Module:TableTools/doc
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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 Quality
editModule:TableTools | success: 9, error: 0, skipped: 0 |
Module:TableTools/sandbox | success: 9, error: 0, skipped: 0 |
- See test cases
- Diff sandbox code
Loading the module
editTo use any of the functions, first you must load the module.
local TableTools = require('Module:TableTools')
Functions
editisPositiveInteger
editTableTools.isPositiveInteger(value)
Returns true
if 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.
isNan
editTableTools.isNan(value)
Returns true
if value
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 value is used as a table key.)
shallowClone
editTableTools.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 use mw.clone
instead.
If you want to make a new table with no shared subtables and without metatables transferred, use deepCopy
with the noMetatable
option.
removeDuplicates
editTableTools.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 first nil
value.
(For arrays containing nil
values, you can use compressSparseArray
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}
numKeys
editTableTools.numKeys(t)
Takes a table t
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}
.
affixNums
editTableTools.affixNums(t, prefix, suffix)
Takes a table t
and returns an array containing the numbers of keys with the optional prefix prefix
and the optional suffix suffix
.
For example, for the table
{a1 = 'foo', a3 = 'bar', a6 = 'baz'}
and the prefix 'a'
, affixNums
will return
{1, 3, 6}
.
All characters in prefix
and suffix
are interpreted literally.
numData
editTableTools.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 with ipairs
.
compressSparseArray
editTableTools.compressSparseArray(t)
Takes an array t
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
.
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}
.
sparseIpairs
editTableTools.sparseIpairs(t)
This is an iterator function for traversing a sparse array t
.
It is similar to ipairs
, but will continue to iterate until the highest numerical key, whereas ipairs
may stop after the first nil
value.
Any keys that are not positive integers are ignored.
Usually sparseIpairs
is used in a generic for
loop.
for i, v in TableTools.sparseIpairs(t) do
-- code block
end
Note that sparseIpairs
uses the pairs
function in its implementation.
Although some table keys appear to be ignored, all table keys are accessed when it is run.
size
editTableTools.size(t)
Finds the size of a key/value pair table.
For example, for the table
{foo = 'foo', bar = 'bar'}
, size
will return 2
.
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 the pairs
function to iterate through all of the table keys.
keysToList
editTableTools.keysToList(t, keySort)
Returns a list of the keys in a table, sorted using either a default comparison function or a custom keySort
function, which follows the same rules as the comp
function supplied to table.sort
.
sortedPairs
editTableTools.sortedPairs(t, keySort)
Iterates through a table, with the keys sorted using the keysToList
function.
If there are only numerical keys, sparseIpairs
is probably more efficient.
isArray
editTableTools.isArray(t)
Returns true if all keys in the table are consecutive integers starting at 1
.
listToSet
editTableTools.listToSet(arr)
Creates a set from the array part of the table arr
.
Indexing the set by any of the values in arr
returns true
.
local set = TableTools.listToSet { "a", "b", "c" }
assert(set["a"] === true)
invert
editTableTools.invert(t)
Transposes the keys and values in an array.
For example, invert{ "a", "b", "c" }
yields { a = 1, b = 2, c = 3 }
.
deepCopy
editTableTools.deepCopy(orig, noMetatable, alreadySeen)
Creates a copy of the table orig
.
As with mw.clone
, all values that are not functions are duplicated and the identity of tables is preserved.
If noMetatable
is true
, then the metatable (if any) is not copied.
Can copy tables loaded with mw.loadData
.
Similar to mw.clone
, but mw.clone
cannot copy tables loaded with mw.loadData
and does not allow metatables not to be copied.
sparseConcat
editTableTools.sparseConcat(t, sep)
Concatenates all values in the table that are indexed by a positive integer, in order.
length
editTableTools.length(t)
Returns the length of a table, or the first integer key n
counting from 0
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
and on frame.args
.
Both use a metatable such that #mw.loadData("module:...")
and #frame.args
don't work correctly.
For other tables, use #
.
inArray
editTableTools.inArray(arr, valueToFind)
Returns true
if valueToFind
is a member of the array arr
, and false
otherwise.