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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.
Module:TableTools | success: 9, error: 0, skipped: 0 |
Module:TableTools/sandbox | success: 9, error: 0, skipped: 0 |
To use any of the functions, first you must load the module.
localTableTools=require('Module:TableTools')
TableTools.isPositiveInteger(value)
Returnstrue
ifvalue
is a positive integer, andfalse
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.
TableTools.isNan(value)
Returnstrue
ifvalue
is aNaN value, andfalse
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 value is used as a table key.)
TableTools.shallowClone(t)
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. If you want to make a new table with no shared subtables and with metatables transferred, you can usemw.clone
instead. If you want to make a new table with no shared subtables and without metatables transferred, usedeepCopy
with thenoMetatable
option.
TableTools.removeDuplicates(t)
Removes duplicate values from an array.This function is only designed to work with standard arrays: keys that are not positive integers are ignored, as are all values after the firstnil
value. (For arrays containingnil
values, you can usecompressSparseArray
first.) The function tries to preserve the order of the array: the earliest non-unique value is kept, and all subsequent duplicate values are removed.
{5,4,4,3,4,2,2,1}
removeDuplicates
will return{5,4,3,2,1}
TableTools.numKeys(t)
Takes a tablet
and returns an array containing the numbers of any positive integer keys that have non-nil values, sorted in numerical order.
{'foo',nil,'bar','baz',a='b'}
numKeys
will return{1,3,4}
TableTools.affixNums(t,prefix,suffix)
Takes a tablet
and returns an array containing the numbers of keys with the optional prefixprefix
and the optional suffixsuffix
.
{a1='foo',a3='bar',a6='baz'}
'a'
,affixNums
will return{1,3,6}
All characters inprefix
andsuffix
are interpreted literally.
TableTools.numData(t,compress)
"foo1"
,"bar1"
,"foo2"
, and"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 withipairs
.
TableTools.compressSparseArray(t)
Takes an arrayt
with one or more nil values, and removes the nil values while preserving the order, so that the array can be safely traversed withipairs
. Any keys that are not positive integers are removed.
{1,nil,foo='bar',3,2}
compressSparseArray
will return{1,3,2}
TableTools.sparseIpairs(t)
This is an iterator function for traversing a sparse arrayt
. It is similar toipairs
, but will continue to iterate until the highest numerical key, whereasipairs
may stop after the firstnil
value. Any keys that are not positive integers are ignored.
UsuallysparseIpairs
is used in a genericfor
loop.
fori,vinTableTools.sparseIpairs(t)do-- code blockend
Note thatsparseIpairs
uses thepairs
function in its implementation. Although some table keys appear to be ignored, all table keys are accessed when it is run.
TableTools.size(t)
Finds the size of a key/value pair table.
For example, for the table{foo='foo',bar='bar'}
size
will return2
.The function will also work on arrays, but for arrays it is more efficient to use the#
operator.Note that to find the table size, this function uses thepairs
function to iterate through all of the table keys.
TableTools.keysToList(t,keySort)
Returns a list of the keys in a table, sorted using either a default comparison function or a customkeySort
function, which follows the same rules as thecomp
function supplied totable.sort
.
TableTools.sortedPairs(t,keySort)
Iterates through a table, with the keys sorted using thekeysToList
function. If there are only numerical keys,sparseIpairs
is probably more efficient.
TableTools.isArray(t)
Returns true if all keys in the table are consecutive integers starting at1
.
TableTools.listToSet(arr)
Creates a set from the array part of the tablearr
. Indexing the set by any of the values inarr
returnstrue
.
localset=TableTools.listToSet{"a","b","c"}assert(set["a"]===true)
TableTools.invert(t)
Transposes the keys and values in an array.For example,invert{ "a", "b", "c" }
yields{ a = 1, b = 2, c = 3 }
.
TableTools.deepCopy(orig,noMetatable,alreadySeen)
Creates a copy of the tableorig
. As withmw.clone
, all values that are not functions are duplicated and the identity of tables is preserved. IfnoMetatable
istrue
, then the metatable (if any) is not copied. Can copy tables loaded withmw.loadData
.
Similar tomw.clone
, butmw.clone
cannot copy tables loaded withmw.loadData
and does not allow metatablesnot to be copied.
TableTools.sparseConcat(t,sep)
Concatenates all values in the table that are indexed by a positive integer, in order.
TableTools.length(t)
Returns the length of a table, or the first integer keyn
counting from0
such thatt[n + 1]
isnil
. 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 withmw.loadData
and onframe.args
. Both use a metatable such that#mw.loadData("module:...")
and#frame.args
don't work correctly. For other tables, use#
.
TableTools.inArray(arr,valueToFind)
Returnstrue
ifvalueToFind
is a member of the arrayarr
, andfalse
otherwise.
--[[-------------------------------------------------------------------------------------- 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. ----------------------------------------------------------------------------------------]]locallibraryUtil=require('libraryUtil')localp={}-- Define often-used variables and functions.localfloor=math.floorlocalinfinity=math.hugelocalcheckType=libraryUtil.checkTypelocalcheckTypeMulti=libraryUtil.checkTypeMulti--[[-------------------------------------------------------------------------------------- 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.--------------------------------------------------------------------------------------]]functionp.isPositiveInteger(v)iftype(v)=='number'andv>=1andfloor(v)==vandv<infinitythenreturntrueelsereturnfalseendend--[[-------------------------------------------------------------------------------------- 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.--------------------------------------------------------------------------------------]]functionp.isNan(v)iftype(v)=='number'andtostring(v)=='-nan'thenreturntrueelsereturnfalseendend--[[-------------------------------------------------------------------------------------- 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.--------------------------------------------------------------------------------------]]functionp.shallowClone(t)localret={}fork,vinpairs(t)doret[k]=vendreturnretend--[[-------------------------------------------------------------------------------------- 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.--------------------------------------------------------------------------------------]]functionp.removeDuplicates(t)checkType('removeDuplicates',1,t,'table')localisNan=p.isNanlocalret,exists={},{}fori,vinipairs(t)doifisNan(v)then-- NaNs can't be table keys, and they are also unique, so we don't need to check existence.ret[#ret+1]=velseifnotexists[v]thenret[#ret+1]=vexists[v]=trueendendendreturnretend--[[-------------------------------------------------------------------------------------- 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.--------------------------------------------------------------------------------------]]functionp.numKeys(t)checkType('numKeys',1,t,'table')localisPositiveInteger=p.isPositiveIntegerlocalnums={}fork,vinpairs(t)doifisPositiveInteger(k)thennums[#nums+1]=kendendtable.sort(nums)returnnumsend--[[-------------------------------------------------------------------------------------- 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}.--------------------------------------------------------------------------------------]]functionp.affixNums(t,prefix,suffix)checkType('affixNums',1,t,'table')checkType('affixNums',2,prefix,'string',true)checkType('affixNums',3,suffix,'string',true)localfunctioncleanPattern(s)-- Cleans a pattern so that the magic characters ()%.[]*+-?^$ are interpreted literally.s=s:gsub('([%(%)%%%.%[%]%*%+%-%?%^%$])','%%%1')returnsendprefix=prefixor''suffix=suffixor''prefix=cleanPattern(prefix)suffix=cleanPattern(suffix)localpattern='^'..prefix..'([1-9]%d*)'..suffix..'$'localnums={}fork,vinpairs(t)doiftype(k)=='string'thenlocalnum=mw.ustring.match(k,pattern)ifnumthennums[#nums+1]=tonumber(num)endendendtable.sort(nums)returnnumsend--[[-------------------------------------------------------------------------------------- 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.--------------------------------------------------------------------------------------]]functionp.numData(t,compress)checkType('numData',1,t,'table')checkType('numData',2,compress,'boolean',true)localret={}fork,vinpairs(t)dolocalprefix,num=mw.ustring.match(tostring(k),'^([^0-9]*)([1-9][0-9]*)$')ifnumthennum=tonumber(num)localsubtable=ret[num]or{}ifprefix==''then-- Positional parameters match the blank string; put them at the start of the subtable instead.prefix=1endsubtable[prefix]=vret[num]=subtableelselocalsubtable=ret.otheror{}subtable[k]=vret.other=subtableendendifcompressthenlocalother=ret.otherret=p.compressSparseArray(ret)ret.other=otherendreturnretend--[[-------------------------------------------------------------------------------------- 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.--------------------------------------------------------------------------------------]]functionp.compressSparseArray(t)checkType('compressSparseArray',1,t,'table')localret={}localnums=p.numKeys(t)for_,numinipairs(nums)doret[#ret+1]=t[num]endreturnretend--[[-------------------------------------------------------------------------------------- sparseIpairs---- This is an iterator for sparse arrays. It can be used like ipairs, but can-- handle nil values.--------------------------------------------------------------------------------------]]functionp.sparseIpairs(t)checkType('sparseIpairs',1,t,'table')localnums=p.numKeys(t)locali=0locallim=#numsreturnfunction()i=i+1ifi<=limthenlocalkey=nums[i]returnkey,t[key]elsereturnnil,nilendendend--[[-------------------------------------------------------------------------------------- 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.--------------------------------------------------------------------------------------]]functionp.size(t)checkType('size',1,t,'table')locali=0forkinpairs(t)doi=i+1endreturniendlocalfunctiondefaultKeySort(item1,item2)-- "number" < "string", so numbers will be sorted before strings.localtype1,type2=type(item1),type(item2)iftype1~=type2thenreturntype1<type2else-- This will fail with table, boolean, function.returnitem1<item2endend--[[Returns a list of the keys in a table, sorted using either a defaultcomparison function or a custom keySort function.]]functionp.keysToList(t,keySort,checked)ifnotcheckedthencheckType('keysToList',1,t,'table')checkTypeMulti('keysToList',2,keySort,{'function','boolean','nil'})endlocallist={}localindex=1forkey,valueinpairs(t)dolist[index]=keyindex=index+1endifkeySort~=falsethenkeySort=type(keySort)=='function'andkeySortordefaultKeySorttable.sort(list,keySort)endreturnlistend--[[Iterates through a table, with the keys sorted using the keysToList function.If there are only numerical keys, sparseIpairs is probably more efficient.]]functionp.sortedPairs(t,keySort)checkType('sortedPairs',1,t,'table')checkType('sortedPairs',2,keySort,'function',true)locallist=p.keysToList(t,keySort,true)locali=0returnfunction()i=i+1localkey=list[i]ifkey~=nilthenreturnkey,t[key]elsereturnnil,nilendendend--[[Returns true if all keys in the table are consecutive integers starting at 1.--]]functionp.isArray(t)checkType("isArray",1,t,"table")locali=0fork,vinpairs(t)doi=i+1ift[i]==nilthenreturnfalseendendreturntrueend-- { "a", "b", "c" } -> { a = 1, b = 2, c = 3 }functionp.invert(array)checkType("invert",1,array,"table")localmap={}fori,vinipairs(array)domap[v]=iendreturnmapend--[[{ "a", "b", "c" } -> { ["a"] = true, ["b"] = true, ["c"] = true }--]]functionp.listToSet(t)checkType("listToSet",1,t,"table")localset={}for_,iteminipairs(t)doset[item]=trueendreturnsetend--[[Recursive deep copy function.Preserves identities of subtables.]]localfunction_deepCopy(orig,includeMetatable,already_seen)-- Stores copies of tables indexed by the original table.already_seen=already_seenor{}localcopy=already_seen[orig]ifcopy~=nilthenreturncopyendiftype(orig)=='table'thencopy={}fororig_key,orig_valueinpairs(orig)docopy[deepcopy(orig_key,includeMetatable,already_seen)]=deepcopy(orig_value,includeMetatable,already_seen)endalready_seen[orig]=copyifincludeMetatablethenlocalmt=getmetatable(orig)ifmt~=nilthenlocalmt_copy=deepcopy(mt,includeMetatable,already_seen)setmetatable(copy,mt_copy)already_seen[mt]=mt_copyendendelse-- number, string, boolean, etccopy=origendreturncopyendfunctionp.deepCopy(orig,noMetatable,already_seen)checkType("deepCopy",3,already_seen,"table",true)return_deepCopy(orig,notnoMetatable,already_seen)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"]]functionp.sparseConcat(t,sep,i,j)locallist={}locallist_i=0for_,vinp.sparseIpairs(t)dolist_i=list_i+1list[list_i]=vendreturntable.concat(list,sep,i,j)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 #.-- Note: #frame.args in frame object always be set to 0, regardless of-- the number of unnamed template parameters, so use this function for-- frame.args.--]]functionp.length(t)locali=1whilet[i]~=nildoi=i+1endreturni-1endfunctionp.inArray(arr,valueToFind)checkType("inArray",1,arr,"table")-- if valueToFind is nil, error?for_,vinipairs(arr)doifv==valueToFindthenreturntrueendendreturnfalseendreturnp