Z>>Смесь луа и металуа ++ Автор отказался от минимализиа, но слегка увлекся в другую сторону, навалив туда все, о чем знал. Некоторые называют это "практический язык" . VM там от Lua, с незначительными (судя по результатам тестов) изменениями.

In the begenning of 2006, the author was attracted and convinced by the design of the Lua 5 virtual machine, and started to design and implement the Dao interpreter as a new virtual machine with ideas inspired by the Lua virtual machine and its instruction set. Since then the language has also been re-designed under the name Dao.

var tuple = [2,"second"];

var tuple = { num:2, name:"second"};

CS>var tuple = [2,"second"];
CS>

local x,y   = 1,2,3 -- correct in lua: 3 just gone
local x,y,z = 1,2   -- correct in lua: z == nil

CS>>var tuple = [2,"second"];
CS>>

Z>local x,y   = 1,2,3 -- correct in lua: 3 just gone
Z>local x,y,z = 1,2   -- correct in lua: z == nil 
Z>

local v = (1,2,3) 
local x,y,z = (1,2,3)

CS>local v = (1,2,3) 
CS>

CS>local x,y,z = (1,2,3)
CS>

local x,y,z = (1,2)

Z>Буду признателен за примеры борьбы посредством GC (за исключением очевидных: "перешли на Java/C#/Erlang" ).

CS>>local v = (1,2,3) 
CS>>

local x,y,z = 1,2,3

CS>>local x,y,z = (1,2,3)
CS>>

local x,y,z = (1,2,3)
x = y + z

Z>local x,y,z = (1,2)
Z>

return (x,y,z);

local x,y,z = get_3D_coordinate()

As you might imagine, given the size of our codebase, we do allocations from lots and lots of different places. Fortunately, there are several hot spots. Those include Javascript, strings, sqlite, CSS parsing, HTML parsing, and array growing. For some of these we don’t need to heap allocate and can just do temporary allocations on the stack. For others we can’t, but we can use arenas (as we already do for some layout objects) to help reduce fragmentation.

Z>>Буду признателен за примеры борьбы посредством GC (за исключением очевидных: "перешли на Java/C#/Erlang" ).

CS>local x,y,z = 1,2,3
CS>

CS>local x,y,z = (1,2,3)
CS>x = y + z
CS>

 -- компилятор переписывает это как:
local v$001 = (1,2,3)
local x = v$001._1
local y = v$001._2
local z = v$001._3

CS>return (x,y,z);
CS>

CS>local x,y,z = get_3D_coordinate()
CS>

$ scala
Welcome to Scala version 2.8.0.final (Java HotSpot(TM) Client VM, Java 1.6.0_13).
Type in expressions to have them evaluated.
Type :help for more information.

scala> val outer@(x,y) = (1,(2, 3))
outer: (Int, (Int, Int)) = (1,(2,3))
x: Int = 1
y: (Int, Int) = (2,3)

scala> outer
res0: (Int, (Int, Int)) = (1,(2,3))

scala> x
res1: Int = 1

scala> y
res2: (Int, Int) = (2,3)

scala>

Z>... на ней большие программы пишут, типа Adobе Lightroom

Z>>>Буду признателен за примеры борьбы посредством GC (за исключением очевидных: "перешли на Java/C#/Erlang" ).

CS>>local x,y,z = 1,2,3
CS>>

CS>>local x,y,z = (1,2,3)
CS>>x = y + z
CS>>

Z> -- компилятор переписывает это как:
Z>local v$001 = (1,2,3)
Z>local x = v$001._1
Z>local y = v$001._2
Z>local z = v$001._3
Z>

local x = 1
local y = 2
local z = 3

Z>$ scala
Z>Welcome to Scala version 2.8.0.final (Java HotSpot(TM) Client VM, Java 1.6.0_13).
Z>Type in expressions to have them evaluated.
Z>Type :help for more information.

scala>> val outer@(x,y) = (1,(2, 3))
Z>outer: (Int, (Int, Int)) = (1,(2,3))
Z>x: Int = 1
Z>y: (Int, Int) = (2,3)

scala>> outer
Z>res0: (Int, (Int, Int)) = (1,(2,3))

scala>> x
Z>res1: Int = 1

scala>> y
Z>res2: (Int, Int) = (2,3)

scala>>
Z>

Z>>... на ней большие программы пишут, типа Adobе Lightroom

http://en.wikipedia.org/wiki/Adobe_Photoshop_Lightroom
The new project was a deliberate departure from many of Adobe’s established conventions. 40% of Photoshop Lightroom is written using the Lua scripting language.

CS>Java, .NET, Lisp и его производные, м пр. все используют нормальный GC

CS>local x = 1
CS>local y = 2
CS>local z = 3
CS>

function a(x, y, ...)
    local z = x+y
    return b(z, ...) -- <- фигу
end

function a(x, y, ...)
    local z = x+y
    local args = {...}        -- <- pack stack to array
    return b(z, unpack(args)) -- <- unpack array to stack
end

Tuple<string,int> tp = Foo();
  string x = tp.Item1;
  int    y = tp.Item2;

-- проверка валидности

-- без PM
local result = null
local x,y = someFunction(somearg)
if (x != "tag001")
    throw "error"
else
    result = nextFun(y)
    
-- c PM
local "tag001", y = someFunction(somearg)
local result = nextFun(y)

-- fits :: (int,int,Cells) -> boolean
  -- @w - ribbon space left
  -- @k - current column
  -- Cells :: [{indent,Mode,Doc}]
  local function fits
    | w,_,_ if w < 0              -> false
    | _,_,[]                      -> true
    | w,k,{i,m,Empty}        :: z -> fits(w,k,z)
    | w,k,{i,m,`Cat{x,y}}    :: z -> fits(w,k,{i,m,x}::{i,m,y}::z)
    | w,k,{i,m,`Nest{j,x}}   :: z -> fits(w,k,{i+j,m,x}::z)
    | w,k,{i,m,`Text{s}}     :: z -> fits(w-#s,k+#s,z)
    | w,k,{i,FL,`Break{s}}   :: z -> fits(w-#s,k+#s,z)
    | w,k,{i,BR,`Break{_}}   :: z -> true
    | w,k,{i,m,`Group{x}}    :: z -> fits(w,k,{i,m,x}::z)
    | w,k,{i,m,`Column{f}}   :: z -> fits(w,k,{i,m,f(k)}::z)
    | w,k,{i,m,`Nesting{f}}  :: z -> fits(w,k,{i,m,f(i)}::z)
    | _,_,x -> error(tostring(x))
  end

[GC 325407K->83000K(776768K), 0.2300771 secs]
GC — Indicates that it was a minor collection (young generation). If it had said Full GC then that indicates that it was a major collection (tenured generation).
325407K — The combined size of live objects before garbage collection.
83000K — The combined size of live objects after garbage collection.
(776768K) — the total available space, not counting the space in the permanent generation, which is the total heap minus one of the survivor spaces.
0.2300771 secs — time it took for garbage collection to occur.