public static Expression <Func <T, bool> > And <T>(this Expression <Func <T, bool> > left, Expression <Func <T, bool> > right, string strname)
{
var dateExpr = Expression.Parameter(typeof(T));
var parameterReplacer = new ParameterReplacer(dateExpr);
var leftwhere = parameterReplacer.Replace(left.Body);
var rightwhere = parameterReplacer.Replace(right.Body);
var body = Expression.And(leftwhere, rightwhere);
return(Expression.Lambda <Func <T, bool> >(body, dateExpr));
}
/// <summary>
/// Or condition join
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="exp_left"></param>
/// <param name="exp_right"></param>
/// <returns></returns>
public static Expression <Func <T, bool> > Or <T>(this Expression <Func <T, bool> > exp_left, Expression <Func <T, bool> > exp_right)
{
var candidateExpr = Expression.Parameter(typeof(T), "candidate");
var parameterReplacer = new ParameterReplacer(candidateExpr);
var left = parameterReplacer.Replace(exp_left.Body);
var right = parameterReplacer.Replace(exp_right.Body);
var body = Expression.Or(left, right);
return(Expression.Lambda <Func <T, bool> >(body, candidateExpr));
}
public static Expression <Func <X, Y> > Compose <X, Y, Z>(this Expression <Func <Z, Y> > outer, Expression <Func <X, Z> > inner)
{
return(Expression.Lambda <Func <X, Y> >(
ParameterReplacer.Replace(outer.Body, outer.Parameters[0], inner.Body),
inner.Parameters[0]));
}
