prosody
d41e88b07225
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 @ 1081:d41e88b07225

configure: Change --data-dir to --datadir to make consistent with help and other dir flags
author Matthew Wild <mwild1@gmail.com>
date Fri, 01 May 2009 19:25:03 +0100
parent 919:75b8afb79143
child 1522:569d58d21612
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
919
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
1 --[[ Iterators ]]--
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
2
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
3 -- Reverse an iterator
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
4 function reverse(f, s, var)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
5 local results = {};
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
6
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
7 -- First call the normal iterator
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
8 while true do
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
9 local ret = { f(s, var) };
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
10 var = ret[1];
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
11 if var == nil then break; end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
12 table.insert(results, 1, ret);
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
13 end
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 -- Then return our reverse one
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
16 local i,max = 0, #results;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
17 return function (results)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
18 if i<max then
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
19 i = i + 1;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
20 return unpack(results[i]);
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 end, results;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
23 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
24
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
25 -- Iterate only over keys in a table
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
26 local function _keys_it(t, key)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
27 return (next(t, key));
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
28 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
29 function keys(t)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
30 return _keys_it, t;
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 values in a table
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
34 function values(t)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
35 local key, val;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
36 return function (t)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
37 key, val = next(t, key);
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
38 return val;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
39 end, t;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
40 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
41
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
42 -- Given an iterator, iterate only over unique items
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
43 function unique(f, s, var)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
44 local set = {};
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
45
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
46 return function ()
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
47 while true do
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
48 local ret = { f(s, var) };
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
49 var = ret[1];
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
50 if var == nil then break; end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
51 if not set[var] then
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
52 set[var] = true;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
53 return var;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
54 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
55 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
56 end;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
57 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
58
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
59 --[[ Return the number of items an iterator returns ]]--
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
60 function count(f, s, var)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
61 local x = 0;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
62
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
63 while true do
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
64 local ret = { f(s, var) };
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
65 var = ret[1];
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
66 if var == nil then break; end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
67 x = x + 1;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
68 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
69
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
70 return x;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
71 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
72
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
73 -- Convert the values returned by an iterator to an array
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
74 function it2array(f, s, var)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
75 local t, var = {};
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
76 while true do
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
77 var = f(s, var);
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
78 if var == nil then break; end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
79 table.insert(t, var);
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
80 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
81 return t;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
82 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
83
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
84 -- Treat the return of an iterator as key,value pairs,
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
85 -- and build a table
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
86 function it2table(f, s, var)
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
87 local t, var = {};
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
88 while true do
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
89 var, var2 = f(s, var);
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
90 if var == nil then break; end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
91 t[var] = var2;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
92 end
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
93 return t;
75b8afb79143 util.iterators: New iterators library
Matthew Wild <mwild1@gmail.com>
parents:
diff changeset
94 end