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.
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.
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. For example, for the table{5,4,4,3,4,2,2,1}removeDuplicates will return{5,4,3,2,1}
Takes a tablet and returns an array containing the numbers of any positive integer keys that have non-nil values, sorted in numerical order. For example, for the table{'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. For example, for the table{a1='foo',a3='bar',a6='baz'} and the prefix'a',affixNums will return{1,3,6}. All characters inprefix andsuffix are interpreted literally.
TableTools.numData(t,compress)
Given a table with keys like"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. For example, for the table{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.
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.
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)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.
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.
