Voir la source de Module:table

--[[
------------------------------------------------------------------------------------
--                      table (formerly TableTools)                               --
--                                                                                --
-- This module includes a number of functions for dealing with Lua tables.        --
-- It is a meta-module, meant to be called from other Lua modules, and should     --
-- not be called directly from #invoke.                                           --
------------------------------------------------------------------------------------
--]]

--[[
	Inserting new values into a table using a local "index" variable, which is
	incremented each time, is faster than using "table.insert(t, x)" or
	"t[#t + 1] = x". See the talk page.
]]

local libraryUtil = require('libraryUtil')

local p = {}

-- Define often-used variables and functions.
local floor = math.floor
local infinity = math.huge
local checkType = libraryUtil.checkType
local checkTypeMulti = libraryUtil.checkTypeMulti

local function _check(funcName, expectType)
  if type(expectType) == "string" then
    return function(argIndex, arg, nilOk)
      checkType(funcName, argIndex, arg, expectType, nilOk)
    end
  else
    return function(argIndex, arg, expectType, nilOk)
      if type(expectType) == "table" then
        checkTypeMulti(funcName, argIndex, arg, expectType, nilOk)
      else
        checkType(funcName, argIndex, arg, expectType, nilOk)
      end
    end
  end
end

--[[
------------------------------------------------------------------------------------
-- isPositiveInteger
--
-- This function returns true if the given value is a positive integer, and false
-- if not. Although it doesn't operate on tables, it is included here as it is
-- useful for determining whether a given table key is in the array part or the
-- hash part of a table.
------------------------------------------------------------------------------------
--]]
function p.isPositiveInteger(v)
  if type(v) == 'number' and v >= 1 and floor(v) == v and v < infinity then
    return true
  else
    return false
  end
end

--[[
------------------------------------------------------------------------------------
-- isNan
--
-- This function returns true if the given number is a NaN value, and false
-- if not. Although it doesn't operate on tables, it is included here as it is
-- useful for determining whether a value can be a valid table key. Lua will
-- generate an error if a NaN is used as a table key.
------------------------------------------------------------------------------------
--]]
function p.isNan(v)
  if type(v) == 'number' and tostring(v) == '-nan' then
    return true
  else
    return false
  end
end

--[[
------------------------------------------------------------------------------------
-- shallowClone
--
-- This returns a clone of a table. The value returned is a new table, but all
-- subtables and functions are shared. Metamethods are respected, but the returned
-- table will have no metatable of its own.
------------------------------------------------------------------------------------
--]]
function p.shallowClone(t)
  local ret = {}
  for k, v in pairs(t) do
    ret[k] = v
  end
  return ret
end

--[[
Shallow copy
]]
function p.shallowcopy(orig)
  local orig_type = type(orig)
  local copy
  if orig_type == 'table' then
    copy = {}
    for orig_key, orig_value in pairs(orig) do
      copy[orig_key] = orig_value
    end
  else
    -- number, string, boolean, etc
    copy = orig
  end
  return copy
end

--[[
	Recursive deep copy function
	Equivalent to mw.clone?
]]
local function deepcopy(orig, includeMetatable, already_seen)
  -- Stores copies of tables indexed by the original table.
  already_seen = already_seen or {}

  local copy = already_seen[orig]
  if copy ~= nil then
    return copy
  end

  if type(orig) == 'table' then
    copy = {}
    for orig_key, orig_value in pairs(orig) do
      copy[deepcopy(orig_key, includeMetatable, already_seen)] = deepcopy(orig_value, includeMetatable, already_seen)
    end
    already_seen[orig] = copy

    if includeMetatable then
      local mt = getmetatable(orig)
      if mt ~= nil then
        local mt_copy = deepcopy(mt, includeMetatable, already_seen)
        setmetatable(copy, mt_copy)
        already_seen[mt] = mt_copy
      end
    end
  else
    -- number, string, boolean, etc
    copy = orig
  end
  return copy
end

function p.deepcopy(orig, noMetatable, already_seen)
  checkType("deepcopy", 3, already_seen, "table", true)

  return deepcopy(orig, not noMetatable, already_seen)
end

--[[
------------------------------------------------------------------------------------
-- removeDuplicates
--
-- This removes duplicate values from an array. Non-positive-integer keys are
-- ignored. The earliest value is kept, and all subsequent duplicate values are
-- removed, but otherwise the array order is unchanged.
------------------------------------------------------------------------------------
--]]
function p.removeDuplicates(t)
  checkType('removeDuplicates', 1, t, 'table')
  local isNan = p.isNan
  local ret, exists = {}, {}
  local index = 1
  for _, v in ipairs(t) do
    if isNan(v) then
      -- NaNs can't be table keys, and they are also unique, so we don't need to check existence.
      ret[index] = v
      index = index + 1
    else
      if not exists[v] then
        ret[index] = v
        index = index + 1
        exists[v] = true
      end
    end
  end
  return ret
end

--[[
------------------------------------------------------------------------------------
-- numKeys
--
-- This takes a table and returns an array containing the numbers of any numerical
-- keys that have non-nil values, sorted in numerical order.
------------------------------------------------------------------------------------
--]]
function p.numKeys(t)
  checkType('numKeys', 1, t, 'table')
  local isPositiveInteger = p.isPositiveInteger
  local nums = {}
  local index = 1
  for k, _ in pairs(t) do
    if isPositiveInteger(k) then
      nums[index] = k
      index = index + 1
    end
  end
  table.sort(nums)
  return nums
end

--[[
------------------------------------------------------------------------------------
-- affixNums
--
-- This takes a table and returns an array containing the numbers of keys with the
-- specified prefix and suffix.
-- affixNums({a1 = 'foo', a3 = 'bar', a6 = 'baz'}, "a")
--		↓
-- {1, 3, 6}.
------------------------------------------------------------------------------------
--]]
function p.affixNums(t, prefix, suffix)
  local check = _check('affixNums')
  check(1, t, 'table')
  check(2, prefix, 'string', true)
  check(3, suffix, 'string', true)

  local function cleanPattern(s)
    -- Cleans a pattern so that the magic characters ()%.[]*+-?^$ are interpreted literally.
    s = s:gsub('([%(%)%%%.%[%]%*%+%-%?%^%$])', '%%%1')
    return s
  end

  prefix = prefix or ''
  suffix = suffix or ''
  prefix = cleanPattern(prefix)
  suffix = cleanPattern(suffix)
  local pattern = '^' .. prefix .. '([1-9]%d*)' .. suffix .. '$'

  local nums = {}
  local index = 1
  for k, _ in pairs(t) do
    if type(k) == 'string' then
      local num = mw.ustring.match(k, pattern)
      if num then
        nums[index] = tonumber(num)
        index = index + 1
      end
    end
  end
  table.sort(nums)
  return nums
end

--[[
------------------------------------------------------------------------------------
-- numData
--
-- Given a table with keys like ("foo1", "bar1", "foo2", "baz2"), returns a table
-- of subtables in the format
-- { [1] = {foo = 'text', bar = 'text'}, [2] = {foo = 'text', baz = 'text'} }
-- Keys that don't end with an integer are stored in a subtable named "other".
-- The compress option compresses the table so that it can be iterated over with
-- ipairs.
------------------------------------------------------------------------------------
--]]
function p.numData(t, compress)
  local check = _check('numData')
  check(1, t, 'table')
  check(2, compress, 'boolean', true)

  local ret = {}
  for k, v in pairs(t) do
    local prefix, num = tostring(k):match('^([^0-9]*)([1-9][0-9]*)$')
    if num then
      num = tonumber(num)
      local subtable = ret[num] or {}
      if prefix == '' then
        -- Positional parameters match the blank string; put them at the start of the subtable instead.
        prefix = 1
      end
      subtable[prefix] = v
      ret[num] = subtable
    else
      local subtable = ret.other or {}
      subtable[k] = v
      ret.other = subtable
    end
  end
  if compress then
    local other = ret.other
    ret = p.compressSparseArray(ret)
    ret.other = other
  end
  return ret
end

--[[
------------------------------------------------------------------------------------
-- compressSparseArray
--
-- This takes an array with one or more nil values, and removes the nil values
-- while preserving the order, so that the array can be safely traversed with
-- ipairs.
------------------------------------------------------------------------------------
--]]
function p.compressSparseArray(t)
  checkType('compressSparseArray', 1, t, 'table')
  local ret = {}
  local index = 1
  local nums = p.numKeys(t)
  for _, num in ipairs(nums) do
    ret[index] = t[num]
    index = index + 1
  end
  return ret
end

--[[
------------------------------------------------------------------------------------
-- sparseIpairs
--
-- This is an iterator for sparse arrays. It can be used like ipairs, but can
-- handle nil values.
------------------------------------------------------------------------------------
--]]
function p.sparseIpairs(t)
  checkType('sparseIpairs', 1, t, 'table')
  local nums = p.numKeys(t)
  local i = 0
  return function()
    i = i + 1
    local key = nums[i]
    if key then
      return key, t[key]
    else
      return nil, nil
    end
  end
end

--[[
------------------------------------------------------------------------------------
-- size
--
-- This returns the size of a key/value pair table. It will also work on arrays,
-- but for arrays it is more efficient to use the # operator.
------------------------------------------------------------------------------------
--]]
function p.size(t)
  checkType('size', 1, t, 'table')
  local i = 0
  for _ in pairs(t) do
    i = i + 1
  end
  return i
end

--[[
-- This returns the length of a table, or the first integer key n counting from
-- 1 such that t[n + 1] is nil. It is similar to the operator #, but may return
-- a different value when there are gaps in the array portion of the table.
-- Intended to be used on data loaded with mw.loadData. For other tables, use #.
--]]
function p.length(t)
  local i = 0
  repeat
    i = i + 1
  until t[i] == nil
  return i - 1
end

--[[
Takes table and a value to be found.
If the value is in the array portion of the table, return true.
If the value is in the hashmap or not in the table, return false.
]]
function p.contains(list, x)
  for _, v in ipairs(list) do
    if v == x then
      return true
    end
  end
  return false
end

--[[
	Finds key for specified value in a given table.
	Roughly equivalent to reversing the key-value pairs in the table –
		reversed_table = { [value1] = key1, [value2] = key2, ... }
	– and then returning reversed_table[valueToFind].

	The value can only be a string or a number
	(not nil, a boolean, a table, or a function).

	Only reliable if there is just one key with the specified value.
	Otherwise, the function returns the first key found,
	and the output is unpredictable.
]]
function p.keyFor(t, valueToFind)
  local check = _check('keyFor')
  check(1, t, 'table')
  check(2, valueToFind, { 'string', 'number' })

  for key, value in pairs(t) do
    if value == valueToFind then
      return key
    end
  end

  return nil
end

--[[
	The default sorting function used in export.keysToList if no keySort
	is defined.
]]
local function defaultKeySort(key1, key2)
  -- "number" < "string", so numbers will be sorted before strings.
  local type1, type2 = type(key1), type(key2)
  if type1 ~= type2 then
    return type1 < type2
  else
    return key1 < key2
  end
end

--[[
	Returns a list of the keys in a table, sorted using either the default
	table.sort function or a custom keySort function.
	If there are only numerical keys, numKeys is probably more efficient.
]]
function p.keysToList(t, keySort, checked)
  if not checked then
    local check = _check('keysToList')
    check(1, t, 'table')
    check(2, keySort, 'function', true)
  end

  local list = {}
  local index = 1
  for key, _ in pairs(t) do
    list[index] = key
    index = index + 1
  end

  -- Place numbers before strings, otherwise sort using <.
  if not keySort then
    keySort = defaultKeySort
  end

  table.sort(list, keySort)

  return list
end

--[[
	Iterates through a table, with the keys sorted using the keysToList function.
	If there are only numerical keys, sparseIpairs is probably more efficient.
]]
function p.sortedPairs(t, keySort)
  local check = _check('keysToList')
  check(1, t, 'table')
  check(2, keySort, 'function', true)

  local list = p.keysToList(t, keySort, true)

  local i = 0
  return function()
    i = i + 1
    local key = list[i]
    if key ~= nil then
      return key, t[key]
    else
      return nil, nil
    end
  end
end

function p.reverseIpairs(list)
  checkType('reverse_ipairs', 1, list, 'table')

  local i = #list + 1
  return function()
    i = i - 1
    if list[i] ~= nil then
      return i, list[i]
    else
      return nil, nil
    end
  end
end

--[=[
	Joins an array with serial comma and serial "and". An improvement on
	mw.text.listToText, which doesn't properly handle serial commas.

	Options:
		- italicizeConj
			Italicize conjunction: for [[Module:Template:also]]
		- dontTag
			Don't tag the serial comma and serial "and". For error messages, in
			which HTML cannot be used.
]=]
function p.serialCommaJoin(seq, options)
  local check = _check("serialCommaJoin", "table")
  check(1, seq)
  check(2, options, true)

  local length = #seq

  if not options then
    options = {}
  end

  local conj
  if length > 1 then
    conj = "and"
    if options.italicizeConj then
      conj = "''" .. conj .. "''"
    end
  end

  if length == 0 then
    return ""
  elseif length == 1 then
    return seq[1] -- nothing to join
  elseif length == 2 then
    return seq[1] .. " " .. conj .. " " .. seq[2]
  else
    local comma = options.dontTag and "," or '<span class="serial-comma">,</span>'
    conj = options.dontTag and ' ' .. conj .. " " or '<span class="serial-and"> ' .. conj .. '</span> '
    return table.concat(seq, ", ", 1, length - 1) ..
        comma .. conj .. seq[length]
  end
end

--[[
	Concatenates all values in the table that are indexed by a number, in order.
	sparseConcat{ a, nil, c, d }  =>  "acd"
	sparseConcat{ nil, b, c, d }  =>  "bcd"
]]
function p.sparseConcat(t, sep, i, j)
  local list = {}

  local list_i = 0
  for _, v in p.sparseIpairs(t) do
    list_i = list_i + 1
    list[list_i] = v
  end

  return table.concat(list, sep, i, j)
end

--[[
	Values of numberic keys in array portion of table are reversed:
	{ "a", "b", "c" } -> { "c", "b", "a" }
--]]
function p.reverse(t)
  checkType("reverse", 1, t, "table")

  local new_t = {}
  local new_t_i = 1
  for i = #t, 1, -1 do
    new_t[new_t_i] = t[i]
    new_t_i = new_t_i + 1
  end
  return new_t
end

function p.reverseConcat(t, sep, i, j)
  return table.concat(p.reverse(t), sep, i, j)
end

-- { "a", "b", "c" } -> { a = 1, b = 2, c = 3 }
function p.invert(array)
  checkType("invert", 1, array, "table")

  local map = {}
  for i, v in ipairs(array) do
    map[v] = i
  end

  return map
end

--[[
	{ "a", "b", "c" } -> { ["a"] = true, ["b"] = true, ["c"] = true }
--]]
function p.listToSet(t)
  checkType("listToSet", 1, t, "table")

  local set = {}
  for _, item in ipairs(t) do
    set[item] = true
  end
  return set
end

--[[
	Returns true if all keys in the table are consecutive integers starting at 1.
--]]
function p.isArray(t)
  checkType("isArray", 1, t, "table")

  local i = 0
  for _ in pairs(t) do
    i = i + 1
    if t[i] == nil then
      return false
    end
  end
  return true
end

--- Contatenates two arrays.
--- @param a1 table The first table; will be modified.
--- @param a2 table The second table; will be concatenated to the first one.
function p.arrayConcat(a1, a2)
  for i = 1, #a2 do
    a1[#a1 + 1] = a2[i]
  end
end

--- Applies a function to every items of the given table.
function p.map(table, f)
  local t = {}

  for k, v in pairs(table) do
    t[k] = f(v)
  end

  return t
end

--- Transforms a associative table to an array of key-value pairs.
function p.items(t)
  local res = {}

  for k, v in pairs(t) do
    table.insert(res, { k, v })
  end

  return res
end

return p