1 files changed, 39 insertions, 34 deletions

diff --git a/util/array.lua b/util/array.lua
index 2d58e7fb..ea520f6b 100644
--- a/util/array.lua
+++ b/util/array.lua
@@ -1,7 +1,7 @@
 -- Prosody IM
 -- Copyright (C) 2008-2010 Matthew Wild
 -- Copyright (C) 2008-2010 Waqas Hussain
--- 
+--
 -- This project is MIT/X11 licensed. Please see the
 -- COPYING file in the source package for more information.
 --
@@ -11,13 +11,15 @@ local t_insert, t_sort, t_remove, t_concat
 
 local setmetatable = setmetatable;
 local math_random = math.random;
+local math_floor = math.floor;
 local pairs, ipairs = pairs, ipairs;
 local tostring = tostring;
+local type = type;
 
 local array = {};
 local array_base = {};
 local array_methods = {};
-local array_mt = { __index = array_methods, __tostring = function (array) return "{"..array:concat(", ").."}"; end };
+local array_mt = { __index = array_methods, __tostring = function (self) return "{"..self:concat(", ").."}"; end };
 
 local function new_array(self, t, _s, _var)
 	if type(t) == "function" then -- Assume iterator
@@ -35,7 +37,7 @@ setmetatable(array, { __call = new_array });
 
 -- Read-only methods
 function array_methods:random()
-	return self[math_random(1,#self)];
+	return self[math_random(1, #self)];
 end
 
 -- These methods can be called two ways:
@@ -43,7 +45,7 @@ end
 --   existing_array:method([params, ...]) -- Transform existing array into result
 --
 function array_base.map(outa, ina, func)
-	for k,v in ipairs(ina) do
+	for k, v in ipairs(ina) do
 		outa[k] = func(v);
 	end
 	return outa;
@@ -52,20 +54,20 @@ end
 function array_base.filter(outa, ina, func)
 	local inplace, start_length = ina == outa, #ina;
 	local write = 1;
-	for read=1,start_length do
+	for read = 1, start_length do
 		local v = ina[read];
 		if func(v) then
 			outa[write] = v;
 			write = write + 1;
 		end
 	end
-	
+
 	if inplace and write <= start_length then
-		for i=write,start_length do
+		for i = write, start_length do
 			outa[i] = nil;
 		end
 	end
-	
+
 	return outa;
 end
 
@@ -78,35 +80,45 @@ function array_base.sort(outa, ina, ...)
 end
 
 function array_base.pluck(outa, ina, key)
-	for i=1,#ina do
+	for i = 1, #ina do
 		outa[i] = ina[i][key];
 	end
 	return outa;
 end
 
---- These methods only mutate the array
-function array_methods:shuffle(outa, ina)
-	local len = #self;
-	for i=1,#self do
-		local r = math_random(i,len);
-		self[i], self[r] = self[r], self[i];
+function array_base.reverse(outa, ina)
+	local len = #ina;
+	if ina == outa then
+		local middle = math_floor(len/2);
+		len = len + 1;
+		local o; -- opposite
+		for i = 1, middle do
+			o = len - i;
+			outa[i], outa[o] = outa[o], outa[i];
+		end
+	else
+		local off = len + 1;
+		for i = 1, len do
+			outa[i] = ina[off - i];
+		end
 	end
-	return self;
+	return outa;
 end
 
-function array_methods:reverse()
-	local len = #self-1;
-	for i=len,1,-1 do
-		self:push(self[i]);
-		self:pop(i);
+--- These methods only mutate the array
+function array_methods:shuffle()
+	local len = #self;
+	for i = 1, #self do
+		local r = math_random(i, len);
+		self[i], self[r] = self[r], self[i];
 	end
 	return self;
 end
 
-function array_methods:append(array)
-	local len,len2  = #self, #array;
-	for i=1,len2 do
-		self[len+i] = array[i];
+function array_methods:append(ina)
+	local len, len2 = #self, #ina;
+	for i = 1, len2 do
+		self[len+i] = ina[i];
 	end
 	return self;
 end
@@ -116,11 +128,7 @@ function array_methods:push(x)
 	return self;
 end
 
-function array_methods:pop(x)
-	local v = self[x];
-	t_remove(self, x);
-	return v;
-end
+array_methods.pop = t_remove;
 
 function array_methods:concat(sep)
 	return t_concat(array.map(self, tostring), sep);
@@ -135,7 +143,7 @@ function array.collect(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 setmetatable(t, array_mt);
@@ -157,7 +165,4 @@ for method, f in pairs(array_base) do
 	end
 end
 
-_G.array = array;
-module("array");
-
 return array;