1using System;
 2using System.Collections.Generic;
 3using System.Linq;
 4
 5namespace gorilla.commons.utility
 6{
 7    static public class MappingExtensions
 8    {
 9        static public Output map_using<Input, Output>(this Input item, Converter<Input, Output> conversion)
10        {
11            return conversion(item);
12        }
13
14        static public Output map_using<Input, Output>(this Input item, Mapper<Input, Output> mapper)
15        {
16            return map_using(item, x => mapper.map_from(x));
17        }
18
19        static public Output map_using<Input, Output>(this Input item, Mapper mapper)
20        {
21            return map_using(item, x => mapper.map_from<Input, Output>(x));
22        }
23
24        static public IEnumerable<Output> map_all_using<Input, Output>(this IEnumerable<Input> items,
25                                                                       Converter<Input, Output> mapper)
26        {
27            return null == items ? new List<Output>() : items.Select(x => mapper(x));
28        }
29
30        static public IEnumerable<Output> map_all_using<Input, Output>(this IEnumerable<Input> items,
31                                                                       Mapper<Input, Output> mapper)
32        {
33            return map_all_using(items, x => mapper.map_from(x));
34        }
35
36        static public IEnumerable<Output> map_all_using<Input, Output>(this IEnumerable<Input> items,
37                                                                       Mapper mapper)
38        {
39            return map_all_using(items, x => mapper.map_from<Input, Output>(x));
40        }
41
42        static public Mapper<Left, Right> then<Left, Middle, Right>(this Mapper<Left, Middle> left,
43                                                                    Mapper<Middle, Right> right)
44        {
45            return new ChainedMapper<Left, Middle, Right>(left, right);
46        }
47    }
48}