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-rw-r--r--util/array.lua80
1 files changed, 59 insertions, 21 deletions
diff --git a/util/array.lua b/util/array.lua
index ce5ce077..686f55b1 100644
--- a/util/array.lua
+++ b/util/array.lua
@@ -6,9 +6,14 @@
-- 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 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)
return setmetatable(t or {}, array_mt);
end
@@ -20,36 +25,47 @@ 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);
+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
+
+ if inplace and write <= start_length then
+ for i=write,start_length do
+ outa[i] = nil;
end
end
- return t2;
+
+ 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()
+--- These methods only mutate
+function array_methods:random()
return self[math.random(1,#self)];
end
-function array:shuffle()
+function array_methods:shuffle(outa, ina)
local len = #self;
for i=1,#self do
local r = math.random(i,len);
@@ -58,7 +74,7 @@ function array:shuffle()
return self;
end
-function array:reverse()
+function array_methods:reverse()
local len = #self-1;
for i=len,1,-1 do
self:push(self[i]);
@@ -67,7 +83,7 @@ function array:reverse()
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];
@@ -75,6 +91,12 @@ function array:append(array)
return self;
end
+array_methods.push = table.insert;
+array_methods.pop = table.remove;
+array_methods.concat = table.concat;
+array_methods.length = function (t) return #t; end
+
+--- These methods always create a new array
function array.collect(f, s, var)
local t, var = {};
while true do
@@ -85,6 +107,22 @@ function array.collect(f, s, var)
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");