public static Expression <Func <T, bool> > Or <T>(this Expression <Func <T, bool> > one,
Expression <Func <T, bool> > another)
{
var candidateExpr = Expression.Parameter(typeof(T), "candidate");
var parameterReplacer = new ParameterReplacer(candidateExpr);
var left = parameterReplacer.Replace(one.Body);
var right = parameterReplacer.Replace(another.Body);
var body = Expression.Or(left, right);
return(Expression.Lambda <Func <T, bool> >(body, candidateExpr));
}
public static Expression <Func <T, bool> > And <T>(this Expression <Func <T, bool> > one,
Expression <Func <T, bool> > another)
{
var candidateExpr = Expression.Parameter(typeof(T), "candidate");
var parameterReplacer = new ParameterReplacer(candidateExpr);
var left = parameterReplacer.Replace(one.Body);
var right = parameterReplacer.Replace(another.Body);
var body = Expression.And(left, right);
return(Expression.Lambda <Func <T, bool> >(body, candidateExpr));
// var invokedExpr = Expression.Invoke(expr2, expr1.Parameters.Cast<Expression>());
//return Expression.Lambda<Func<T, bool>>(Expression.And(expr1.Body, invokedExpr), expr1.Parameters);
}