util.iterators: Various fixes and improvements, primarily use pack() where it should...

diff --git a/util/iterators.lua b/util/iterators.lua
index 1f6aacb81a4d36e77ba23429ff2001f6cdf14ad3..8f521fc4e1056ce3948730c4d74fd88b5ea800c9 100644 (file)
--- a/util/iterators.lua
+++ b/util/iterators.lua
@@ -10,6 +10,10 @@
 
 local it = {};
 
+local t_insert = table.insert;
+local select, unpack, next = select, unpack, next;
+local function pack(...) return { n = select("#", ...), ... }; end
+
 -- Reverse an iterator
 function it.reverse(f, s, var)
        local results = {};
@@ -19,7 +23,7 @@ function it.reverse(f, s, var)
                local ret = { f(s, var) };
                var = ret[1];
                if var == nil then break; end
-               table.insert(results, 1, ret);
+               t_insert(results, 1, ret);
        end
        
        -- Then return our reverse one
@@ -55,12 +59,12 @@ function it.unique(f, s, var)
        
        return function ()
                while true do
-                       local ret = { f(s, var) };
+                       local ret = pack(f(s, var));
                        var = ret[1];
                        if var == nil then break; end
                        if not set[var] then
                                set[var] = true;
-                               return var;
+                               return unpack(ret, 1, ret.n);
                        end
                end
        end;
@@ -71,8 +75,7 @@ function it.count(f, s, var)
        local x = 0;
        
        while true do
-               local ret = { f(s, var) };
-               var = ret[1];
+               local var = f(s, var);
                if var == nil then break; end
                x = x + 1;
        end
@@ -104,7 +107,7 @@ end
 function it.tail(n, f, s, var)
        local results, count = {}, 0;
        while true do
-               local ret = { f(s, var) };
+               local ret = pack(f(s, var));
                var = ret[1];
                if var == nil then break; end
                results[(count%n)+1] = ret;
@@ -117,7 +120,8 @@ function it.tail(n, f, s, var)
        return function ()
                pos = pos + 1;
                if pos > n then return nil; end
-               return unpack(results[((count-1+pos)%n)+1]);
+               local ret = results[((count-1+pos)%n)+1];
+               return unpack(ret, 1, ret.n);
        end
        --return reverse(head(n, reverse(f, s, var)));
 end
@@ -139,7 +143,7 @@ function it.to_array(f, s, var)
        while true do
                var = f(s, var);
                if var == nil then break; end
-               table.insert(t, var);
+               t_insert(t, var);
        end
        return t;
 end