-- $Id: closure.lua,v 1.59 2016/11/07 13:11:28 roberto Exp $
-- 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 x + a + _ENV end end
assert(a[3] == a[4] and a[4] == a[5])
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])
local function f()
return function (x) return math.sin(_ENV[x]) end
end
assert(f() == f())
-- 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] == nil)
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 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
goto L1
error'not here'
::L1::
local y = 1
a[i] = function (x) local t = y; y = x; return t end
elseif i % 3 == 2 then
local t
goto l4
::l4a:: a[i] = t; goto l4b
error("should never be here!")
::l4::
local y = 2
t = function (x) local t = y; y = x; return t end
goto l4a
error("should never be here!")
::l4b::
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 pcall(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'
