/// <summary>
/// Static version of the Expression Evaluator
/// </summary>
/// <param name="expression">expression to be evaluated</param>
/// <param name="handler">attach a custom function handler</param>
/// <returns></returns>
public static object Evaluate(string expression, AdditionalFunctionEventHandler handler)
{
ExpressionEval expr = new ExpressionEval(expression);
expr.AdditionalFunctionEventHandler += handler;
return(expr.Evaluate());
}
/// <summary>
/// Executes the function based upon the name of the function
/// </summary>
/// <param name="name">name of the function to execute</param>
/// <param name="p">parameter list</param>
/// <returns>returned value of executed function</returns>
//[SuppressMessage("Microsoft.Maintainability", "CA1502:AvoidExcessiveComplexity")]
private object ExecuteFunction(string name, object[] p)
{
object[] parameters = null;
if (p != null)
{
parameters = (object[])p.Clone();
for (int x = 0; x < parameters.Length; x++)
{
if (parameters[x] is IExpression)
{
parameters[x] = ((IExpression)parameters[x]).Evaluate();
}
}
}
switch (name.ToLower(CultureInfo.CurrentCulture))
{
// Math functions
case "sin": return(Math.Sin(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "cos": return(Math.Cos(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "tan": return(Math.Tan(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "sec": return(1 / Math.Cos(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "csc": return(1 / Math.Sin(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "cot": return(1 / Math.Tan(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "asin": return(Math.Asin(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "acos": return(Math.Acos(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "atan": return(Math.Atan(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "sinh": return(Math.Sinh(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "cosh": return(Math.Cosh(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "tanh": return(Math.Tanh(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "abs": return(Math.Abs(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "sqrt": return(Math.Sqrt(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "ciel": return(Math.Ceiling(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "floor": return(Math.Floor(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "exp": return(Math.Exp(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "log10": return(Math.Log10(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "log": return((parameters.Length > 1) ?
Math.Log(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture), Convert.ToDouble(parameters[1], CultureInfo.CurrentCulture)) :
Math.Log(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
case "max": return(Math.Max(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture), Convert.ToDouble(parameters[1], CultureInfo.CurrentCulture)));
case "min": return(Math.Min(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture), Convert.ToDouble(parameters[1], CultureInfo.CurrentCulture)));
case "pow": return(Math.Pow(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture), Convert.ToDouble(parameters[1], CultureInfo.CurrentCulture)));
case "round": return((parameters.Length > 1) ?
Math.Round(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture), Convert.ToInt32(parameters[1], CultureInfo.CurrentCulture)) :
Math.Round(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture)));
//case "trunc": return Math.Truncate(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture));
case "e": return(Math.E);
case "pi": return(Math.PI);
//DateTime functions
case "now": return(DateTime.Now);
case "today": return(DateTime.Today);
case "mindate": return(DateTime.MinValue);
case "maxdate": return(DateTime.MaxValue);
case "monthname": return((new DateTime(2000, Convert.ToInt32(parameters[0]), 1)).ToString("MMMM"));
case "adddays": return(Convert.ToDateTime(parameters[0]).AddDays(Convert.ToInt32(parameters[1])));
case "addmonths": return(Convert.ToDateTime(parameters[0]).AddMonths(Convert.ToInt32(parameters[1])));
case "addyears": return(Convert.ToDateTime(parameters[0]).AddYears(Convert.ToInt32(parameters[1])));
case "addhours": return(Convert.ToDateTime(parameters[0]).AddHours(Convert.ToInt32(parameters[1])));
case "addminutes": return(Convert.ToDateTime(parameters[0]).AddMinutes(Convert.ToInt32(parameters[1])));
case "addseconds": return(Convert.ToDateTime(parameters[0]).AddSeconds(Convert.ToInt32(parameters[1])));
//Formatting Functions
case "fmtnum": return(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture).ToString("" + parameters[1], CultureInfo.CurrentCulture));
case "fmtdate": return(Convert.ToDateTime(parameters[0], CultureInfo.CurrentCulture).ToString("" + parameters[1], CultureInfo.CurrentCulture));
//Numerical Expression Evaluation
case "expr":
{
ExpressionEval eval = new ExpressionEval("" + parameters[0]);
eval.AdditionalFunctionEventHandler += this.AdditionalFunctionEventHandler;
eval._variables = this._variables;
return(eval.Evaluate());
}
//Casting Functions
case "cdbl": return(Convert.ToDouble(parameters[0], CultureInfo.CurrentCulture));
case "cint": return(Convert.ToInt32(parameters[0], CultureInfo.CurrentCulture));
case "clong": return(Convert.ToInt64(parameters[0], CultureInfo.CurrentCulture));
case "cuint": return(Convert.ToUInt32(parameters[0], CultureInfo.CurrentCulture));
case "culong": return(Convert.ToUInt64(parameters[0], CultureInfo.CurrentCulture));
case "cdatetime": return(Convert.ToDateTime(parameters[0], CultureInfo.CurrentCulture));
case "str": return(parameters[0].ToString());
//Logical Functions
case "iif": return(Iif(parameters));
case "case": return(Case(parameters));
//security fucntions
case "currentuserid": return(WindowsIdentity.GetCurrent().Name.ToLower());
default: return(AdditionalFunctionHelper(name, parameters));
}
}
/// <summary>
/// returns the parameters of a function
/// </summary>
/// <param name="m">regex math value</param>
/// <returns></returns>
private object [] GetParameters(Match m)
{
string strParams = "";
int nIdx = m.Index + m.Length;
int nDepth = 1;
int nLast = 0;
bool bInQuotes = false;
ArrayList ret = new ArrayList();
//Get the parameter string
while (nDepth > 0)
{
if (nIdx >= Expression.Length)
{
throw new ArgumentException("Missing ')' in Expression");
}
if (!bInQuotes && Expression[nIdx] == ')')
{
nDepth--;
}
if (!bInQuotes && Expression[nIdx] == '(')
{
nDepth++;
}
if (Expression[nIdx] == '"' && (nIdx == 0 || Expression[nIdx - 1] != '\\'))
{
bInQuotes = !bInQuotes;
}
if (nDepth > 0)
{
nIdx++;
}
}
strParams = Expression.Substring(m.Index + m.Length, nIdx - (m.Index + m.Length));
if ("" + strParams == "")
{
return(null);
}
bInQuotes = false;
for (nIdx = 0; nIdx < strParams.Length; nIdx++)
{
if (!bInQuotes && strParams[nIdx] == ')')
{
nDepth--;
}
if (!bInQuotes && strParams[nIdx] == '(')
{
nDepth++;
}
if (strParams[nIdx] == '"' && (nIdx == 0 || strParams[nIdx - 1] != '\\'))
{
bInQuotes = !bInQuotes;
}
if (!bInQuotes && nDepth == 0 && strParams[nIdx] == ',')
{
ret.Add(strParams.Substring(nLast, nIdx - nLast));
nLast = nIdx + 1;
}
}
ret.Add(strParams.Substring(nLast, nIdx - nLast));
for (nIdx = 0; nIdx < ret.Count; nIdx++)
{
ExpressionEval eval = new ExpressionEval(ret[nIdx].ToString());
eval.AdditionalFunctionEventHandler += AdditionalFunctionEventHandler;
eval._variables = this._variables;
ret[nIdx] = eval;
}
return(ret.ToArray());
}
/// <summary>
/// This will search the expression for the next token (operand, operator, etc)
/// </summary>
/// <param name="nIdx">Start Position of Search</param>
/// <returns>First character index after token.</returns>
//[SuppressMessage("Microsoft.Maintainability", "CA1502:AvoidExcessiveComplexity")]
private int NextToken(int nIdx)
{
Match mRet = null;
int nRet = nIdx;
object val = null;
//Check for preceeding white space from last token index
Match m = DefinedRegex.WhiteSpace.Match(Expression, nIdx);
if (m.Success && m.Index == nIdx)
{
return(nIdx + m.Length);
}
//Check Parenthesis
m = DefinedRegex.Parenthesis.Match(Expression, nIdx);
if (m.Success)
{
mRet = m;
}
//Check Function
if (mRet == null || mRet.Index > nIdx)
{
m = DefinedRegex.Function.Match(Expression, nIdx);
if (m.Success && (mRet == null || m.Index < mRet.Index))
{
mRet = m;
}
}
//Check Variable
if (mRet == null || mRet.Index > nIdx)
{
m = DefinedRegex.Variable.Match(Expression, nIdx);
if (m.Success && (mRet == null || m.Index < mRet.Index))
{
mRet = m; val = new Variable(m.Groups["Variable"].Value, _variables);
}
}
//Check Unary Operator
if (mRet == null || mRet.Index > nIdx)
{
m = DefinedRegex.UnaryOp.Match(Expression, nIdx);
if (m.Success && (mRet == null || m.Index < mRet.Index))
{
mRet = m; val = new UnaryOp(m.Value);
}
}
//Check Hexadecimal
if (mRet == null || mRet.Index > nIdx)
{
m = DefinedRegex.Hexadecimal.Match(Expression, nIdx);
if (m.Success && (mRet == null || m.Index < mRet.Index))
{
mRet = m; val = Convert.ToInt32(m.Value, 16);
}
}
//Check Boolean
if (mRet == null || mRet.Index > nIdx)
{
m = DefinedRegex.Boolean.Match(Expression, nIdx);
if (m.Success && (mRet == null || m.Index < mRet.Index))
{
mRet = m; val = bool.Parse(m.Value);
}
}
//Check DateTime
if (mRet == null || mRet.Index > nIdx)
{
m = DefinedRegex.DateTime.Match(Expression, nIdx);
if (m.Success && (mRet == null || m.Index < mRet.Index))
{
mRet = m; val = Convert.ToDateTime(m.Groups["DateString"].Value, CultureInfo.CurrentCulture);
}
}
//Check Timespan
if (mRet == null || mRet.Index > nIdx)
{
m = DefinedRegex.TimeSpan.Match(Expression, nIdx);
if (m.Success && (mRet == null || m.Index < mRet.Index))
{
mRet = m;
val = new TimeSpan(
int.Parse("0" + m.Groups["Days"].Value),
int.Parse(m.Groups["Hours"].Value),
int.Parse(m.Groups["Minutes"].Value),
int.Parse("0" + m.Groups["Seconds"].Value),
int.Parse("0" + m.Groups["Milliseconds"].Value)
);
}
}
//Check Numeric
if (mRet == null || mRet.Index > nIdx)
{
m = DefinedRegex.Numeric.Match(Expression, nIdx);
if (m.Success && (mRet == null || m.Index < mRet.Index))
{
while (m.Success && ("" + m.Value == ""))
{
m = m.NextMatch();
}
if (m.Success)
{
mRet = m;
val = double.Parse(m.Value, CultureInfo.CurrentCulture);
}
}
}
if (mRet == null || mRet.Index > nIdx)
{
//Check String
m = DefinedRegex.String.Match(Expression, nIdx);
if (m.Success && (mRet == null || m.Index < mRet.Index))
{
mRet = m; val = m.Groups["String"].Value.Replace("\\\"", "\"");
}
}
//Check Binary Operator
if (mRet == null || mRet.Index > nIdx)
{
m = DefinedRegex.BinaryOp.Match(Expression, nIdx);
if (m.Success && (mRet == null || m.Index < mRet.Index))
{
mRet = m; val = new BinaryOp(m.Value);
}
}
if (mRet == null)
{
throw new ArgumentException("Invalid expression construction: \"" + Expression + "\".");
}
if (mRet.Index != nIdx)
{
throw new ArgumentException(
"Invalid token in expression: [" +
Expression.Substring(nIdx, mRet.Index - nIdx).Trim() + "]"
);
}
if (mRet.Value == "(" || mRet.Value.StartsWith("$"))
{
nRet = mRet.Index + mRet.Length;
int nDepth = 1;
bool bInQuotes = false;
while (nDepth > 0)
{
if (nRet >= Expression.Length)
{
throw new ArgumentException("Missing " + (bInQuotes ? "\"" : ")") + " in Expression");
}
if (!bInQuotes && Expression[nRet] == ')')
{
nDepth--;
}
if (!bInQuotes && Expression[nRet] == '(')
{
nDepth++;
}
if (Expression[nRet] == '"' && (nRet == 0 || Expression[nRet - 1] != '\\'))
{
bInQuotes = !bInQuotes;
}
nRet++;
}
if (mRet.Value == "(")
{
ExpressionEval expr = new ExpressionEval(
Expression.Substring(mRet.Index + 1, nRet - mRet.Index - 2)
);
if (this.AdditionalFunctionEventHandler != null)
{
expr.AdditionalFunctionEventHandler += this.AdditionalFunctionEventHandler;
}
expr._variables = this._variables;
_expressionlist.Add(expr);
}
else
{
FunctionEval func = new FunctionEval(
Expression.Substring(mRet.Index, (nRet) - mRet.Index)
);
if (this.AdditionalFunctionEventHandler != null)
{
func.AdditionalFunctionEventHandler += this.AdditionalFunctionEventHandler;
}
func._variables = this._variables;
_expressionlist.Add(func);
}
}
else
{
nRet = mRet.Index + mRet.Length;
_expressionlist.Add(val);
}
return(nRet);
}
public BinaryOp(string strOp)
{
_strOp = strOp; _nPrecedence = ExpressionEval.OperatorPrecedence(strOp);
}
/// <summary>
/// Static version of the Expression Evaluator
/// </summary>
/// <param name="expression">expression to be evaluated</param>
/// <returns></returns>
public static object Evaluate(string expressionString)
{
ExpressionEval expression = new ExpressionEval(expressionString);
return(expression.Evaluate());
}