Module:TableTools: Difference between revisions
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(improved module formatting; improved isArray; added isArrayLike; fixed _deepCopy; and improved defaultKeySort, code by User:Alexiscoutinho) |
Richardpruen (talk | contribs) m (1 revision imported) |
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--[[ | |||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- | -- TableTools -- | ||
-- -- | -- -- | ||
-- This module includes a number of functions for dealing with Lua tables. -- | -- 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 | -- It is a meta-module, meant to be called from other Lua modules, and should -- | ||
-- be called directly from #invoke. | -- not be called directly from #invoke. -- | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | |||
local libraryUtil = require('libraryUtil') | local libraryUtil = require('libraryUtil') | ||
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local infinity = math.huge | local infinity = math.huge | ||
local checkType = libraryUtil.checkType | local checkType = libraryUtil.checkType | ||
--[[ | |||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- isPositiveInteger | -- isPositiveInteger | ||
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-- hash part of a table. | -- hash part of a table. | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | |||
function p.isPositiveInteger(v) | 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 | end | ||
--[[ | |||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- isNan | -- isNan | ||
-- | -- | ||
-- This function returns true if the given number is a NaN value, and false | -- This function returns true if the given number is a NaN value, and false | ||
-- not. Although it doesn't operate on tables, it is included here as it is | -- if not. Although it doesn't operate on tables, it is included here as it is | ||
-- for determining whether a value can be a valid table key. Lua will | -- useful for determining whether a value can be a valid table key. Lua will | ||
-- error if a NaN is used as a table key. | -- generate an error if a NaN is used as a table key. | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | |||
function p.isNan(v) | function p.isNan(v) | ||
if type(v) == 'number' and tostring(v) == '-nan' then | |||
return true | |||
else | |||
return false | |||
end | |||
end | end | ||
--[[ | |||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- shallowClone | -- shallowClone | ||
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-- table will have no metatable of its own. | -- table will have no metatable of its own. | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | |||
function p.shallowClone(t) | function p.shallowClone(t) | ||
local ret = {} | local ret = {} | ||
for k, v in pairs(t) do | for k, v in pairs(t) do | ||
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end | end | ||
--[[ | |||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- removeDuplicates | -- removeDuplicates | ||
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-- removed, but otherwise the array order is unchanged. | -- removed, but otherwise the array order is unchanged. | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | |||
function p.removeDuplicates(t) | function p.removeDuplicates(t) | ||
checkType('removeDuplicates', 1, t, 'table') | checkType('removeDuplicates', 1, t, 'table') | ||
local isNan = p.isNan | local isNan = p.isNan | ||
local ret, exists = {}, {} | local ret, exists = {}, {} | ||
for | for i, v in ipairs(t) do | ||
if isNan(v) then | if isNan(v) then | ||
-- NaNs can't be table keys, and they are also unique, so we don't need to check existence. | -- NaNs can't be table keys, and they are also unique, so we don't need to check existence. | ||
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exists[v] = true | exists[v] = true | ||
end | end | ||
end | end | ||
end | end | ||
return ret | return ret | ||
end | end | ||
--[[ | |||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- numKeys | -- numKeys | ||
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-- keys that have non-nil values, sorted in numerical order. | -- keys that have non-nil values, sorted in numerical order. | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | |||
function p.numKeys(t) | function p.numKeys(t) | ||
checkType('numKeys', 1, t, 'table') | checkType('numKeys', 1, t, 'table') | ||
local isPositiveInteger = p.isPositiveInteger | local isPositiveInteger = p.isPositiveInteger | ||
local nums = {} | local nums = {} | ||
for k in pairs(t) do | for k, v in pairs(t) do | ||
if isPositiveInteger(k) then | if isPositiveInteger(k) then | ||
nums[#nums + 1] = k | nums[#nums + 1] = k | ||
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end | end | ||
--[[ | |||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- affixNums | -- affixNums | ||
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-- This takes a table and returns an array containing the numbers of keys with the | -- This takes a table and returns an array containing the numbers of keys with the | ||
-- specified prefix and suffix. For example, for the table | -- specified prefix and suffix. For example, for the table | ||
-- {a1 = 'foo', a3 = 'bar', a6 = 'baz'} and the prefix "a", affixNums will | -- {a1 = 'foo', a3 = 'bar', a6 = 'baz'} and the prefix "a", affixNums will | ||
-- {1, 3, 6}. | -- return {1, 3, 6}. | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | |||
function p.affixNums(t, prefix, suffix) | function p.affixNums(t, prefix, suffix) | ||
checkType('affixNums', 1, t, 'table') | checkType('affixNums', 1, t, 'table') | ||
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local function cleanPattern(s) | local function cleanPattern(s) | ||
-- Cleans a pattern so that the magic characters ()%.[]*+-?^$ are interpreted literally. | -- Cleans a pattern so that the magic characters ()%.[]*+-?^$ are interpreted literally. | ||
s = s:gsub('([%(%)%%%.%[%]%*%+%-%?%^%$])', '%%%1') | |||
return s | |||
end | end | ||
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local nums = {} | local nums = {} | ||
for k in pairs(t) do | for k, v in pairs(t) do | ||
if type(k) == 'string' then | if type(k) == 'string' then | ||
local num = mw.ustring.match(k, pattern) | local num = mw.ustring.match(k, pattern) | ||
if num then | if num then | ||
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end | end | ||
--[[ | |||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- numData | -- numData | ||
-- | -- | ||
-- Given a table with keys like | -- Given a table with keys like ("foo1", "bar1", "foo2", "baz2"), returns a table | ||
-- of subtables in the format | -- of subtables in the format | ||
-- {[1] = {foo = 'text', bar = 'text'}, [2] = {foo = 'text', baz = 'text'}} | -- { [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". | -- Keys that don't end with an integer are stored in a subtable named "other". | ||
-- compress option compresses the table so that it can be iterated over with | -- The compress option compresses the table so that it can be iterated over with | ||
-- ipairs. | -- ipairs. | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | |||
function p.numData(t, compress) | function p.numData(t, compress) | ||
checkType('numData', 1, t, 'table') | checkType('numData', 1, t, 'table') | ||
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end | end | ||
--[[ | |||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- compressSparseArray | -- compressSparseArray | ||
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-- ipairs. | -- ipairs. | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | |||
function p.compressSparseArray(t) | function p.compressSparseArray(t) | ||
checkType('compressSparseArray', 1, t, 'table') | checkType('compressSparseArray', 1, t, 'table') | ||
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end | end | ||
--[[ | |||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- sparseIpairs | -- sparseIpairs | ||
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-- handle nil values. | -- handle nil values. | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | |||
function p.sparseIpairs(t) | function p.sparseIpairs(t) | ||
checkType('sparseIpairs', 1, t, 'table') | checkType('sparseIpairs', 1, t, 'table') | ||
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end | end | ||
--[[ | |||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
-- size | -- size | ||
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-- but for arrays it is more efficient to use the # operator. | -- but for arrays it is more efficient to use the # operator. | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | |||
function p.size(t) | function p.size(t) | ||
checkType('size', 1, t, 'table') | checkType('size', 1, t, 'table') | ||
local i = 0 | local i = 0 | ||
for | for k in pairs(t) do | ||
i = i + 1 | i = i + 1 | ||
end | end | ||
return i | return i | ||
end | end | ||
return p | return p |
Revision as of 13:11, 23 November 2021
Documentation for this module may be created at Module:TableTools/doc
--[[ ------------------------------------------------------------------------------------ -- 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. -- ------------------------------------------------------------------------------------ --]] local libraryUtil = require('libraryUtil') local p = {} -- Define often-used variables and functions. local floor = math.floor local infinity = math.huge local checkType = libraryUtil.checkType --[[ ------------------------------------------------------------------------------------ -- 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 --[[ ------------------------------------------------------------------------------------ -- 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 = {}, {} for i, 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[#ret + 1] = v else if not exists[v] then ret[#ret + 1] = v 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 = {} for k, v in pairs(t) do if isPositiveInteger(k) then nums[#nums + 1] = k 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. For example, for the table -- {a1 = 'foo', a3 = 'bar', a6 = 'baz'} and the prefix "a", affixNums will -- return {1, 3, 6}. ------------------------------------------------------------------------------------ --]] function p.affixNums(t, prefix, suffix) checkType('affixNums', 1, t, 'table') checkType('affixNums', 2, prefix, 'string', true) checkType('affixNums', 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 = {} for k, v in pairs(t) do if type(k) == 'string' then local num = mw.ustring.match(k, pattern) if num then nums[#nums + 1] = tonumber(num) 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) checkType('numData', 1, t, 'table') checkType('numData', 2, compress, 'boolean', true) local ret = {} for k, v in pairs(t) do local prefix, num = mw.ustring.match(tostring(k), '^([^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 nums = p.numKeys(t) for _, num in ipairs(nums) do ret[#ret + 1] = t[num] 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 local lim = #nums return function () i = i + 1 if i <= lim then local key = nums[i] 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 k in pairs(t) do i = i + 1 end return i end return p