++;
if (i == list.Count)
break;
}
else
{
if (i == 0)
break;
i--;
}
item = list[i];
if (item.IsOperator && (item.Precedence == level) && (item.LeftToRight == leftToRight))
{
switch (item.Kind)
{
case OperatorKind.Infix:
{
i = i - 1;
Expression left = list[i].Expression;
Expression right = list[i + 2].Expression;
list.RemoveRange(i, 3);
list.Insert(i, item.ReduceInfix(left, right));
break;
}
case OperatorKind.Prefix:
{
Expression right = list[i + 1].Expression;
list.RemoveRange(i, 2);
list.Insert(i, item.ReducePrefix(right));
break;
}
case OperatorKind.Postfix:
{
i = i - 1;
Expression left = list[i].Expression;
list.RemoveRange(i, 2);
list.Insert(i, item.ReducePostFix(left));
break;
}
default:
{
Require.NotCalled();
break;
}
}
}
}
}
level++;
}
Expression result = list[0].Expression;
list.Clear();
return result;
}