-- $Id: testes/closure.lua $
-- See Copyright Notice in file all.lua

print "testing closures"

local A, B = 0, { g = 10 }
function f(x)
  local a = {}
  for i = 1, 1000 do
    local y = 0
    do
      a[i] = function()
        B.g = B.g + 1; y = y + x; return y + A
      end
    end
  end
  local dummy = function() return a[A] end
  collectgarbage()
  A = 1; assert(dummy() == a[1]); A = 0;
  assert(a[1]() == x)
  assert(a[3]() == x)
  collectgarbage()
  assert(B.g == 12)
  return a
end

local a = f(10)
-- force a GC in this level
local x = { [1] = {} }       -- to detect a GC
setmetatable(x, { __mode = 'kv' })
while x[1] do                -- repeat until GC
  local a = A .. A .. A .. A -- create garbage
  A = A + 1
end
assert(a[1]() == 20 + A)
assert(a[1]() == 30 + A)
assert(a[2]() == 10 + A)
collectgarbage()
assert(a[2]() == 20 + A)
assert(a[2]() == 30 + A)
assert(a[3]() == 20 + A)
assert(a[8]() == 10 + A)
assert(getmetatable(x).__mode == 'kv')
assert(B.g == 19)


-- testing equality
a = {}

for i = 1, 5 do a[i] = function(x) return i + a + _ENV end end
assert(a[3] ~= a[4] and a[4] ~= a[5])

do
  local a = function(x) return math.sin(_ENV[x]) end
  local function f()
    return a
  end
  assert(f() == f())
end


-- testing closures with 'for' control variable
a = {}
for i = 1, 10 do
  a[i] = { set = function(x) i = x end, get = function() return i end }
  if i == 3 then break end
end
assert(a[4] == undef)
a[1].set(10)
assert(a[2].get() == 2)
a[2].set('a')
assert(a[3].get() == 3)
assert(a[2].get() == 'a')

a = {}
local t = { "a", "b" }
for i = 1, #t do
  local k = t[i]
  a[i] = {
    set = function(x, y)
      i = x; k = y
    end,
    get = function() return i, k end
  }
  if i == 2 then break end
end
a[1].set(10, 20)
local r, s = a[2].get()
assert(r == 2 and s == 'b')
r, s = a[1].get()
assert(r == 10 and s == 20)
a[2].set('a', 'b')
r, s = a[2].get()
assert(r == "a" and s == "b")


-- testing closures with 'for' control variable x break
for i = 1, 3 do
  f = function() return i end
  break
end
assert(f() == 1)

for k = 1, #t do
  local v = t[k]
  f = function() return k, v end
  break
end
assert(({ f() })[1] == 1)
assert(({ f() })[2] == "a")


-- testing closure x break x return x errors

local b
function f(x)
  local first = 1
  while 1 do
    if x == 3 and not first then return end
    local a = 'xuxu'
    b = function(op, y)
      if op == 'set' then
        a = x + y
      else
        return a
      end
    end
    if x == 1 then
      do break end
    elseif x == 2 then
      return
    else
      if x ~= 3 then error() end
    end
    first = nil
  end
end

for i = 1, 3 do
  f(i)
  assert(b('get') == 'xuxu')
  b('set', 10); assert(b('get') == 10 + i)
  b = nil
end

pcall(f, 4);
assert(b('get') == 'xuxu')
b('set', 10); assert(b('get') == 14)


local w
-- testing multi-level closure
function f(x)
  return function(y)
    return function(z) return w + x + y + z end
  end
end

y = f(10)
w = 1.345
assert(y(20)(30) == 60 + w)


-- testing closures x break
do
  local X, Y
  local a = math.sin(0)

  while a do
    local b = 10
    X = function() return b end -- closure with upvalue
    if a then break end
  end

  do
    local b = 20
    Y = function() return b end -- closure with upvalue
  end

  -- upvalues must be different
  assert(X() == 10 and Y() == 20)
end


-- testing closures x repeat-until

local a = {}
local i = 1
repeat
  local x = i
  a[i] = function()
    i = x + 1; return x
  end
until i > 10 or a[i]() ~= x
assert(i == 11 and a[1]() == 1 and a[3]() == 3 and i == 4)


-- testing closures created in 'then' and 'else' parts of 'if's
a = {}
for i = 1, 10 do
  if i % 3 == 0 then
    local y = 0
    a[i] = function(x)
      local t = y; y = x; return t
    end
  elseif i % 3 == 1 then
    error 'not here'

    local y = 1
    a[i] = function(x)
      local t = y; y = x; return t
    end
  elseif i % 3 == 2 then
    local t


    a[i] = t;
    error("should never be here!")

    local y = 2
    t = function(x)
      local t = y; y = x; return t
    end

    error("should never be here!")
  end
end

for i = 1, 10 do
  assert(a[i](i * 10) == i % 3 and a[i]() == i * 10)
end

print '+'


-- test for correctly closing upvalues in tail calls of vararg functions
local function t()
  local function c(a, b) assert(a == "test" and b == "OK") end
  local function v(f, ...) c("test", f() ~= 1 and "FAILED" or "OK") end
  local x = 1
  return v(function() return x end)
end
t()


-- test for debug manipulation of upvalues
local debug = require 'debug'

do
  local a, b, c = 3, 5, 7
  foo1 = function() return a + b end;
  foo2 = function() return b + a end;
  do
    local a = 10
    foo3 = function() return a + b end;
  end
end

assert(debug.upvalueid(foo1, 1))
assert(debug.upvalueid(foo1, 2))
assert(not debug.upvalueid(foo1, 3))
assert(debug.upvalueid(foo1, 1) == debug.upvalueid(foo2, 2))
assert(debug.upvalueid(foo1, 2) == debug.upvalueid(foo2, 1))
assert(debug.upvalueid(foo3, 1))
assert(debug.upvalueid(foo1, 1) ~= debug.upvalueid(foo3, 1))
assert(debug.upvalueid(foo1, 2) == debug.upvalueid(foo3, 2))

assert(debug.upvalueid(string.gmatch("x", "x"), 1) ~= nil)

assert(foo1() == 3 + 5 and foo2() == 5 + 3)
debug.upvaluejoin(foo1, 2, foo2, 2)
assert(foo1() == 3 + 3 and foo2() == 5 + 3)
assert(foo3() == 10 + 5)
debug.upvaluejoin(foo3, 2, foo2, 1)
assert(foo3() == 10 + 5)
debug.upvaluejoin(foo3, 2, foo2, 2)
assert(foo3() == 10 + 3)

assert(not pcall(debug.upvaluejoin, foo1, 3, foo2, 1))
assert(not pcall(debug.upvaluejoin, foo1, 1, foo2, 3))
assert(not pcall(debug.upvaluejoin, foo1, 0, foo2, 1))
assert(not pcall(debug.upvaluejoin, print, 1, foo2, 1))
assert(not pcall(debug.upvaluejoin, {}, 1, foo2, 1))
assert(not pcall(debug.upvaluejoin, foo1, 1, print, 1))

print 'OK'