vararg.lua

-- $Id: vararg.lua,v 1.25 2016/11/07 13:11:28 roberto Exp $
-- See Copyright Notice in file all.lua

print('testing vararg')

function f(a, ...)
  local arg = {n = select('#', ...), ...}
  for i=1,arg.n do assert(a[i]==arg[i]) end
  return arg.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(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
_USPACE[[
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)
]]
_KSPACE[[
local i, a = 1, {}
while i <= lim do a[i] = i+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+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
_USPACE[[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] == nil)


f = load[[
  local x = {...}
  for i=1,select('#', ...) do assert(x[i] == select(i, ...)) end
  assert(x[select('#', ...)+1] == nil)
  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] == nil)
a = {select(-2, 3, 5, 7)}
assert(a[1] == 5 and a[2] == 7 and a[3] == nil)
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()


print('OK')