public string eval(string problem)
{
problem = "(" + problem + ")";
System.Diagnostics.Debug.WriteLine("Evaluating Problem: " + problem);
UnitProblemContextDescription context = getNextUnitProblemContextDescription(problem);
while (true)
{
// .... solve problem in context
System.Diagnostics.Debug.WriteLine("Evaluating New Context: " + context.context);
context.solution = solveContextProblem(context.context);
// .... replace solved context in problem with solution
context.problem = replaceSubString(context.problem, context.solution, context.head, context.tail);
context = getNextUnitProblemContextDescription(context.problem);
// .... if problem is solved
if (context.head == context.tail)
{
if (context.problem == null)
{
return("");
}
else
{
return(context.problem);
}
}
}
}
public UnitProblemContextDescription getNextUnitProblemContextDescription(string problem)
{
UnitProblemContextDescription context = new UnitProblemContextDescription();
context.problem = problem;
for (int i = 0; i < problem.Length; i++)
{
switch (problem.ElementAt <char>(i))
{
case '(':
context.head = i;
break;
case ')':
context.tail = i;
context.context = problem.Substring(context.head + 1, context.tail - context.head - 1);
return(context);
}
}
return(context);
}