prosody/util/array.lua

-- Prosody IM
-- Copyright (C) 2008-2009 Matthew Wild
-- Copyright (C) 2008-2009 Waqas Hussain
-- 
-- This project is MIT/X11 licensed. Please see the
-- COPYING file in the source package for more information.
--

local array = {};

local array_mt = { __index = array, __tostring = function (array) return array:concat(", "); end };
local function new_array(_, t)
	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);
	end
	return t2;
end

function array:filter(func, t2)
	local t2 = t2 or array{};
	for k,v in ipairs(self) do
		if func(v) then
			t2:push(v);
		end
	end
	return t2;
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)];
end

function array: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: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)
	local len,len2  = #self, #array;
	for i=1,len2 do
		self[len+i] = array[i];
	end
	return self;
end

function array.collect(f, s, var)
	local t, var = {};
	while true do
		var = f(s, var);
	        if var == nil then break; end
		table.insert(t, var);
	end
	return setmetatable(t, array_mt);
end

_G.array = array;
module("array");

return array;