/src/lib/abilities/traversable.e

 1-- This file is part of a Liberty Eiffel library.
 2-- See the full copyright at the end.
 3--
 4deferred class TRAVERSABLE[E_]
 5   -- A `TRAVERSABLE[E_]' is a finite readable sequence of objects of type E_.
 6   -- For instance, `COLLECTION's and `STRING's are `TRAVERSABLE'.
 7   --
 8   -- A good performance should always be obtained by sequentially accessing a `TRAVERSABLE' with increasing
 9   -- indexes (from `lower' to `upper'), as demonstrated in the following code snippet :
10   --
11   --  from
12   --     i := a_traversable.lower
13   --  until
14   --     i > a_traversable.upper
15   --  loop
16   --     do_something_with(a_traversable.item(i))
17   --     i := i + 1
18   --  end
19   --
20   -- Other accessing methods (including random access and sequential access from `upper' to `lower') may or
21   -- may not lead to acceptable performance, depending on the particular implementation of `TRAVERSABLE'.
22
23inherit
24   ITERABLE[E_]
25      undefine -- because INDEXABLE features are more performant
26         for_each, for_all, exists, aggregate,
27         out_in_tagged_out_memory
28      end
29   INDEXABLE[E_]
30
31feature {ANY}
32   enumerate: ENUMERATE[E_]
33      local
34         items: TRAVERSABLE[E_]
35      do
36         if items ?:= Current then
37            items ::= Current
38            create Result.make(items)
39         end
40      end
41
42end -- class TRAVERSABLE
43--
44-- Copyright (C) 2009-2017: by all the people cited in the AUTHORS file.
45--
46-- Permission is hereby granted, free of charge, to any person obtaining a copy
47-- of this software and associated documentation files (the "Software"), to deal
48-- in the Software without restriction, including without limitation the rights
49-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
50-- copies of the Software, and to permit persons to whom the Software is
51-- furnished to do so, subject to the following conditions:
52--
53-- The above copyright notice and this permission notice shall be included in
54-- all copies or substantial portions of the Software.
55--
56-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
57-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
58-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
59-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
60-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
61-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
62-- THE SOFTWARE.