private static IPropositionalLogic <T> ParseConditionInternal(IReadOnlyList <string> condition, Func <string, T, bool> conditionChecker)
{
var walker = 0;
// Will collect not fully constructed logic (ex: (e1 & ), (! )
var incompleteLogic = new Stack <IPropositionalLogic <T> >();
// Will point the top node of expression
IPropositionalLogic <T> topExpression = null;
// Will store just-evaluated complete expression
IPropositionalLogic <T> justFullExpression = null;
while (walker < condition.Count)
{
var current = condition[walker];
walker++;
switch (current)
{
case "(":
var insideString = GetParenthesisSurrounding(walker, condition, out var endIdx);
var inside = ParseConditionInternal(insideString, conditionChecker);
justFullExpression = inside;
walker = endIdx + 1;
break;
case ")":
throw new InvalidOperationException("Parenthesis mismatch!");
case "!":
incompleteLogic.Push(new NotLogic <T>());
break;
case "|":
incompleteLogic.Push(new OrLogic <T>(topExpression));
break;
case "&":
incompleteLogic.Push(new AndLogic <T>(topExpression));
break;
default:
var stringValueLogic = new ValueLogic <T>(t => conditionChecker(current, t));
justFullExpression = stringValueLogic;
break;
}
if (justFullExpression == null)
{
continue;
}
// If a full expression has appeared
if (incompleteLogic.Count > 0)
{
topExpression = incompleteLogic.Pop();
topExpression.SetRestExpression(justFullExpression);
}
else
{
topExpression = justFullExpression;
}
// Should connect all incomplete logic
while (incompleteLogic.Count > 0)
{
var temp = incompleteLogic.Pop();
temp.SetRestExpression(topExpression);
topExpression = temp;
}
justFullExpression = null;
}
return(topExpression);
}
public void SetRestExpression(IPropositionalLogic <T> e2)
{
_e2 = e2;
}
public void SetRestExpression(IPropositionalLogic <T> e1)
{
_e1 = e1;
}
public OrLogic(IPropositionalLogic <T> e1)
{
_e1 = e1;
}
public void SetRestExpression(IPropositionalLogic <T> _) => throw new InvalidOperationException("Operator expected!");
