source: mainline/uspace/dist/src/sysel/lib/map.sy

--
-- Copyright (c) 2010 Jiri Svoboda
-- All rights reserved.
--
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that the following conditions
-- are met:
--
-- o Redistributions of source code must retain the above copyright
--   notice, this list of conditions and the following disclaimer.
-- o Redistributions in binary form must reproduce the above copyright
--   notice, this list of conditions and the following disclaimer in the
--   documentation and/or other materials provided with the distribution.
-- o The name of the author may not be used to endorse or promote products
--   derived from this software without specific prior written permission.
--
-- THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
-- IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
-- OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
-- IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
-- INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
-- NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-- DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-- THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
-- THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
--

-- Trivial map.
class Map/tkey/tvalue is
        var data : List/(MapPair/tkey/tvalue);

        -- New empty map.
        new() is
                data = new List/(MapPair/tkey/tvalue)();
        end

        fun Set(key : tkey; value : tvalue) is
                if KeyPresent(key) then
                        Remove(key);
                end

                var p : MapPair/tkey/tvalue;
                p = new MapPair/tkey/tvalue();

                p.Key = key;
                p.Value = value;
                data.Append(p);
        end

        -- Return internal list node associated with key @a key.
        fun lookup_node(key : tkey) : ListNode/(MapPair/tkey/tvalue) is
                var node : ListNode/(MapPair/tkey/tvalue);

                node = data.First;
                while node != nil do
                        if node.Data.Key == key then
                                return node;
                        end

                        node = node.Next;
                end

                return nil;
        end

        fun KeyPresent(key : tkey) : bool is
                return lookup_node(key) != nil;
        end

        fun Get(key : tkey) : tvalue is
                var node : ListNode/(MapPair/tkey/tvalue);

                node = lookup_node(key);
                return node.Data.Value;
        end

        fun Remove(key : tkey) is
                var node : ListNode/(MapPair/tkey/tvalue);

                node = lookup_node(key);
                node.Remove();
        end

        prop self[key : tkey] : tvalue is
                get is
                        return Get(key);
                end
                set value is
                        Set(key, value);
                end
        end

        fun GetEnumerator() : IEnumerator/tkey is
                return new MapEnumerator/tkey/tvalue(data.get_first());
        end
end

class MapPair/tkey/tvalue is
        var Key : tkey;
        var Value : tvalue;
end

class MapEnumerator/tkey/tvalue : IEnumerator/tkey is
        var first : ListNode/(MapPair/tkey/tvalue);
        var current : ListNode/(MapPair/tkey/tvalue);
        var started : bool;

        new(first_node : ListNode/(MapPair/tkey/tvalue)) is
                first = first_node;
                current = nil;
                started = false;
        end

        fun MoveNext() : bool is
                if started then
                        current = current.Next;
                else
                        current = first;
                        started = true;
                end

                return current != nil;
        end

        prop Data : tkey is
                get is
                        return current.Data.Key;
                end
        end
end