/src/lib/abilities/internal/hoard.e

  1-- This file is part of a Liberty Eiffel library.
  2-- See the full copyright at the end.
  3--
  4deferred class HOARD[E_]
  5   --
  6   -- A hoard of objects is a collation of many objects sharing the same type. This meta type defines some
  7   -- traversal features using agents, as well as very simple hoard properties: `count' and `is_empty'.
  8   --
  9
 10feature {ANY} -- Counting:
 11   count: INTEGER
 12         -- Number of available items in the hoard.
 13         --
 14         -- See also `is_empty'
 15      deferred
 16      ensure
 17         Result >= 0
 18      end
 19
 20   is_empty: BOOLEAN
 21         -- Is the hoard empty ?
 22         --
 23         -- See also `count'.
 24      deferred
 25      ensure
 26         definition: Result = (count = 0)
 27      end
 28
 29feature {ANY} -- Agent-based features:
 30   for_each (action: PROCEDURE[TUPLE[E_]])
 31         -- Apply `action' to every item of `Current'.
 32         --
 33         -- See also `for_all', `exists', `aggregate'.
 34      require
 35         action /= Void
 36      deferred
 37      end
 38
 39   frozen do_all (action: ROUTINE[TUPLE[E_]])
 40         -- Apply `action' to every item of `Current'.
 41         --
 42         -- See also `for_all', `exists', `aggregate'.
 43      obsolete "Use `for_each` instead. This feature is not secure because it accepts a FUNCTION, the result of which is lost."
 44      require
 45         action /= Void
 46      local
 47         p: PROCEDURE[TUPLE[E_]]
 48      do
 49         if p ?:= action then
 50            p ::= action
 51         else
 52            p := agent (a: ROUTINE[TUPLE[E_]]; e: E_) do a.call([e]) end (action, ?)
 53         end
 54         for_each(p)
 55      end
 56
 57   for_all (test: PREDICATE[TUPLE[E_]]): BOOLEAN
 58         -- Do all items satisfy `test'?
 59         --
 60         -- See also `for_each', `exists', `aggregate'.
 61      require
 62         test /= Void
 63      deferred
 64      end
 65
 66   exists (test: PREDICATE[TUPLE[E_]]): BOOLEAN
 67         -- Does at least one item satisfy `test'?
 68         --
 69         -- See also `for_each', `for_all', `aggregate'.
 70      require
 71         test /= Void
 72      deferred
 73      end
 74
 75   aggregate (action: FUNCTION[TUPLE[E_, E_], E_]; initial: E_): E_
 76         -- Aggregate all the elements starting from the initial value.
 77         --
 78         -- See also `for_each', `for_all', `exists'.
 79      require
 80         action /= Void
 81      deferred
 82      end
 83
 84end -- class HOARD
 85--
 86-- Copyright (C) 2009-2017: by all the people cited in the AUTHORS file.
 87--
 88-- Permission is hereby granted, free of charge, to any person obtaining a copy
 89-- of this software and associated documentation files (the "Software"), to deal
 90-- in the Software without restriction, including without limitation the rights
 91-- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 92-- copies of the Software, and to permit persons to whom the Software is
 93-- furnished to do so, subject to the following conditions:
 94--
 95-- The above copyright notice and this permission notice shall be included in
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 97--
 98-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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