static CustomExpressionTree ProcessWhereStr(string whereStr)
{
var result = new CustomExpressionTree();
var junctionIndex = new List <Tuple <int, string> >();
var index2 = 0;
GetJunctionSort(whereStr, junctionIndex);
var singleExps = whereStr.Split(junctionSplit, StringSplitOptions.RemoveEmptyEntries).ToList().Select(x => x.Replace(" ", "")).Where(x => x != "");
foreach (var expression in singleExps)
{
var singleExp = expression.Split(OperSplit, StringSplitOptions.RemoveEmptyEntries).ToList().Select(x => x.Replace(" ", "")).ToArray();
var subExp = new CustomExpression {
ParameterName = singleExp[0], ParameterValue = singleExp[1]
};
var op = expression.Remove(expression.Length - singleExp[1].Length); //tail
op = op.Remove(0, singleExp[0].Length); // header
subExp.Op = op; //operation in middle
ProcessSubExp(subExp, result);
if (index2 < junctionIndex.Count)
{
var oper = junctionIndex[index2];
var item2 = oper.Item2;
result.Push(item2);
}
index2++;
}
return(result);
}
//StartWith Contains ...
static IList <BinaryExpression> Lambda <TObj>(CustomExpressionTree expressTree, ParameterExpression pe) where TObj : class
{
var flagArr = new List <int>();
var expressionList = new List <BinaryExpression>();
while (expressTree.Count > 0)
{
var stackContent = expressTree.Pop();
if (stackContent is string)
{
ProcessNonExp(flagArr, expressionList, stackContent.ToString());
continue;
}
if (stackContent is CustomExpression)
{
var currExpress = (stackContent as CustomExpression);
ProcessExp <TObj>(pe, currExpress, flagArr, expressionList);
}
}
while (flagArr.Count > 0)
{
var lastFlag = flagArr[flagArr.Count - 1];
CompositeExpByConj(lastFlag, expressionList);
flagArr.RemoveAt(flagArr.Count - 1);
}
return(expressionList);
}
static CustomExpressionTree SwapExp(CustomExpressionTree result)
{
var result2 = new CustomExpressionTree();
while (result.Count > 0)
{
result2.Push(result.Pop());
}
return(result2);
}
static Func <TObj, bool> Convert <TObj>(string whereStr) where TObj : class
{
var result = new CustomExpressionTree();
result = ProcessWhereStr(whereStr);
var result2 = SwapExp(result);
var pe = Expression.Parameter(typeof(TObj), "x");
var bianryExprestt = Lambda <TObj>(result2, pe).First();
return(Expression.Lambda <Func <TObj, bool> >(bianryExprestt, new[] { pe }).Compile());
}
static void ProcessSubExp(CustomExpression subExp, CustomExpressionTree result)
{
var index = 0;
do
{
index = subExp.ParameterName.IndexOf(ConstBrace.LeftBrace);
if (index < 0)
{
break;
}
result.Push(ConstBrace.LeftBrace);
subExp.ParameterName = subExp.ParameterName.Remove(index, 1);
} while (index >= 0);
var flagEnd = false;
var cntRightBrace = 0;
index = 0;
do
{
index = subExp.ParameterValue.IndexOf(ConstBrace.RightBrace);
if (index < 0)
{
break;
}
cntRightBrace++;
subExp.ParameterValue = subExp.ParameterValue.Remove(index, 1);
flagEnd = true;
} while (index >= 0);
result.Push(subExp);
if (flagEnd)
{
while (cntRightBrace-- > 0)
{
result.Push(ConstBrace.RightBrace);
}
}
}
