Backed out changeset 63141a85beea, broke multi-session nicks

[prosody.git] / util / iterators.lua

diff --git a/util/iterators.lua b/util/iterators.lua
index d453a6946007ec618c07399c283bcc4368c1c0e8..bd150ff28cd3572ca407274a9bf4df2276e827df 100644 (file)
--- a/util/iterators.lua
+++ b/util/iterators.lua
@@ -23,18 +23,18 @@ function it.reverse(f, s, var)
        while true do
                local ret = { f(s, var) };
                var = ret[1];
-               if var == nil then break; end
+               if var == nil then break; end
                t_insert(results, 1, ret);
        end
 
        -- Then return our reverse one
        local i,max = 0, #results;
        return function (_results)
-                       if i<max then
-                               i = i + 1;
-                               return unpack(_results[i]);
-                       end
-               end, results;
+               if i<max then
+                       i = i + 1;
+                       return unpack(_results[i]);
+               end
+       end, results;
 end
 
 -- Iterate only over keys in a table
@@ -54,6 +54,15 @@ function it.values(t)
        end, t;
 end
 
+-- Iterate over the n:th return value
+function it.select(n, f, s, var)
+       return function (_s)
+               local ret = pack(f(_s, var));
+               var = ret[1];
+               return ret[n];
+       end, s, var;
+end
+
 -- Given an iterator, iterate only over unique items
 function it.unique(f, s, var)
        local set = {};
@@ -62,8 +71,8 @@ function it.unique(f, s, var)
                while true do
                        local ret = pack(f(s, var));
                        var = ret[1];
-                       if var == nil then break; end
-                       if not set[var] then
+                       if var == nil then break; end
+                       if not set[var] then
                                set[var] = true;
                                return unpack(ret, 1, ret.n);
                        end
@@ -77,7 +86,7 @@ function it.count(f, s, var)
 
        while true do
                var = f(s, var);
-               if var == nil then break; end
+               if var == nil then break; end
                x = x + 1;
        end
 
@@ -110,7 +119,7 @@ function it.tail(n, f, s, var)
        while true do
                local ret = pack(f(s, var));
                var = ret[1];
-               if var == nil then break; end
+               if var == nil then break; end
                results[(count%n)+1] = ret;
                count = count + 1;
        end
@@ -135,8 +144,8 @@ function it.filter(filter, f, s, var)
        return function (_s, _var)
                local ret;
                repeat ret = pack(f(_s, _var));
-                       var = ret[1];
-               until var == nil or filter(unpack(ret, 1, ret.n));
+                       _var = ret[1];
+               until _var == nil or filter(unpack(ret, 1, ret.n));
                return unpack(ret, 1, ret.n);
        end, s, var;
 end
@@ -157,7 +166,7 @@ function it.to_array(f, s, var)
        local t = {};
        while true do
                var = f(s, var);
-               if var == nil then break; end
+               if var == nil then break; end
                t_insert(t, var);
        end
        return t;
@@ -169,7 +178,7 @@ function it.to_table(f, s, var)
        local t, var2 = {};
        while true do
                var, var2 = f(s, var);
-               if var == nil then break; end
+               if var == nil then break; end
                t[var] = var2;
        end
        return t;