mod_admin_telnet: Don't rely on getpeerchain returning an empty list

[prosody.git] / util / array.lua

diff --git a/util/array.lua b/util/array.lua
index 11ff651caf95c61fc79dc53fd0100ebea6e1d23a..2d58e7fb72d623169faa0deeada3dac881154462 100644 (file)
--- a/util/array.lua
+++ b/util/array.lua
@@ -1,58 +1,109 @@
+-- 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.
+--
+
+local t_insert, t_sort, t_remove, t_concat
+    = table.insert, table.sort, table.remove, table.concat;
+
+local setmetatable = setmetatable;
+local math_random = math.random;
+local pairs, ipairs = pairs, ipairs;
+local tostring = tostring;
+
 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, __tostring = function (array) return array:concat(", "); end };
-local function new_array(_, t)
+local function new_array(self, t, _s, _var)
+       if type(t) == "function" then -- Assume iterator
+               t = self.collect(t, _s, _var);
+       end
        return setmetatable(t or {}, array_mt);
 end
 
+function array_mt.__add(a1, a2)
+       local res = new_array();
+       return res:append(a1):append(a2);
+end
+
 setmetatable(array, { __call = new_array });
 
-function array:map(func, t2)
-       local t2 = t2 or array{};
-       for k,v in ipairs(self) do
-               t2[k] = func(v);
+-- Read-only methods
+function array_methods:random()
+       return self[math_random(1,#self)];
+end
+
+-- These methods can be called two ways:
+--   array.method(existing_array, [params [, ...]]) -- Create new array for result
+--   existing_array:method([params, ...]) -- Transform existing array into result
+--
+function array_base.map(outa, ina, func)
+       for k,v in ipairs(ina) do
+               outa[k] = func(v);
        end
-       return t2;
+       return outa;
 end
 
-function array:filter(func, t2)
-       local t2 = t2 or array{};
-       for k,v in ipairs(self) do
+function array_base.filter(outa, ina, func)
+       local inplace, start_length = ina == outa, #ina;
+       local write = 1;
+       for read=1,start_length do
+               local v = ina[read];
                if func(v) then
-                       t2:push(v);
+                       outa[write] = v;
+                       write = write + 1;
                end
        end
-       return t2;
+       
+       if inplace and write <= start_length then
+               for i=write,start_length do
+                       outa[i] = nil;
+               end
+       end
+       
+       return outa;
 end
 
+function array_base.sort(outa, ina, ...)
+       if ina ~= outa then
+               outa:append(ina);
+       end
+       t_sort(outa, ...);
+       return outa;
+end
 
-array.push = table.insert;
-array.pop = table.remove;
-array.sort = table.sort;
-array.concat = table.concat;
-array.length = function (t) return #t; end
-
-function array:random()
-       return self[math.random(1,#self)];
+function array_base.pluck(outa, ina, key)
+       for i=1,#ina do
+               outa[i] = ina[i][key];
+       end
+       return outa;
 end
 
-function array:shuffle()
+--- 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);
+               local r = math_random(i,len);
                self[i], self[r] = self[r], self[i];
        end
+       return self;
 end
 
-function array:reverse()
+function array_methods:reverse()
        local len = #self-1;
        for i=len,1,-1 do
                self:push(self[i]);
                self:pop(i);
        end
+       return self;
 end
 
-function array:append(array)
+function array_methods:append(array)
        local len,len2  = #self, #array;
        for i=1,len2 do
                self[len+i] = array[i];
@@ -60,16 +111,52 @@ function array:append(array)
        return self;
 end
 
+function array_methods:push(x)
+       t_insert(self, x);
+       return self;
+end
+
+function array_methods:pop(x)
+       local v = self[x];
+       t_remove(self, x);
+       return v;
+end
+
+function array_methods:concat(sep)
+       return t_concat(array.map(self, tostring), sep);
+end
+
+function array_methods:length()
+       return #self;
+end
+
+--- These methods always create a new array
 function array.collect(f, s, var)
-       local t, var = {};
+       local t = {};
        while true do
                var = f(s, var);
                if var == nil then break; end
-               table.insert(t, var);
+               t_insert(t, var);
        end
        return setmetatable(t, array_mt);
 end
 
+---
+
+-- Setup methods from array_base
+for method, f in pairs(array_base) do
+       local base_method = f;
+       -- Setup global array method which makes new array
+       array[method] = function (old_a, ...)
+               local a = new_array();
+               return base_method(a, old_a, ...);
+       end
+       -- Setup per-array (mutating) method
+       array_methods[method] = function (self, ...)
+               return base_method(self, self, ...);
+       end
+end
+
 _G.array = array;
 module("array");