private static Expression GenerateOperation(ExpressionEnumerables.operations operation, Expression left, Expression right)
{
Expression exp = null;
switch (operation)
{
case (ExpressionEnumerables.operations.SUM):
exp = Expression.Add(left, right);
break;
case (ExpressionEnumerables.operations.SUBTRACT):
exp = Expression.Subtract(left, right);
break;
case (ExpressionEnumerables.operations.MULTIPLY):
exp = Expression.Multiply(left, right);
break;
case (ExpressionEnumerables.operations.DIVIDE):
exp = Expression.Divide(left, right);
break;
case (ExpressionEnumerables.operations.NEGATE):
exp = Expression.Negate(right);
break;
case (ExpressionEnumerables.operations.POWER):
exp = Expression.Power(left, right);
break;
default:
break;
}
return(exp);
}
private static string GenerateExpression(ExpressionEnumerables.operations operation, string input, List <ComplexExpression> expressionList, List <ParameterExpression> parameters)
{
var expReg = string.Empty;
char splitChar = '+';
switch (operation)
{
case (ExpressionEnumerables.operations.MULTIPLY):
expReg = "(\\w+\\s*[*]\\s*\\w+)";
splitChar = '*'; break;
case (ExpressionEnumerables.operations.SUM):
expReg = "(\\w+\\s*[+]\\s*\\w+)";
splitChar = '+'; break;
case (ExpressionEnumerables.operations.SUBTRACT):
expReg = "(\\w+\\s*[-]\\s*\\w+)";
splitChar = '-'; break;
case (ExpressionEnumerables.operations.NEGATE):
expReg = "(?:[(+*/ -)])([-]\\w+)";
splitChar = '-'; break;
case (ExpressionEnumerables.operations.DIVIDE):
expReg = "(\\w+\\s*[/]\\s*\\w+)";
splitChar = '/'; break;
case (ExpressionEnumerables.operations.POWER):
expReg = "(\\w+\\s*[\\^]\\s*\\w+)";
splitChar = '^'; break;
}
var regex = new Regex(expReg);
var matches = regex.Matches(input);
while (matches.Count > 0)
{
foreach (var match in matches)
{
var item = ((Match)match).Groups[1].Value;
var values = item.Split(splitChar);
var expression = GenerateOperation(operation, CheckParameter(values[0], parameters, expressionList), CheckParameter(values[1], parameters, expressionList));
string varName = "internal_val_" + expressionList.Count().ToString();
expressionList.Add(new ComplexExpression()
{
Expression = expression, VariableName = varName
});
input = input.Replace(item, varName);
}
matches = regex.Matches(input);
}
return(input);
}
