prosody
45a81d6d8777
util/iterators.lua

Find changesets by keywords by author, files, the commit message, revision number or hash, or revset expression.

Software / code / prosody

Annotate

util/iterators.lua @ 1712:45a81d6d8777

Merge waqas with Tobias. Eww.
author Matthew Wild <mwild1@gmail.com>
date Tue, 18 Aug 2009 13:03:35 +0100
parent 1660:ae2f60a20428
child 2923:b7049746bd29
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
1522
569d58d21612 Add copyright header to those files missing one
Matthew Wild <mwild1@gmail.com>
parents: 919
diff changeset
1 -- Prosody IM
569d58d21612 Add copyright header to those files missing one
Matthew Wild <mwild1@gmail.com>
parents: 919
diff changeset
2 -- Copyright (C) 2008-2009 Matthew Wild
569d58d21612 Add copyright header to those files missing one
Matthew Wild <mwild1@gmail.com>
parents: 919
diff changeset
3 -- Copyright (C) 2008-2009 Waqas Hussain
569d58d21612 Add copyright header to those files missing one
Matthew Wild <mwild1@gmail.com>
parents: 919
diff changeset
4 --
569d58d21612 Add copyright header to those files missing one
Matthew Wild <mwild1@gmail.com>
parents: 919
diff changeset
5 -- This project is MIT/X11 licensed. Please see the
569d58d21612 Add copyright header to those files missing one
Matthew Wild <mwild1@gmail.com>
parents: 919
diff changeset
6 -- COPYING file in the source package for more information.
569d58d21612 Add copyright header to those files missing one
Matthew Wild <mwild1@gmail.com>
parents: 919
diff changeset
7 --
569d58d21612 Add copyright header to those files missing one
Matthew Wild <mwild1@gmail.com>
parents: 919
diff changeset
8
919
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
9 --[[ Iterators ]]--
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
10
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
11 -- Reverse an iterator
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
12 function reverse(f, s, var)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
13 local results = {};
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
14
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
15 -- First call the normal iterator
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
16 while true do
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
17 local ret = { f(s, var) };
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
18 var = ret[1];
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
19 if var == nil then break; end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
20 table.insert(results, 1, ret);
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
21 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
22
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
23 -- Then return our reverse one
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
24 local i,max = 0, #results;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
25 return function (results)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
26 if i<max then
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
27 i = i + 1;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
28 return unpack(results[i]);
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
29 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
30 end, results;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
31 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
32
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
33 -- Iterate only over keys in a table
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
34 local function _keys_it(t, key)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
35 return (next(t, key));
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
36 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
37 function keys(t)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
38 return _keys_it, t;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
39 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
40
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
41 -- Iterate only over values in a table
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
42 function values(t)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
43 local key, val;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
44 return function (t)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
45 key, val = next(t, key);
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
46 return val;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
47 end, t;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
48 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
49
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
50 -- Given an iterator, iterate only over unique items
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
51 function unique(f, s, var)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
52 local set = {};
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
53
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
54 return function ()
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
55 while true do
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
56 local ret = { f(s, var) };
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
57 var = ret[1];
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
58 if var == nil then break; end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
59 if not set[var] then
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
60 set[var] = true;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
61 return var;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
62 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
63 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
64 end;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
65 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
66
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
67 --[[ Return the number of items an iterator returns ]]--
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
68 function count(f, s, var)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
69 local x = 0;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
70
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
71 while true do
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
72 local ret = { f(s, var) };
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
73 var = ret[1];
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
74 if var == nil then break; end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
75 x = x + 1;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
76 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
77
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
78 return x;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
79 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
80
1659
6092fc9b078b util.iterators: Add head() iterator, to return the first n items
Matthew Wild <mwild1@gmail.com>
parents: 1522
diff changeset
81 -- Return the first n items an iterator returns
6092fc9b078b util.iterators: Add head() iterator, to return the first n items
Matthew Wild <mwild1@gmail.com>
parents: 1522
diff changeset
82 function head(n, f, s, var)
6092fc9b078b util.iterators: Add head() iterator, to return the first n items
Matthew Wild <mwild1@gmail.com>
parents: 1522
diff changeset
83 local c = 0;
6092fc9b078b util.iterators: Add head() iterator, to return the first n items
Matthew Wild <mwild1@gmail.com>
parents: 1522
diff changeset
84 return function (s, var)
6092fc9b078b util.iterators: Add head() iterator, to return the first n items
Matthew Wild <mwild1@gmail.com>
parents: 1522
diff changeset
85 if c >= n then
6092fc9b078b util.iterators: Add head() iterator, to return the first n items
Matthew Wild <mwild1@gmail.com>
parents: 1522
diff changeset
86 return nil;
6092fc9b078b util.iterators: Add head() iterator, to return the first n items
Matthew Wild <mwild1@gmail.com>
parents: 1522
diff changeset
87 end
6092fc9b078b util.iterators: Add head() iterator, to return the first n items
Matthew Wild <mwild1@gmail.com>
parents: 1522
diff changeset
88 c = c + 1;
6092fc9b078b util.iterators: Add head() iterator, to return the first n items
Matthew Wild <mwild1@gmail.com>
parents: 1522
diff changeset
89 return f(s, var);
6092fc9b078b util.iterators: Add head() iterator, to return the first n items
Matthew Wild <mwild1@gmail.com>
parents: 1522
diff changeset
90 end, s;
6092fc9b078b util.iterators: Add head() iterator, to return the first n items
Matthew Wild <mwild1@gmail.com>
parents: 1522
diff changeset
91 end
6092fc9b078b util.iterators: Add head() iterator, to return the first n items
Matthew Wild <mwild1@gmail.com>
parents: 1522
diff changeset
92
1660
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
93 function tail(n, f, s, var)
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
94 local results, count = {}, 0;
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
95 while true do
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
96 local ret = { f(s, var) };
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
97 var = ret[1];
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
98 if var == nil then break; end
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
99 results[(count%n)+1] = ret;
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
100 count = count + 1;
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
101 end
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
102
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
103 if n > count then n = count; end
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
104
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
105 local pos = 0;
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
106 return function ()
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
107 pos = pos + 1;
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
108 if pos > n then return nil; end
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
109 return unpack(results[((count-1+pos)%n)+1]);
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
110 end
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
111 --return reverse(head(n, reverse(f, s, var)));
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
112 end
ae2f60a20428 util.iterators: Add tail() iterator, to return the last n items
Matthew Wild <mwild1@gmail.com>
parents: 1659
diff changeset
113
919
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
114 -- Convert the values returned by an iterator to an array
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
115 function it2array(f, s, var)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
116 local t, var = {};
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
117 while true do
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
118 var = f(s, var);
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
119 if var == nil then break; end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
120 table.insert(t, var);
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
121 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
122 return t;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
123 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
124
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
125 -- Treat the return of an iterator as key,value pairs,
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
126 -- and build a table
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
127 function it2table(f, s, var)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
128 local t, var = {};
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
129 while true do
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
130 var, var2 = f(s, var);
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
131 if var == nil then break; end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
132 t[var] = var2;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
133 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
134 return t;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
135 end