Module:TableTools: Difference between revisions
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reinstate shallowClone - saw a use for it in p.complement - and write p.valueComplement |
split set functions out to Module:Set |
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Line 96: | Line 96: | ||
end |
end |
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return ret |
return ret |
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end |
end |
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--[[ |
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------------------------------------------------------------------------------------ |
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-- union |
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-- |
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-- This returns the union of the key/value pairs of n tables. If any of the tables |
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-- contain different values for the same table key, the table value is converted |
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-- to an array holding all of the different values. |
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------------------------------------------------------------------------------------ |
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--]] |
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function p.union(...) |
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local lim = select('#', ...) |
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if lim < 2 then |
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error("too few arguments to 'union' (minimum is 2, received " .. lim .. ')', 2) |
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end |
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local ret, trackArrays = {}, {} |
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for i = 1, lim do |
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local t = select(i, ...) |
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checkType('union', i, t, 'table') |
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for k, v in pairs(t) do |
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local retKey = ret[k] |
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if retKey == nil then |
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ret[k] = v |
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elseif retKey ~= v then |
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if trackArrays[k] then |
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local array = ret[k] |
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local valExists |
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for _, arrayVal in ipairs(array) do |
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if arrayVal == v then |
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valExists = true |
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break |
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end |
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end |
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if not valExists then |
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array[#array + 1] = v |
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ret[k] = array |
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end |
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else |
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ret[k] = {ret[k], v} |
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trackArrays[k] = true |
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end |
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end |
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end |
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end |
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return ret |
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end |
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--[[ |
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------------------------------------------------------------------------------------ |
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-- valueUnion |
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-- |
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-- This returns the union of the values of n tables, as an array. For example, for |
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-- the tables {1, 3, 4, 5, foo = 7} and {2, bar = 3, 5, 6}, union will return |
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-- {1, 2, 3, 4, 5, 6, 7}. |
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------------------------------------------------------------------------------------ |
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--]] |
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function p.valueUnion(...) |
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local lim = select('#', ...) |
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if lim < 2 then |
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error("too few arguments to 'valueUnion' (minimum is 2, received " .. lim .. ')', 2) |
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end |
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local isNan = p.isNan |
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local ret, exists = {}, {} |
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for i = 1, lim do |
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local t = select(i, ...) |
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checkType('valueUnion', i, t, 'table') |
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for k, v in pairs(t) do |
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if isNan(v) then |
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ret[#ret + 1] = v |
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elseif not exists[v] then |
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ret[#ret + 1] = v |
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exists[v] = true |
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end |
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end |
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end |
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return ret |
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end |
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--[[ |
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------------------------------------------------------------------------------------ |
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-- intersection |
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-- |
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-- This returns the intersection of the key/value pairs of n tables. Both the key |
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-- and the value must match to be included in the resulting table. |
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------------------------------------------------------------------------------------ |
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--]] |
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function p.intersection(...) |
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local lim = select('#', ...) |
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if lim < 2 then |
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error("too few arguments to 'intersection' (minimum is 2, received " .. lim .. ')', 2) |
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end |
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local ret, track, pairCounts = {}, {}, {} |
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for i = 1, lim do |
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local t = select(i, ...) |
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checkType('intersection', i, t, 'table') |
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for k, v in pairs(t) do |
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local trackVal = track[k] |
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if trackVal == nil then |
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track[k] = v |
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pairCounts[k] = 1 |
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elseif trackVal == v then |
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pairCounts[k] = pairCounts[k] + 1 |
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end |
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end |
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end |
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for k, v in pairs(track) do |
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if pairCounts[k] == lim then |
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ret[k] = v |
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end |
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end |
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return ret |
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end |
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--[[ |
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------------------------------------------------------------------------------------ |
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-- valueIntersection |
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-- |
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-- This returns the intersection of the values of n tables, as an array. For |
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-- example, for the tables {1, 3, 4, 5, foo = 7} and {2, bar = 3, 5, 6}, |
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-- intersection will return {3, 5}. |
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------------------------------------------------------------------------------------ |
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--]] |
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function p.valueIntersection(...) |
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local lim = select('#', ...) |
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if lim < 2 then |
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error("too few arguments to 'valueIntersection' (minimum is 2, received " .. lim .. ')', 2) |
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end |
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local isNan = p.isNan |
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local vals, ret = {}, {} |
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local isSameTable = true -- Tracks table equality. |
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local tableTemp -- Used to store the table from the previous loop so that we can check table equality. |
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for i = 1, lim do |
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local t = select(i, ...) |
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checkType('valueIntersection', i, t, 'table') |
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if tableTemp and t ~= tableTemp then |
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isSameTable = false |
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end |
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tableTemp = t |
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for k, v in pairs(t) do |
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-- NaNs are never equal to any other value, so they can't be in the intersection. |
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-- Which is lucky, as they also can't be table keys. |
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if not isNan(v) then |
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local valCount = vals[v] or 0 |
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vals[v] = valCount + 1 |
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end |
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end |
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end |
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if isSameTable then |
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-- If all the tables are equal, then the intersection is that table (including NaNs). |
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-- All we need to do is convert it to an array and remove duplicate values. |
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for k, v in pairs(tableTemp) do |
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ret[#ret + 1] = v |
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end |
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return p.removeDuplicates(ret) |
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end |
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for val, count in pairs(vals) do |
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if count == lim then |
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ret[#ret + 1] = val |
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end |
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end |
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return ret |
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end |
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--[[ |
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------------------------------------------------------------------------------------ |
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-- complement |
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-- |
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-- This returns the relative complement of t1, t2, ..., in tn. The complement |
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-- is of key/value pairs. This is equivalent to all the key/value pairs that are in |
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-- tn but are not in t1, t2, ... tn-1. |
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------------------------------------------------------------------------------------ |
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--]] |
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function p.complement(...) |
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local lim = select('#', ...) |
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if lim < 2 then |
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error("too few arguments to 'complement' (minimum is 2, received " .. lim .. ')', 2) |
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end |
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--[[ |
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-- Now we know that we have at least two sets. |
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-- First, get all the key/value pairs in tn. We can't simply make ret equal to tn, |
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-- as that will affect the value of tn for the whole module. |
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--]] |
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local tn = select(lim, ...) |
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checkType('complement', lim, tn, 'table') |
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local ret = p.shallowClone(tn) |
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-- Remove all the key/value pairs in t1, t2, ..., tn-1. |
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for i = 1, lim - 1 do |
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local t = select(i, ...) |
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checkType('complement', i, t, 'table') |
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for k, v in pairs(t) do |
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if ret[k] == v then |
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ret[k] = nil |
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end |
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end |
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end |
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return ret |
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end |
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--[[ |
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------------------------------------------------------------------------------------ |
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-- valueComplement |
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-- |
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-- This returns an array containing the relative complement of t1, t2, ..., in tn. |
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-- The complement is of values only. This is equivalent to all the values that are |
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-- in tn but are not in t1, t2, ... tn-1. |
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------------------------------------------------------------------------------------ |
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--]] |
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function p.valueComplement(...) |
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local lim = select('#', ...) |
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if lim < 2 then |
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error("too few arguments to 'valueComplement' (minimum is 2, received " .. lim .. ')', 2) |
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end |
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local isNan = p.isNan |
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local ret, exists = {}, {} |
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for i = 1, lim - 1 do |
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local t = select(i, ...) |
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checkType('valueComplement', i, t, 'table') |
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for k, v in pairs(t) do |
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if not isNan(v) then |
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-- NaNs cannot be table keys, and they are also unique so cannot be equal to anything in tn. |
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exists[v] = true |
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end |
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end |
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end |
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local tn = select(lim, ...) |
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checkType('valueComplement', lim, tn, 'table') |
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for k, v in pairs(tn) do |
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if isNan(v) or exists[v] == nil then |
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ret[#ret + 1] = v |
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end |
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end |
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return ret |
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end |
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--[[ |
--[[ |