Difference between revisions of "Module:TableTools"
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local infinity = math.huge | local infinity = math.huge | ||
local checkType = libraryUtil.checkType | local checkType = libraryUtil.checkType | ||
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--[[ | --[[ | ||
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-- isPositiveInteger | -- isPositiveInteger | ||
-- | -- | ||
− | -- This function returns true if the given | + | -- 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 | -- 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 | -- useful for determining whether a given table key is in the array part or the | ||
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------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
--]] | --]] | ||
− | function p.isPositiveInteger( | + | function p.isPositiveInteger(v) |
− | if type( | + | if type(v) == 'number' and v >= 1 and floor(v) == v and v < infinity then |
return true | return true | ||
else | else | ||
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--[[ | --[[ | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
− | -- | + | -- isNan |
-- | -- | ||
− | -- This returns the | + | -- 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. | + | function p.isNan(v) |
− | + | if type(v) == 'number' and tostring(v) == '-nan' then | |
− | + | return true | |
− | + | else | |
+ | return false | ||
end | end | ||
− | + | end | |
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--[[ | --[[ | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
− | -- | + | -- shallowClone |
-- | -- | ||
− | -- This returns | + | -- 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. | + | function p.shallowClone(t) |
− | + | local ret = {} | |
− | + | for k, v in pairs(t) do | |
− | + | ret[k] = v | |
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− | local ret | + | |
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end | end | ||
return ret | return ret | ||
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--[[ | --[[ | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
− | -- | + | -- removeDuplicates |
-- | -- | ||
− | -- This | + | -- 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. | + | function p.removeDuplicates(t) |
− | + | checkType('removeDuplicates', 1, t, 'table') | |
− | + | local isNan = p.isNan | |
− | + | local ret, exists = {}, {} | |
− | + | for i, v in ipairs(t) do | |
− | local | + | if isNan(v) then |
− | for i | + | -- 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 | |
− | if | + | ret[#ret + 1] = v |
− | v = | + | exists[v] = true |
end | end | ||
− | + | end | |
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− | end | + | |
end | end | ||
return ret | return ret | ||
− | end | + | end |
--[[ | --[[ | ||
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checkType('affixNums', 2, prefix, 'string', true) | checkType('affixNums', 2, prefix, 'string', true) | ||
checkType('affixNums', 3, suffix, '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('([%(%)%%%.%[%]%*%+%-%?%^%$])', '%%%1') | ||
+ | return s | ||
+ | end | ||
+ | |||
prefix = prefix or '' | prefix = prefix or '' | ||
suffix = suffix or '' | suffix = suffix or '' | ||
+ | prefix = cleanPattern(prefix) | ||
+ | suffix = cleanPattern(suffix) | ||
local pattern = '^' .. prefix .. '([1-9]%d*)' .. suffix .. '$' | local pattern = '^' .. prefix .. '([1-9]%d*)' .. suffix .. '$' | ||
+ | |||
local nums = {} | local nums = {} | ||
for k, v in pairs(t) do | for k, v in pairs(t) do | ||
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table.sort(nums) | table.sort(nums) | ||
return nums | return nums | ||
+ | end | ||
+ | |||
+ | --[[ | ||
+ | ------------------------------------------------------------------------------------ | ||
+ | -- numData | ||
+ | -- | ||
+ | -- Given a table with keys like ("foo1", "bar1", "foo2", "baz2"), returns a table | ||
+ | -- of subtables in the format | ||
+ | -- { [1] = {foo = 'text', bar = 'text'}, [2] = {foo = 'text', baz = 'text'} } | ||
+ | -- Keys that don't end with an integer are stored in a subtable named "other". | ||
+ | -- The compress option compresses the table so that it can be iterated over with | ||
+ | -- ipairs. | ||
+ | ------------------------------------------------------------------------------------ | ||
+ | --]] | ||
+ | function p.numData(t, compress) | ||
+ | checkType('numData', 1, t, 'table') | ||
+ | checkType('numData', 2, compress, 'boolean', true) | ||
+ | local ret = {} | ||
+ | for k, v in pairs(t) do | ||
+ | local prefix, num = mw.ustring.match(tostring(k), '^([^0-9]*)([1-9][0-9]*)$') | ||
+ | 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 | end | ||
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local key = nums[i] | local key = nums[i] | ||
return key, t[key] | return key, t[key] | ||
+ | else | ||
+ | return nil, nil | ||
end | end | ||
end | end |
Latest revision as of 13:23, 8 April 2016
Documentation for this module may be created at Module:TableTools/doc
Script error: Lua error: Internal error: The interpreter exited with status 126.
--[[ ------------------------------------------------------------------------------------ -- 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