vararg.lua

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

print('testing vararg')

function f(a, ...)
  local x = {n = select('#', ...), ...}
  for i = 1, x.n do assert(a[i] == x[i]) end
  return x.n
end

function c12 (...)
  assert(arg == _G.arg)    -- no local 'arg'
  local x = {...}; x.n = #x
  local res = (x.n==2 and x[1] == 1 and x[2] == 2)
  if res then res = 55 end
  return res, 2
end

function vararg (...) return {n = select('#', ...), ...} end

local call = function (f, args) return f(table.unpack(args, 1, args.n)) end

assert(f() == 0)
assert(f({1,2,3}, 1, 2, 3) == 3)
assert(f({"alo", nil, 45, f, nil}, "alo", nil, 45, f, nil) == 5)

assert(vararg().n == 0)
assert(vararg(nil, nil).n == 2)

assert(c12(1,2)==55)
a,b = assert(call(c12, {1,2}))
assert(a == 55 and b == 2)
a = call(c12, {1,2;n=2})
assert(a == 55 and b == 2)
a = call(c12, {1,2;n=1})
assert(not a)
assert(c12(1,2,3) == false)
local a = vararg(call(next, {_G,nil;n=2}))
local b,c = next(_G)
assert(a[1] == b and a[2] == c and a.n == 2)
a = vararg(call(call, {c12, {1,2}}))
assert(a.n == 2 and a[1] == 55 and a[2] == 2)
a = call(print, {'+'})
assert(a == nil)

local t = {1, 10}
function t:f (...) local arg = {...}; return self[...]+#arg end
assert(t:f(1,4) == 3 and t:f(2) == 11)
print('+')

lim = 20
local i, a = 1, {}
while i <= lim do a[i] = i+0.3; i=i+1 end

function f(a, b, c, d, ...)
  local more = {...}
  assert(a == 1.3 and more[1] == 5.3 and
         more[lim-4] == lim+0.3 and not more[lim-3])
end

function g(a,b,c)
  assert(a == 1.3 and b == 2.3 and c == 3.3)
end

call(f, a)
call(g, a)

a = {}
i = 1
while i <= lim do a[i] = i; i=i+1 end
assert(call(math.max, a) == lim)

print("+")


-- new-style varargs

function oneless (a, ...) return ... end

function f (n, a, ...)
  local b
  assert(arg == _G.arg)   -- no local 'arg'
  if n == 0 then
    local b, c, d = ...
    return a, b, c, d, oneless(oneless(oneless(...)))
  else
    n, b, a = n-1, ..., a
    assert(b == ...)
    return f(n, a, ...)
  end
end

a,b,c,d,e = assert(f(10,5,4,3,2,1))
assert(a==5 and b==4 and c==3 and d==2 and e==1)

a,b,c,d,e = f(4)
assert(a==nil and b==nil and c==nil and d==nil and e==nil)


-- varargs for main chunks
f = load[[ return {...} ]]
x = f(2,3)
assert(x[1] == 2 and x[2] == 3 and x[3] == undef)


f = load[[
  local x = {...}
  for i=1,select('#', ...) do assert(x[i] == select(i, ...)) end
  assert(x[select('#', ...)+1] == undef)
  return true
]]

assert(f("a", "b", nil, {}, assert))
assert(f())

a = {select(3, table.unpack{10,20,30,40})}
assert(#a == 2 and a[1] == 30 and a[2] == 40)
a = {select(1)}
assert(next(a) == nil)
a = {select(-1, 3, 5, 7)}
assert(a[1] == 7 and a[2] == undef)
a = {select(-2, 3, 5, 7)}
assert(a[1] == 5 and a[2] == 7 and a[3] == undef)
pcall(select, 10000)
pcall(select, -10000)


-- bug in 5.2.2

function f(p1, p2, p3, p4, p5, p6, p7, p8, p9, p10,
p11, p12, p13, p14, p15, p16, p17, p18, p19, p20,
p21, p22, p23, p24, p25, p26, p27, p28, p29, p30,
p31, p32, p33, p34, p35, p36, p37, p38, p39, p40,
p41, p42, p43, p44, p45, p46, p48, p49, p50, ...)
  local a1,a2,a3,a4,a5,a6,a7
  local a8,a9,a10,a11,a12,a13,a14
end

-- assertion fail here
f()

-- missing arguments in tail call
do
  local function f(a,b,c) return c, b end
  local function g() return f(1,2) end
  local a, b = g()
  assert(a == nil and b == 2)
end
print('OK')