private void IterateExpressionListWithAction(
int startShift,
int endSfift,
Func <int, MathExpression> operatorCheckFunc,
Func <MathExpression, int, int> exprListUpdatincAction)
{
Debug.Assert(startShift < ExpressionList.Count || startShift >= 0,
$"Unexpected \"startShift\" = {startShift} input in IterateExpressionListWithAction()");
Debug.Assert(endSfift < ExpressionList.Count || startShift >= 0,
$"Unexpected \"endSfift\" = {endSfift} input in IterateExpressionListWithAction()");
int i = startShift;
while (i <= ExpressionList.Count - endSfift)
{
MathExpression te = operatorCheckFunc(i);
if (te == null)
{
i++;
}
else
{
i += exprListUpdatincAction(te, i);
}
}
}
/// <summary>
/// Implements functionality for parsing math function string using recursive approach.
/// </summary>
private void Parse()
{
int startCharIndex = 0;
// Extract potential math expressions
while (startCharIndex < InputText.Length)
{
MathExpression extractedExpression = GetExpression(InputText, startCharIndex);
if (!string.IsNullOrEmpty(extractedExpression.Error))
{
Error = extractedExpression.Error;
return;
}
ExpressionList.Add(extractedExpression);
startCharIndex += extractedExpression.Length;
}
// Validate consistency of expression queue (operators do not follow in a row, there are not missed values near operators)
for (int i = 0; i < ExpressionList.Count; i++)
{
string t = CheckOperatorConsistency(i);
if (!string.IsNullOrEmpty(t))
{
Error = t;
return;
}
}
// Find pow operator "^" and replace with Math.Pow()
IterateExpressionListWithAction(1, 2, DetectPowOperatorAndCookReplacement, (te, i) =>
{
ExpressionList.RemoveRange(i - 1, 3);
ExpressionList.Insert(i - 1, te);
return(0);
});
// Find missed multiply operators "*" and insert "*" expressions
IterateExpressionListWithAction(0, 2, DetectMissedMultiplyOperatorAndCookInsertment, (te, i) =>
{
ExpressionList.Insert(i + 1, te);
return(2);
});
//Join parsed and processed expressions replaced with C# code
List <string> outslist = new List <string>();
foreach (MathExpression me in ExpressionList)
{
outslist.Add(me.Replaced);
}
OutputText = string.Join("", outslist);
}
private MathExpression GetExpression(string mathFunc, int start)
{
Debug.Assert(!string.IsNullOrEmpty(mathFunc),
"\"mathExpression\" input parameter could not be null or empty");
Debug.Assert(start >= 0 && start < mathFunc.Length,
"\"start\" input parameter should be >= 0 and < mathExpression.Length");
foreach (Func <string, int, MathExpression> f in DetectorsMap.Values)
{
MathExpression te = f(mathFunc, start);
if (te != null)
{
return(te);
}
}
// If all detectors did not detect anything - return error about unknown construction
return(new MathExpression()
{
Error = $"Обнаружен неизвестный/непонятный символ \"{mathFunc[start]}\" в выражении \"{mathFunc}\" на позиции {start}"
});
}