local function assert_eq(actual, expected, message)
  if actual ~= expected then
    error('Assertion failed: ' .. message)
  end
end

local function assertThrows(msg_substr, fn)
  local ok, err = pcall(fn)

  if ok then
    error('Assertion failed: expected error containing "'
      .. msg_substr .. '"')
  end

  if type(err) ~= 'string' then
    err = tostring(err)
  end

  if not string.find(err, msg_substr, 1, true) then
    error('Assertion failed: expected error message to contain "'
      .. msg_substr .. '", got: "' .. err .. '"')
  end
end

-- 1. Integer vs float zero divisors

-- 1.1. Integer zeros collapse (no -0 for integers)
assert_eq(1/0 == 1/-0, true, 'int: 1/0 == 1/-0 (+Inf)')
assert_eq(-1/0 == 1/-0, false, 'int: -1/0 != 1/-0')

-- 1.2. Float zeros sign preservation
assert_eq(1/0.0 == 1/-0.0, false, 'float: +Inf != -Inf')
assert_eq(1/0.0 == -1/-0.0, true, 'float: 1/0.0 == -1/-0.0')
assert_eq(-1/0.0 == 1/-0.0, true, 'float: -1/0.0 == 1/-0.0')

-- 1.3. Basic division
assert_eq(5/2, 2.5, 'div: 5/2 == 2.5')
assert_eq(-5/2, -2.5, 'div: -5/2 == -2.5')
assert_eq(5/-2, -2.5, 'div: 5/-2 == -2.5')
assert_eq(-5/-2, 2.5, 'div: -5/-2 == 2.5')

-- 2. Unary minus literals and simple expressions
assert_eq(1/-(0) == 1/0, true, 'unary minus: int literal (+Inf)')
assert_eq(1/-(0.0) == -1/0.0, true, 'unary minus: float literal (-Inf)')
assert_eq(1/-(1-1) == 1/0, true, 'unary minus: int expr (+Inf)')
assert_eq(1/-(1.0-1.0) == -1/0.0, true, 'unary minus: float expr (-Inf)')

-- 2.1. Unary minus coercion and precedence with power
assert_eq(-2^2, -4, 'precedence: -2^2 == -(2^2)')
assert_eq((-2)^2, 4, 'precedence: (-2)^2 == 4')

-- 3. Integer operations (must not produce -0)
assert_eq(1/(1-1) == 1/0, true, 'int: sub (+0)')
assert_eq(1/(0*-1) == 1/0, true, 'int: mul (+0)')
assert_eq(1/(0%1) == 1/0, true, 'int: mod (+0)')
assert_eq(1/(0%-1) == 1/0, true, 'int: mod neg divisor (+0)')

-- 4. Float operations (must preserve -0.0)
assert_eq(1/(0.0*-1.0) == -1/ 0.0, true, 'float: mul (-0.0)')
assert_eq(1/((-0.0)%1.0) == -1/ 0.0, true, 'float: mod (-0.0)')
assert_eq(1/((-0.0)%-1.0) == -1/ 0.0, true, 'float: mod neg divisor (-0.0)')

-- 4.1. Zero result from float addition prefers +0.0
assert_eq(1/((-0.0)+0.0) == 1/0.0, true, 'float: (-0.0)+0.0 yields +0.0')

-- 4.2. Plain -0.0 handling in arithmetic
do
  local nz = -0.0
  -- Addition: -0.0 + 0 yields +0.0 (IEEE 754 rule)
  assert_eq(1/(nz + 0), 1/0.0, 'plain -0.0: nz + 0 yields +0.0')
  assert_eq(1/(0 + nz), 1/0.0, 'plain -0.0: 0 + nz yields +0.0')

  -- Multiplication preserves -0.0
  assert_eq(1/(nz * 1), -1/0.0, 'plain -0.0: nz * 1 yields -0.0')
  assert_eq(1/(1 * nz), -1/0.0, 'plain -0.0: 1 * nz yields -0.0')

  -- Subtraction: -0.0 - 0 = -0.0
  assert_eq(1/(nz - 0), 1/0.0, 'plain -0.0: nz - 0 yields +0.0')

  -- Subtraction: -0.0 - 0.0 = -0.0 (float)
  assert_eq(1/(nz - 0.0), -1/0.0, 'plain -0.0: nz - 0.0 yields -0.0')

  -- Subtraction: 0 - (-0.0) = +0.0
  assert_eq(1/(0 - nz), 1/0.0, 'plain -0.0: 0 - nz yields +0.0')
end

-- 4.3. Expression-generated -0.0
do
  local r = 0.0 * -1.0
  assert_eq(1/r, -1/0.0, 'expr: 0.0 * -1.0 yields -0.0')

  local s = -1.0 * 0.0
  assert_eq(1/s, -1/0.0, 'expr: -1.0 * 0.0 yields -0.0')

  -- Division producing -0.0
  local d = -0.0 / 1.0
  assert_eq(1/d, -1/0.0, 'expr: -0.0 / 1.0 yields -0.0')
end

-- 5. Mixed arithmetic producing zero
assert_eq(1/(0*-1.0) == -1/0.0, true, 'mixed: mul int*float (-0.0)')
assert_eq(1/(0.0*-1 ) == -1/0.0, true, 'mixed: mul float*int (-0.0)')
assert_eq(1/(1.0+(-1)) == 1/0.0, true, 'mixed: add (+0.0)')
assert_eq(1/(-(1-1.0)) == -1/0.0, true, 'mixed: sub then unary minus (-0.0)')

-- 6. Variables
local zi, zf, zfn = 0, 0.0, -0.0

assert_eq(1/zi == 1/0, true, 'var: zi (+Inf)')
assert_eq(1/zf == 1/0.0, true, 'var: zf (+Inf)')
assert_eq(1/zfn == -1/0.0, true, 'var: zfn (-Inf)')
assert_eq(1/-(zi) == 1/0, true, 'var: unary minus zi (+Inf)')
assert_eq(1/-(zfn) == 1/0.0, true, 'var: unary minus zfn (+Inf)')

-- 7. Functions returning zeros and unary minus
local function ret_zi()
  return 0
end

local function ret_zf()
  return 0.0
end

local function ret_zfn()
  return -0.0
end

assert_eq(1/ret_zi() == 1/0, true, 'fn: ret_zi (+Inf)')
assert_eq(1/ret_zf() == 1/0.0, true, 'fn: ret_zf (+Inf)')
assert_eq(1/ret_zfn() == -1/0.0, true, 'fn: ret_zfn (-Inf)')

assert_eq(1/-(ret_zi()) == 1/0, true, 'fn unary minus: ret_zi (+Inf)')
assert_eq(1/-(ret_zf()) == -1/0.0, true, 'fn unary minus: ret_zf (-Inf)')
assert_eq(1/-(ret_zfn()) == 1/0.0, true, 'fn unary minus: ret_zfn (+Inf)')

-- 8. Tables and arrays
local t, arr = {zi=zi, zfn=zfn}, {zi, zfn}

-- 8.1. Tables
assert_eq(1/t.zi == 1/0, true, 'table: t.zi (+Inf)')
assert_eq(1/t.zfn == -1/0.0, true, 'table: t.zfn (-Inf)')

-- 8.2. Arrays
assert_eq(1/arr[1] == 1/0, true, 'array: arr[1]=zi (+Inf)')
assert_eq(1/arr[2] == -1/0.0, true, 'array: arr[2]=zfn (-Inf)')

-- 9. Deeply nested parentheses and expressions
local xi, xf = 1-1, 1.0-1.0
local deepi = -((((0+0)-(1-1))+(zi-xi))) -- int path (+0)
local deepf = -((((0.0+0.0)-(1.0-1.0))+(zf-xf))) -- float path (-0.0)

assert_eq(1/deepi == 1/0, true, 'nested: int (+Inf)')
assert_eq(1/deepf == -1/0.0, true, 'nested: float (-Inf)')

-- 10. Floor division near zero
assert_eq(1/(0//1) == 1/0, true, 'floor div: int (+0)')
assert_eq(1/(0.0//1.0) == 1/0.0, true, 'floor div: float (+Inf)')
assert_eq(1/((-0.0)//1.0) == -1/0.0, true, 'floor div: float (-Inf)')
assert_eq(1/(0//1.0) == 1/0.0, true, 'floor div: mixed (+0.0)')

-- 10.1. Modulo/division identity
local function id_ok(a, b)
  return a == b * (a // b) + a % b
end

assert_eq(id_ok(5, 2), true, 'identity: 5, 2')
assert_eq(id_ok(-5, 2), true, 'identity: -5, 2')
assert_eq(id_ok(5, -2), true, 'identity: 5, -2')
assert_eq(id_ok(-5, -2), true, 'identity: -5, -2')

-- 10.2. Floor division signs
assert_eq(5//-2, -3, 'idiv: 5//-2 == -3')
assert_eq(-5//2, -3, 'idiv: -5//2 == -3')
assert_eq(-5//-2, 2, 'idiv: -5//-2 == 2')

-- 11. Ordering and NaN
assert_eq((-0.0) < (0.0), false, 'ordering: -0.0 < 0.0 is false')
assert_eq((0.0) < (-0.0), false, 'ordering: 0.0 < -0.0 is false')
assert_eq((-0.0) <= (0.0), true, 'ordering: -0.0 <= 0.0')
assert_eq((0.0) <= (-0.0), true, 'ordering: 0.0 <= -0.0')
assert_eq((0/0) == (0/0), false, 'NaN: never equals itself')

-- 12. Bitwise operators
assert_eq((~0) == -1, true, 'bitwise not on int ok')

val = pcall(
  function()
    return ~0.0
  end
)
assert_eq(val, true, 'bitwise not on float ok')

val = pcall(
  function()
    return 0<<1
  end
)
assert_eq(val, true, 'shl int ok')

val = pcall(
  function()
    return 0.0<<1
  end
)
assert_eq(val, true, 'shl float ok')

-- 12.1 Bitwise ops results
assert_eq((5&3) == 1, true, 'bitwise and result')
assert_eq((5|2) == 7, true, 'bitwise or result')
assert_eq((5~1) == 4, true, 'bitwise xor result')
assert_eq((1<<5) == 32, true, 'bitwise shl result')
assert_eq((32>>5) == 1, true, 'bitwise shr result')

-- 12.2 Bitwise with float values
assert_eq((~(-0.0)) == -1, true, 'bitwise not on -0.0 == -1')

-- 13. Evaluation order (left-to-right) for binary ops
local log, val

-- arithmetic + - * /
local function lhs_num()
  log[#log + 1] = 'L'
  return 1
end

local function rhs_num()
  log[#log + 1] = 'R'
  return 2
end

log = {}
val = lhs_num()+rhs_num()
assert_eq(table.concat(log, ''), 'LR', 'order: +')

log = {}
val = lhs_num()-rhs_num()
assert_eq(table.concat(log, ''), 'LR', 'order: -')

log = {}
val = lhs_num()*rhs_num()
assert_eq(table.concat(log, ''), 'LR', 'order: *')

log = {}
val = lhs_num()/rhs_num()
assert_eq(table.concat(log, ''), 'LR', 'order: /')

-- floor div and mod
log = {}
val = lhs_num()//rhs_num()
assert_eq(table.concat(log, ''), 'LR', 'order: //')

log = {}
val = lhs_num()%rhs_num()
assert_eq(table.concat(log, ''), 'LR', 'order: %')

-- power and concatenation
log = {}
val = lhs_num()^rhs_num()
assert_eq(table.concat(log, ''), 'LR', 'order: ^')

local function lhs_str()
  log[#log + 1] = 'L'
  return 'a'
end

local function rhs_str()
  log[#log + 1] = 'R'
  return 'b'
end

log = {}
val = lhs_str()..rhs_str()
assert_eq(table.concat(log, ''), 'LR', 'order: ..')

-- relational
log = {}
val = (lhs_num() < rhs_num())
assert_eq(table.concat(log, ''), 'LR', 'order: <')

log = {}
val = (lhs_num() <= rhs_num())
assert_eq(table.concat(log, ''), 'LR', 'order: <=')

log = {}
val = (lhs_num() > rhs_num())
assert_eq(table.concat(log, ''), 'LR', 'order: >')

log = {}
val = (lhs_num() >= rhs_num())
assert_eq(table.concat(log, ''), 'LR', 'order: >=')

log = {}
val = (lhs_num() == rhs_num())
assert_eq(table.concat(log, ''), 'LR', 'order: ==')

log = {}
val = (lhs_num() ~= rhs_num())
assert_eq(table.concat(log, ''), 'LR', 'order: ~=')

-- bitwise
log = {}
val = lhs_num()&rhs_num()
assert_eq(table.concat(log, ''), 'LR', 'order: &')

log = {}
val = lhs_num()|rhs_num()
assert_eq(table.concat(log, ''), 'LR', 'order: |')

log = {}
val = lhs_num()~rhs_num()
assert_eq(table.concat(log, ''), 'LR', 'order: ~ (xor)')

log = {}
val = lhs_num()<<rhs_num()
assert_eq(table.concat(log, ''), 'LR', 'order: <<')

log = {}
val = lhs_num()>>rhs_num()
assert_eq(table.concat(log, ''), 'LR', 'order: >>')

-- 13.2. Nested expressions and associativity
local function exp_a()
  log[#log + 1] = 'A'
  return 2
end

local function exp_b()
  log[#log + 1] = 'B'
  return 3
end

local function exp_c()
  log[#log + 1] = 'C'
  return 2
end

log = {}
val = exp_a() ^ (exp_b() ^ exp_c())
assert_eq(val, 512, 'nested expression result')
assert_eq(table.concat(log, ''), 'ABC', 'nested expression associativity')

assert_eq(2^3^2, 512, 'power associativity')

-- 14. String-to-number coercion around zero
assert_eq(1/('0') == 1/0.0, true, 'str: ("0") (+Inf)')
assert_eq(1/('-0') == 1/0.0, true, 'str: ("-0") (+Inf)')
assert_eq(1/('0.0') == 1/0.0, true, 'str: ("0.0") (+Inf)')
assert_eq(1/('-0.0') == -1/0.0, true, 'str: ("-0.0") (-Inf)')
assert_eq(1/-('0') == 1/0.0, true, 'str: unary minus -("0") (+Inf)')
assert_eq(1/-('-0') == 1/0.0, true, 'str: unary minus -("-0") (+Inf)')

-- 14.1. General arithmetic with numeric strings
assert_eq('1'+2, 3, 'str-num: "1"+2 == 3')
assert_eq(' -2 ' * '3', -6, 'str-num: " -2 " * "3" == -6')
assert_eq('0x10' + 1, 17, 'str-num: hex int string + 1 == 17')
assert_eq('0x1p4' + 0, 16, 'str-num: hex float string + 0 == 16')
assertThrows("attempt to add a 'string' with a 'number'",
  function()
    return 'x1'+1
  end
)

-- 15. Recursive function producing int zero (and unary minus)
local function rec_zero(n)
  if n == 0 then
    return 0
  end
  return -rec_zero(n - 1)
end

assert_eq(1/rec_zero(5) == 1/0, true, 'recursive: rec_zero (+Inf)')
assert_eq(1/(rec_zero(5)) == 1/0, true, 'recursive: (rec_zero) (+Inf)')
assert_eq(1/-(rec_zero(5)) == 1/0, true, 'recursive: -(rec_zero) (+Inf)')
assert_eq(1/-rec_zero(5) == 1/0, true, 'recursive: -(rec_zero) (+Inf)')

-- 16. Modulo and integer division by zero

-- 16.1. Modulo by zero
assertThrows("attempt to perform 'n%0'",
  function()
    return 1%0
  end
)

val = pcall(
  function()
    return 1.0%0.0
  end
)
assert_eq(val, true, 'float mod by zero ok (NaN)')

val = pcall(
  function()
    return 1.0%0
  end
)
assert_eq(val, true, 'mixed (float,int) mod by zero ok (NaN)')

val = pcall(
  function()
    return 1%0.0
  end
)
assert_eq(val, true, 'mixed (int,float) mod by zero ok (NaN)')

-- 16.2. Integer division by zero
assertThrows('divide by zero',
  function()
    return 1//0
  end
)

val = pcall(
  function()
    return 1.0//0.0
  end
)
assert_eq(val, true, 'float idiv by zero ok (+Inf/-Inf)')

val = pcall(
  function()
    return 1.0//0
  end
)
assert_eq(val, true, 'mixed (float,int) idiv by zero ok (+Inf/-Inf)')

val = pcall(
  function()
    return 1//0.0
  end
)
assert_eq(val, true, 'mixed (int,float) idiv by zero ok (+Inf/-Inf)')

-- 16.3. Modulo sign semantics (explicit)
assert_eq(5 % -2, -1, 'mod: 5 % -2 == -1')
assert_eq(-5 % 2, 1, 'mod: -5 % 2 == 1')
assert_eq(-5 % -2, -1, 'mod: -5 % -2 == -1')

-- 17. Metamethod precedence: __add should dispatch
local mt = {
  __add = function(_, _)
    return 'added'
  end
}
local tbl = setmetatable({}, mt)

assert_eq(tbl + tbl, 'added', '__add dispatched')

-- 17.1 Unary metamethod: __unm (negation)
local mt_unm = {
  __unm = function(_)
    return 'negated'
  end
}
local u = setmetatable({}, mt_unm)

assert_eq(-u, 'negated', '__unm dispatched')

-- 17.2 Unary metamethod: __bnot (bitwise NOT)
local bnot_calls = 0
local mt_bnot = {
  __bnot = function(_)
    bnot_calls = bnot_calls + 1
    return 123
  end
}
local b = setmetatable({}, mt_bnot)

assert_eq(~b, 123, '__bnot dispatched')
assert_eq(bnot_calls, 1, '__bnot called exactly once')

-- 17.3. Unary metamethods multi-return (first return only)
local mt_unm_mr = {
  __unm = function(_)
    return 7, 8
  end
}
local um = setmetatable({}, mt_unm_mr)

assert_eq(-um, 7, '__unm uses first return value')

local mt_bnot_mr = {
  __bnot = function(_)
    return 9, 10
  end
}
local bm = setmetatable({}, mt_bnot_mr)

assert_eq(~bm, 9, '__bnot uses first return value')

-- 18. Multi-return in arithmetic (first return only)
local function multi_ret()
  return 0, 1
end

assert_eq(1/(multi_ret()) == 1/0, true, 'multi-ret: 1st used (+Inf)')
assert_eq(1/-(multi_ret()) == 1/0, true, 'multi-ret: unary minus 1st used (+Inf)')

-- 18.1 Exponentiation zero edge cases
assert_eq(0^0 == 1, true, 'pow: 0^0 == 1')
assert_eq((-0.0)^0 == 1, true, 'pow: (-0.0)^0 == 1')

-- 19. Error tests
assertThrows('has no integer representation',
  function()
    return ~0.5
  end
)

assertThrows("attempt to add a 'string' with a 'number'",
  function()
    return 'a'+1
  end
)

assertThrows('attempt to perform arithmetic on a table value',
  function()
    return -{}
  end
)

-- 19.1. Bitwise on non-integers should error
assertThrows('has no integer representation',
  function()
    return 1.5&1
  end
)

assertThrows(
  "attempt to perform bitwise operation on a string value (constant '3')",
  function()
    return '3'|1
  end
)

assertThrows('has no integer representation',
  function()
    return 1~1.2
  end
)

assertThrows('has no integer representation',
  function()
    return 1<<0.1
  end
)

-- 19.2. Relational type error
assertThrows('attempt to compare number with string',
  function()
    return 1<'1'
  end
)

-- 19.3. Additional negative tests
assertThrows('attempt to perform arithmetic on a table value',
  function()
    return 1+{}
  end
)

assertThrows("attempt to unm a 'string' with a 'string'",
  function()
    return -'x'
  end
)

assertThrows(
  "attempt to perform bitwise operation on a string value (constant '1')",
  function()
    return ~'1'
  end
)

assertThrows('attempt to compare string with number',
  function()
    return '1'<1
  end
)

assertThrows('attempt to compare number with table',
  function()
    return 1<{}
  end
)

-- 19.4. String arithmetic: exact verb mapping
assertThrows("attempt to sub a 'string' with a 'number'",
  function()
    return 'x' - 1
  end
)

assertThrows("attempt to mul a 'string' with a 'number'",
  function()
    return 'x' * 2
  end
)

assertThrows("attempt to div a 'string' with a 'number'",
  function()
    return 'x' / 2
  end
)

assertThrows("attempt to idiv a 'string' with a 'number'",
  function()
    return 'x' // 2
  end
)

assertThrows("attempt to mod a 'string' with a 'number'",
  function()
    return 'x' % 2
  end
)

assertThrows("attempt to pow a 'string' with a 'number'",
  function()
    return 'x' ^ 2
  end
)

-- 19.4.1. String arithmetic: type pairing and string-vs-string cases
assertThrows("attempt to add a 'string' with a 'string'",
  function()
    return 'x' + 'y'
  end
)

assertThrows("attempt to mul a 'number' with a 'string'",
  function()
    return 2 * 'x'
  end
)

-- 19.5. Bitwise: exact type errors
assertThrows("attempt to perform bitwise operation on a table value",
  function()
    return {} & 1
  end
)

assertThrows("attempt to perform bitwise operation on a nil value",
  function()
    return nil | 1
  end
)

assertThrows("attempt to perform bitwise operation on a boolean value",
  function()
    return true ~ 1
  end
)

-- 19.6. Bitwise shifts: non-integer RHS
assertThrows("number has no integer representation",
  function()
    return 1 << 0.5
  end
)

assertThrows("number has no integer representation",
  function()
    return 8 >> 0.25
  end
)

-- 19.7. Concatenation: exact messages
assertThrows("attempt to concatenate a nil value",
  function()
    return nil .. "x"
  end
)

assertThrows("attempt to concatenate a nil value",
  function()
    return "x" .. nil
  end
)

assertThrows("attempt to concatenate a table value",
  function()
    return "x" .. {}
  end
)

-- 19.8. Length operator: exact message
assertThrows("attempt to get length of a number value",
  function()
    return #1
  end
)

assertThrows("attempt to get length of a nil value",
  function()
    return #nil
  end
)

-- 19.9. Relational mismatches
assertThrows("attempt to compare number with string",
  function()
    return 1 <= '1'
  end
)

assertThrows("attempt to compare number with string",
  function()
    return '1' >= 1
  end
)

assertThrows("attempt to compare table with number",
  function()
    return 1 > {}
  end
)

assertThrows("attempt to compare table with number",
  function()
    return {} < 1
  end
)

-- 19.10. Explicit int-path division/modulo by zero through expr
assertThrows("attempt to perform 'n%0'",
  function()
    return 1 % (1-1)
  end
)

assertThrows("attempt to divide by zero",
  function()
    return 1 // (1-1)
  end
)

-- 20. `tostring()` numeric formatting

-- 20.1. Integers
assert_eq(tostring(0), '0', 'tostring: 0')
assert_eq(tostring(1), '1', 'tostring: 1')
assert_eq(tostring(-5), '-5', 'tostring: -5')
assert_eq(tostring(42), '42', 'tostring: 42')
assert_eq(tostring(-123), '-123', 'tostring: -123')

-- 20.2. Float zeros (positive and negative)
assert_eq(tostring(0.0), '0.0', 'tostring: 0.0')
assert_eq(tostring(-0.0), '-0.0', 'tostring: -0.0')

-- 20.3. Integer-valued floats
assert_eq(tostring(1.0), '1.0', 'tostring: 1.0')
assert_eq(tostring(2.0), '2.0', 'tostring: 2.0')
assert_eq(tostring(-3.0), '-3.0', 'tostring: -3.0')
assert_eq(tostring(100.0), '100.0', 'tostring: 100.0')

-- 20.4. Non-integer floats
assert_eq(tostring(0.5), '0.5', 'tostring: 0.5')
assert_eq(tostring(3.14), '3.14', 'tostring: 3.14')
assert_eq(tostring(-2.5), '-2.5', 'tostring: -2.5')

-- 20.5. Special float values
assert_eq(tostring(1/0.0), 'inf', 'tostring: +inf')
assert_eq(tostring(-1/0.0), '-inf', 'tostring: -inf')
assert_eq(tostring(0.0/0.0), '-nan', 'tostring: NaN')
assert_eq(tostring(1.0%0.0), '-nan', 'tostring: NaN from modulo')
assert_eq(tostring((-1.0)%0.0), '-nan', 'tostring: NaN from neg modulo')

-- 20.6. Results from tonumber() preserve type
assert_eq(tostring(tonumber('5')), '5', 'tonumber int: "5"')
assert_eq(tostring(tonumber('5.')), '5.0', 'tonumber float: "5."')
assert_eq(tostring(tonumber('.5')), '0.5', 'tonumber float: ".5"')
assert_eq(tostring(tonumber('5.0')), '5.0', 'tonumber float: "5.0"')
assert_eq(tostring(tonumber('0x10')), '16', 'tonumber hex int: "0x10"')
assert_eq(tostring(tonumber('0x10.0')), '16.0', 'tonumber hex float: "0x10.0"')
assert_eq(tostring(tonumber('0x1p4')), '16.0', 'tonumber hex float: "0x1p4"')

-- 20.7. Arithmetic results formatting
assert_eq(tostring(1+1), '2', 'int+int yields int')
assert_eq(tostring(1.0+1.0), '2.0', 'float+float yields float')
assert_eq(tostring(1+1.0), '2.0', 'int+float yields float')
assert_eq(tostring(5/2), '2.5', 'division yields float')
assert_eq(tostring(4/2), '2.0', 'division exact yields float')

-- 21. Numeric for loops: comprehensive type/mode coverage

-- 21.1. Integer mode (all params integer-valued and untagged)

do
  local types, vals = {}, {}
  for i = 1, 3 do
    table.insert(types, math.type(i))
    table.insert(vals, tostring(i))
  end
  assert_eq(table.concat(types, ','), 'integer,integer,integer', 'for 1,3: types')
  assert_eq(table.concat(vals, ','), '1,2,3', 'for 1,3: values')
end

do
  local types = {}
  for i = 1, 3, 1 do
    table.insert(types, math.type(i))
  end
  assert_eq(types[1], 'integer', 'for 1,3,1: type')
end

do
  local vals = {}
  for i = 3, 1, -1 do
    table.insert(vals, tostring(i))
  end
  assert_eq(table.concat(vals, ','), '3,2,1', 'for 3,1,-1: descending')
end

do
  local found_zero = false
  local zero_str
  for i = -1, 1 do
    if i == 0 then
      found_zero = true
      zero_str = tostring(i)
    end
  end
  assert_eq(found_zero, true, 'for -1,1: crosses zero')
  assert_eq(zero_str, '0', 'for -1,1: zero is int')
end

do
  for i = 1, 3 do
    local zero = i - i
    assert_eq(math.type(zero), 'integer', 'for 1,3: i-i is int')
    assert_eq(tostring(zero), '0', 'for 1,3: i-i formats as int')
  end
end

do
  for i = 2, 4 do
    local expr = i * 2 - i - i
    assert_eq(math.type(expr), 'integer', 'for 2,4: int expr is int')
    assert_eq(expr, 0, 'for 2,4: int expr value')
  end
end

-- 21.2. Float mode (all params float-typed)

do
  local types, vals = {}, {}
  for i = 1.0, 3.0, 1.0 do
    table.insert(types, math.type(i))
    table.insert(vals, tostring(i))
  end
  assert_eq(table.concat(types, ','), 'float,float,float', 'for 1.0,3.0,1.0: types')
  assert_eq(table.concat(vals, ','), '1.0,2.0,3.0', 'for 1.0,3.0,1.0: values')
end

do
  local vals = {}
  for i = 0.5, 2.5, 0.5 do
    table.insert(vals, tostring(i))
  end
  assert_eq(table.concat(vals, ','), '0.5,1.0,1.5,2.0,2.5', 'for 0.5,2.5,0.5: values')
end

do
  local vals = {}
  for i = 3.0, 1.0, -1.0 do
    table.insert(vals, tostring(i))
  end
  assert_eq(table.concat(vals, ','), '3.0,2.0,1.0', 'for 3.0,1.0,-1.0: descending')
end

do
  local vals = {}
  for i = 2.5, 0.5, -0.5 do
    table.insert(vals, tostring(i))
  end
  assert_eq(table.concat(vals, ','), '2.5,2.0,1.5,1.0,0.5', 'for 2.5,0.5,-0.5: values')
end

do
  local zero_str
  for i = -1.0, 1.0 do
    if i == 0 then
      zero_str = tostring(i)
    end
  end
  assert_eq(zero_str, '0.0', 'for -1.0,1.0: zero is float')
end

do
  for i = 1.0, 3.0 do
    local zero = i - i
    assert_eq(math.type(zero), 'float', 'for 1.0,3.0: i-i is float')
    assert_eq(tostring(zero), '0.0', 'for 1.0,3.0: i-i formats as float')
  end
end

do
  for i = 2.0, 4.0 do
    local expr = i * 2.0 - i - i
    assert_eq(math.type(expr), 'float', 'for 2.0,4.0: float expr is float')
    assert_eq(tostring(expr), '0.0', 'for 2.0,4.0: float expr formats')
  end
end

-- 21.3. Mixed mode (start type determines loop var type)

do
  local types, vals = {}, {}
  for i = 1, 3.5 do
    table.insert(types, math.type(i))
    table.insert(vals, tostring(i))
  end
  assert_eq(types[1], 'integer', 'for 1,3.5: start int yields var int')
  assert_eq(types[2], 'integer', 'for 1,3.5: var stays int')
  assert_eq(table.concat(vals, ','), '1,2,3', 'for 1,3.5: int formatting')
end

do
  local types, vals = {}, {}
  for i = 1.0, 3 do
    table.insert(types, math.type(i))
    table.insert(vals, tostring(i))
  end
  assert_eq(types[1], 'float', 'for 1.0,3: start float yields var float')
  assert_eq(types[2], 'float', 'for 1.0,3: var stays float')
  assert_eq(table.concat(vals, ','), '1.0,2.0,3.0', 'for 1.0,3: float formatting')
end

do
  local types = {}
  for i = 1, 3.0 do
    table.insert(types, math.type(i))
  end
  assert_eq(types[1], 'integer', 'for 1,3.0: end=3.0 but start int yields var int')
end

do
  local types, vals = {}, {}
  for i = 1, 3, 1.0 do
    table.insert(types, math.type(i))
    table.insert(vals, tostring(i))
  end
  assert_eq(types[1], 'float', 'for 1,3,1.0: step float yields var float')
  assert_eq(table.concat(vals, ','), '1.0,2.0,3.0', 'for 1,3,1.0: float formatting')
end

do
  local types, vals = {}, {}
  for i = 1.0, 3.0, 1 do
    table.insert(types, math.type(i))
    table.insert(vals, tostring(i))
  end
  assert_eq(types[1], 'float', 'for 1.0,3.0,1: start float yields var float')
  assert_eq(table.concat(vals, ','), '1.0,2.0,3.0', 'for 1.0,3.0,1: float formatting')
end

do
  local types = {}
  for i = 3.0, 1, -1 do
    table.insert(types, math.type(i))
  end
  assert_eq(types[1], 'float', 'for 3.0,1,-1: start float yields var float')
end

-- Mixed mode: float step, integer start
do
  local types, vals = {}, {}
  for i = 1, 3, 1.0 do
    table.insert(types, math.type(i))
    table.insert(vals, tostring(i))
  end
  assert_eq(types[1], 'float', 'for 1,3,1.0: step float yields var float')
  assert_eq(table.concat(vals, ','), '1.0,2.0,3.0', 'for 1,3,1.0: float formatting')
end

-- Mixed mode: integer start, negative float step
do
  local types, vals = {}, {}
  for i = 3, 1, -1.0 do
    table.insert(types, math.type(i))
    table.insert(vals, tostring(i))
  end
  assert_eq(types[1], 'float', 'for 3,1,-1.0: step float yields var float')
  assert_eq(table.concat(vals, ','), '3.0,2.0,1.0', 'for 3,1,-1.0: float formatting')
end

do
  for i = 1, 3.5 do
    local zero = i - i
    assert_eq(math.type(zero), 'integer', 'for 1,3.5: start int yields i-i is int')
  end
end

do
  for i = 1.0, 3 do
    local zero = i - i
    assert_eq(math.type(zero), 'float', 'for 1.0,3: start float yields i-i is float')
  end
end

-- 21.4. Boundary conditions

do
  local count = 0
  for i = 5, 5 do
    count = count + 1
    assert_eq(i, 5, 'for 5,5: i=5')
  end
  assert_eq(count, 1, 'for 5,5: one iteration')
end

do
  local count = 0
  for i = 5, 3 do
    count = count + 1
  end
  assert_eq(count, 0, 'for 5,3: no iterations')
end

do
  local count = 0
  for i = 3, 5, -1 do
    count = count + 1
  end
  assert_eq(count, 0, 'for 3,5,-1: no iterations')
end

do
  local last
  for i = 1.0, 3.0 do
    last = i
  end
  assert_eq(tostring(last), '3.0', 'for 1.0,3.0: exactly reaches end')
end

do
  local last
  for i = 1, 10, 3 do
    last = i
  end
  assert_eq(last, 10, 'for 1,10,3: reaches end exactly')
end

do
  local last
  for i = 1, 9, 3 do
    last = i
  end
  assert_eq(last, 7, 'for 1,9,3: stops before end')
end

do
  local vals = {}
  for i = 0.1, 0.3, 0.1 do
    table.insert(vals, i)
  end
  assert_eq(#vals, 2, 'for 0.1,0.3,0.1: small float step iterations')
end

do
  local vals = {}
  -- 0.5 has exact binary representation
  for i = 0.5, 1.5, 0.5 do
    table.insert(vals, i)
  end
  assert_eq(#vals, 3, 'for 0.5,1.5,0.5: small float step')
end

-- 21.5. Edge cases and errors

assertThrows('step is zero', function()
  for i = 1, 10, 0 do
  end
end)

assertThrows('step is zero', function()
  for i = 1.0, 10.0, 0.0 do
  end
end)

do
  local count = 0
  for i = 1, 1000000 do
    count = count + 1
    if count > 5 then break end
  end
  assert_eq(count, 6, 'for 1,1000000: large range with break')
end

do
  local sum = 0
  for i = 1, 5, 2 do
    sum = sum + i
  end
  assert_eq(sum, 9, 'for 1,5,2: step>1 sum (1+3+5)')
end

do
  local sum = 0
  for i = 10, 1, -3 do
    sum = sum + i
  end
  assert_eq(sum, 22, 'for 10,1,-3: negative step>1 sum (10+7+4+1)')
end

-- 22. Table numeric key equivalence

-- 22.1. Integer-valued floats normalize to integers

do
  local t = {}
  t[1] = 'one'
  assert_eq(t[1.0], 'one', 'table: t[1] accessed via t[1.0]')
  assert_eq(t[1], 'one', 'table: t[1] accessed via t[1]')
end

do
  local t = {}
  t[2.0] = 'two'
  assert_eq(t[2], 'two', 'table: t[2.0] accessed via t[2]')
  assert_eq(t[2.0], 'two', 'table: t[2.0] accessed via t[2.0]')
end

do
  local t = {}
  t[1] = 'a'
  t[2.0] = 'b'
  t[3] = 'c'
  assert_eq(t[1.0], 'a', 'table: multi-key t[1.0]')
  assert_eq(t[2], 'b', 'table: multi-key t[2]')
  assert_eq(t[3.0], 'c', 'table: multi-key t[3.0]')
end

do
  local t = {}
  t[5] = 'first'
  t[5.0] = 'second'
  assert_eq(t[5], 'second', 'table: overwrite int with float')
  assert_eq(t[5.0], 'second', 'table: overwrite int with float (access)')
end

do
  local t = {}
  t[100] = 'hundred'
  assert_eq(t[100.0], 'hundred', 'table: large int t[100.0]')
end

-- 22.2. Zero normalization (both -0 and +0 map to same key)

do
  local t = {}
  t[0] = 'zero'
  assert_eq(t[-0.0], 'zero', 'table: t[0] accessed via t[-0.0]')
  assert_eq(t[0.0], 'zero', 'table: t[0] accessed via t[0.0]')
  assert_eq(t[0], 'zero', 'table: t[0] accessed via t[0]')
end

do
  local t = {}
  t[-0.0] = 'negzero'
  assert_eq(t[0], 'negzero', 'table: t[-0.0] accessed via t[0]')
  assert_eq(t[0.0], 'negzero', 'table: t[-0.0] accessed via t[0.0]')
  assert_eq(t[-0.0], 'negzero', 'table: t[-0.0] accessed via t[-0.0]')
end

do
  local t = {}
  t[0.0] = 'float_zero'
  assert_eq(t[0], 'float_zero', 'table: t[0.0] accessed via t[0]')
  assert_eq(t[-0.0], 'float_zero', 'table: t[0.0] accessed via t[-0.0]')
end

do
  local t = {}
  t[0] = 'first'
  t[-0.0] = 'second'
  t[0.0] = 'third'
  assert_eq(t[0], 'third', 'table: zero overwrite final')
  assert_eq(t[-0.0], 'third', 'table: zero overwrite via -0.0')
end

-- 22.3. Non-integer floats are distinct keys

do
  local t = {}
  t[1] = 'int_one'
  t[1.5] = 'one_point_five'
  assert_eq(t[1], 'int_one', 'table: non-int float t[1]')
  assert_eq(t[1.5], 'one_point_five', 'table: non-int float t[1.5]')
  assert_eq(t[1.0], 'int_one', 'table: non-int float t[1.0] maps to int')
end

do
  local t = {}
  t[0.5] = 'half'
  t[1.5] = 'one_half'
  t[2.5] = 'two_half'
  assert_eq(t[0.5], 'half', 'table: multi non-int t[0.5]')
  assert_eq(t[1.5], 'one_half', 'table: multi non-int t[1.5]')
  assert_eq(t[2.5], 'two_half', 'table: multi non-int t[2.5]')
end

-- 22.4. Mixed integer and float keys

do
  local t = {}
  t[0] = 'zero'
  t[1] = 'one'
  t[1.5] = 'one_point_five'
  t[2.0] = 'two'
  t[-0.0] = 'neg_zero'

  assert_eq(t[0], 'neg_zero', 'table: mixed t[0] (last zero)')
  assert_eq(t[0.0], 'neg_zero', 'table: mixed t[0.0]')
  assert_eq(t[-0.0], 'neg_zero', 'table: mixed t[-0.0]')
  assert_eq(t[1], 'one', 'table: mixed t[1]')
  assert_eq(t[1.0], 'one', 'table: mixed t[1.0]')
  assert_eq(t[1.5], 'one_point_five', 'table: mixed t[1.5]')
  assert_eq(t[2], 'two', 'table: mixed t[2]')
  assert_eq(t[2.0], 'two', 'table: mixed t[2.0]')
end

-- 22.5. Key equivalence with expressions

do
  local t = {}
  t[1+1] = 'two'
  assert_eq(t[2.0], 'two', 'table: expr key t[1+1] via t[2.0]')
  assert_eq(t[4/2], 'two', 'table: expr key t[4/2]')
end

do
  local t = {}
  t[1-1] = 'int_zero'
  assert_eq(t[0], 'int_zero', 'table: expr t[1-1] via t[0]')
  assert_eq(t[0.0], 'int_zero', 'table: expr t[1-1] via t[0.0]')
  assert_eq(t[-0.0], 'int_zero', 'table: expr t[1-1] via t[-0.0]')
end

do
  local t = {}
  t[1.0-1.0] = 'float_zero'
  assert_eq(t[0], 'float_zero', 'table: expr t[1.0-1.0] via t[0]')
  assert_eq(t[-0.0], 'float_zero', 'table: expr t[1.0-1.0] via t[-0.0]')
end

-- 22.6. Key equivalence with variables

do
  local t = {}
  local i = 1
  local f = 1.0
  t[i] = 'from_int'
  assert_eq(t[f], 'from_int', 'table: var int key via float var')
end

do
  local t = {}
  local i = 1
  local f = 1.0
  t[f] = 'from_float'
  assert_eq(t[i], 'from_float', 'table: var float key via int var')
end

do
  local t = {}
  local zi = 0
  local zf = 0.0
  local zfn = -0.0
  t[zi] = 'int_zero'
  assert_eq(t[zf], 'int_zero', 'table: var zi via zf')
  assert_eq(t[zfn], 'int_zero', 'table: var zi via zfn')
end

-- 22.7. Key equivalence in array part

do
  local t = {10, 20, 30}
  assert_eq(t[1.0], 10, 'table: array t[1.0]')
  assert_eq(t[2.0], 20, 'table: array t[2.0]')
  assert_eq(t[3.0], 30, 'table: array t[3.0]')
end

do
  local t = {}
  t[1.0] = 'first'
  t[2.0] = 'second'
  assert_eq(t[1], 'first', 'table: array assign t[1.0] via t[1]')
  assert_eq(t[2], 'second', 'table: array assign t[2.0] via t[2]')
end

-- 22.8. Key counting and iteration

do
  local t = {}
  t[1] = 'a'
  t[1.0] = 'b'
  t[2] = 'c'
  t[2.0] = 'd'

  local count = 0
  for k, v in pairs(t) do
    count = count + 1
  end
  assert_eq(count, 2, 'table: normalized keys count as one')
end

do
  local t = {}
  t[0] = 'a'
  t[0.0] = 'b'
  t[-0.0] = 'c'

  local count = 0
  for k, v in pairs(t) do
    count = count + 1
  end
  assert_eq(count, 1, 'table: all zeros count as one key')
end

-- 23. Type introspection: type() and math.type()

-- 23.1. Basic type() function (returns general Lua types)

assert_eq(type(nil), 'nil', 'type(nil)')
assert_eq(type(true), 'boolean', 'type(true)')
assert_eq(type(false), 'boolean', 'type(false)')
assert_eq(type(0), 'number', 'type(0) is number')
assert_eq(type(1), 'number', 'type(1) is number')
assert_eq(type(0.0), 'number', 'type(0.0) is number')
assert_eq(type(1.0), 'number', 'type(1.0) is number')
assert_eq(type(-0.0), 'number', 'type(-0.0) is number')
assert_eq(type(1.5), 'number', 'type(1.5) is number')
assert_eq(type(1/0.0), 'number', 'type(inf) is number')
assert_eq(type(0.0/0.0), 'number', 'type(nan) is number')
assert_eq(type('hello'), 'string', 'type(string)')
assert_eq(type({}), 'table', 'type(table)')
assert_eq(type(function() end), 'function', 'type(function)')

-- 23.2. math.type() function (distinguishes integer vs float)

-- Integers
assert_eq(math.type(0), 'integer', 'math.type(0)')
assert_eq(math.type(1), 'integer', 'math.type(1)')
assert_eq(math.type(-1), 'integer', 'math.type(-1)')
assert_eq(math.type(42), 'integer', 'math.type(42)')
assert_eq(math.type(-123), 'integer', 'math.type(-123)')
assert_eq(math.type(1000000), 'integer', 'math.type(1000000)')

-- Floats (literals with decimal point)
assert_eq(math.type(0.0), 'float', 'math.type(0.0)')
assert_eq(math.type(-0.0), 'float', 'math.type(-0.0)')
assert_eq(math.type(1.0), 'float', 'math.type(1.0)')
assert_eq(math.type(2.0), 'float', 'math.type(2.0)')
assert_eq(math.type(-3.0), 'float', 'math.type(-3.0)')
assert_eq(math.type(100.0), 'float', 'math.type(100.0)')

-- Floats (non-integer values)
assert_eq(math.type(0.5), 'float', 'math.type(0.5)')
assert_eq(math.type(1.5), 'float', 'math.type(1.5)')
assert_eq(math.type(3.14), 'float', 'math.type(3.14)')
assert_eq(math.type(-2.5), 'float', 'math.type(-2.5)')

-- Special float values
assert_eq(math.type(1/0.0), 'float', 'math.type(inf)')
assert_eq(math.type(-1/0.0), 'float', 'math.type(-inf)')
assert_eq(math.type(0.0/0.0), 'float', 'math.type(nan)')

-- Non-numbers return nil
assert_eq(math.type(nil), nil, 'math.type(nil) yields nil')
assert_eq(math.type(true), nil, 'math.type(boolean) yields nil')
assert_eq(math.type('123'), nil, 'math.type(string) yields nil')
assert_eq(math.type({}), nil, 'math.type(table) yields nil')
assert_eq(math.type(function() end), nil, 'math.type(function) yields nil')

-- 23.3. Integer arithmetic preserves integer type

do
  local a = 1
  local b = 2
  assert_eq(math.type(a + b), 'integer', 'int + int yields integer')
  assert_eq(math.type(a - b), 'integer', 'int - int yields integer')
  assert_eq(math.type(a * b), 'integer', 'int * int yields integer')
  assert_eq(math.type(a // b), 'integer', 'int // int yields integer')
  assert_eq(math.type(a % b), 'integer', 'int % int yields integer')
end

-- Integer operations producing zero
do
  assert_eq(math.type(1 - 1), 'integer', '1 - 1 yields integer zero')
  assert_eq(math.type(0 * 5), 'integer', '0 * 5 yields integer zero')
  assert_eq(math.type(0 % 1), 'integer', '0 % 1 yields integer zero')
  assert_eq(math.type(0 // 1), 'integer', '0 // 1 yields integer zero')
end

-- 23.4. Float arithmetic preserves float type

do
  local a = 1.0
  local b = 2.0
  assert_eq(math.type(a + b), 'float', 'float + float yields float')
  assert_eq(math.type(a - b), 'float', 'float - float yields float')
  assert_eq(math.type(a * b), 'float', 'float * float yields float')
  assert_eq(math.type(a / b), 'float', 'float / float yields float')
  assert_eq(math.type(a // b), 'float', 'float // float yields float')
  assert_eq(math.type(a % b), 'float', 'float % float yields float')
end

-- Float operations producing zero
do
  assert_eq(math.type(1.0 - 1.0), 'float', '1.0 - 1.0 yields float zero')
  assert_eq(math.type(0.0 * 5.0), 'float', '0.0 * 5.0 yields float zero')
  assert_eq(math.type(0.0 % 1.0), 'float', '0.0 % 1.0 yields float zero')
  assert_eq(math.type(0.0 // 1.0), 'float', '0.0 // 1.0 yields float zero')
end

-- 23.5. Mixed arithmetic promotes to float

do
  assert_eq(math.type(1 + 1.0), 'float', 'int + float yields float')
  assert_eq(math.type(1.0 + 1), 'float', 'float + int yields float')
  assert_eq(math.type(2 * 1.5), 'float', 'int * float yields float')
  assert_eq(math.type(3.0 - 1), 'float', 'float - int yields float')
  assert_eq(math.type(5 // 2.0), 'float', 'int // float yields float')
  assert_eq(math.type(5.0 % 2), 'float', 'float % int yields float')
end

-- Mixed operations producing zero
do
  assert_eq(math.type(1 - 1.0), 'float', '1 - 1.0 yields float zero')
  assert_eq(math.type(0 * 1.0), 'float', '0 * 1.0 yields float zero')
  assert_eq(math.type(0.0 * 1), 'float', '0.0 * 1 yields float zero')
end

-- 23.6. Division and power always produce floats

do
  assert_eq(math.type(4 / 2), 'float', '4 / 2 yields float (2.0)')
  assert_eq(math.type(5 / 2), 'float', '5 / 2 yields float (2.5)')
  assert_eq(math.type(1 / 1), 'float', '1 / 1 yields float (1.0)')

  assert_eq(math.type(2 ^ 3), 'float', '2 ^ 3 yields float (8.0)')
  assert_eq(math.type(2 ^ 0), 'float', '2 ^ 0 yields float (1.0)')
  assert_eq(math.type(10 ^ 2), 'float', '10 ^ 2 yields float (100.0)')
end

-- Division producing zero
do
  assert_eq(math.type(0 / 1), 'float', '0 / 1 yields float zero')
  assert_eq(math.type(0.0 / 1.0), 'float', '0.0 / 1.0 yields float zero')
end

-- 23.7. Unary minus preserves type

do
  assert_eq(math.type(-5), 'integer', '-5 is integer')
  assert_eq(math.type(-0), 'integer', '-0 is integer')

  assert_eq(math.type(-5.0), 'float', '-5.0 is float')
  assert_eq(math.type(-0.0), 'float', '-0.0 is float')
end

-- Unary minus on variables
do
  local i = 5
  local f = 5.0
  assert_eq(math.type(-i), 'integer', 'unary minus int var')
  assert_eq(math.type(-f), 'float', 'unary minus float var')
end

-- Unary minus on expressions
do
  assert_eq(math.type(-(1 + 1)), 'integer', 'unary minus int expr')
  assert_eq(math.type(-(1.0 + 1.0)), 'float', 'unary minus float expr')
end

-- 23.8. String coercion preserves type (tonumber)

do
  assert_eq(math.type(tonumber('5')), 'integer', 'tonumber("5") yields integer')
  assert_eq(math.type(tonumber('5.')), 'float', 'tonumber("5.") yields float')
  assert_eq(math.type(tonumber('.5')), 'float', 'tonumber(".5") yields float')
  assert_eq(math.type(tonumber('5.0')), 'float', 'tonumber("5.0") yields float')
  assert_eq(math.type(tonumber('-0')), 'integer', 'tonumber("-0") yields integer')
  assert_eq(math.type(tonumber('-0.0')), 'float', 'tonumber("-0.0") yields float')
end

-- Hexadecimal literals
do
  assert_eq(math.type(tonumber('0x10')), 'integer', 'tonumber("0x10") yields integer')
  assert_eq(math.type(tonumber('0x10.0')), 'float', 'tonumber("0x10.0") yields float')
  assert_eq(math.type(tonumber('0x1p4')), 'float', 'tonumber("0x1p4") yields float')
end

-- 23.9. Variables preserve type through assignment

do
  local i = 5
  local f = 5.0

  assert_eq(math.type(i), 'integer', 'int variable')
  assert_eq(math.type(f), 'float', 'float variable')

  local i2 = i
  local f2 = f

  assert_eq(math.type(i2), 'integer', 'int variable copy')
  assert_eq(math.type(f2), 'float', 'float variable copy')
end

-- 23.10. Function returns preserve type

do
  local function ret_int()
    return 42
  end

  local function ret_float()
    return 42.0
  end

  assert_eq(math.type(ret_int()), 'integer', 'function returns integer')
  assert_eq(math.type(ret_float()), 'float', 'function returns float')
end

-- 23.11. Table values preserve type

do
  local t = {
    i = 10,
    f = 10.0,
    [1] = 20,
    [2] = 20.0
  }

  assert_eq(math.type(t.i), 'integer', 'table int value (string key)')
  assert_eq(math.type(t.f), 'float', 'table float value (string key)')
  assert_eq(math.type(t[1]), 'integer', 'table int value (int key)')
  assert_eq(math.type(t[2]), 'float', 'table float value (int key)')
end

-- 23.12. For-loop variable type tracking

do
  -- Integer loop
  for i = 1, 3 do
    assert_eq(math.type(i), 'integer', 'for 1,3: var is integer')
    break  -- Just test first iteration
  end

  -- Float loop (start is float)
  for i = 1.0, 3 do
    assert_eq(math.type(i), 'float', 'for 1.0,3: var is float')
    break
  end

  -- Float loop (step is float)
  for i = 1, 3, 1.0 do
    assert_eq(math.type(i), 'float', 'for 1,3,1.0: var is float')
    break
  end
end

-- 23.13. Bitwise operations require integers (input & output)

do
  assert_eq(math.type(5 & 3), 'integer', 'bitwise and yields integer')
  assert_eq(math.type(5 | 2), 'integer', 'bitwise or yields integer')
  assert_eq(math.type(5 ~ 1), 'integer', 'bitwise xor yields integer')
  assert_eq(math.type(1 << 5), 'integer', 'left shift yields integer')
  assert_eq(math.type(32 >> 2), 'integer', 'right shift yields integer')
  assert_eq(math.type(~0), 'integer', 'bitwise not yields integer')
end

-- Bitwise operations convert float operands to integer
do
  assert_eq(math.type(5.0 & 3), 'integer', 'float & int yields integer')
  assert_eq(math.type(5 | 2.0), 'integer', 'int | float yields integer')
  assert_eq(math.type(5.0 ~ 1.0), 'integer', 'float ~ float yields integer')
end

-- 23.14. Edge cases: zero types

do
  -- Positive integer zero
  assert_eq(math.type(0), 'integer', '0 is integer')
  assert_eq(math.type(1 - 1), 'integer', '1 - 1 is integer')
  assert_eq(math.type(0 * 1), 'integer', '0 * 1 is integer')

  -- Positive float zero
  assert_eq(math.type(0.0), 'float', '0.0 is float')
  assert_eq(math.type(1.0 - 1.0), 'float', '1.0 - 1.0 is float')

  -- Negative float zero
  assert_eq(math.type(-0.0), 'float', '-0.0 is float')
  assert_eq(math.type(0.0 * -1.0), 'float', '0.0 * -1.0 is float')

  -- Integer operations never produce -0
  assert_eq(math.type(0 * -1), 'integer', '0 * -1 is integer (not -0)')
end

-- 23.15. Special float values

do
  local inf = 1.0 / 0.0
  local neginf = -1.0 / 0.0
  local nan = 0.0 / 0.0

  assert_eq(type(inf), 'number', 'inf has type number')
  assert_eq(type(neginf), 'number', '-inf has type number')
  assert_eq(type(nan), 'number', 'nan has type number')

  assert_eq(math.type(inf), 'float', 'inf has math.type float')
  assert_eq(math.type(neginf), 'float', '-inf has math.type float')
  assert_eq(math.type(nan), 'float', 'nan has math.type float')
end

-- 23.16. Type consistency across operations

do
  local i = 10
  local sum_i = 0

  for n = 1, 5 do
    sum_i = sum_i + n
    assert_eq(math.type(sum_i), 'integer', 'integer sum stays integer')
  end

  local f = 10.0
  local sum_f = 0.0

  for n = 1.0, 5.0 do
    sum_f = sum_f + n
    assert_eq(math.type(sum_f), 'float', 'float sum stays float')
  end
end