Module:TableTools: Difference between revisions

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Module:TableTools (edit)

Revision as of 05:46, 20 December 2013

6,866 bytes removed ,  20 December 2013
split set functions out to Module:Set
(reinstate shallowClone - saw a use for it in p.complement - and write p.valueComplement)
(split set functions out to Module:Set)
Line 96: Line 96:
end
end
return ret
return ret
end
end
 
--[[
------------------------------------------------------------------------------------
-- union
--
-- This returns the union of the key/value pairs of n tables. If any of the tables
-- contain different values for the same table key, the table value is converted
-- to an array holding all of the different values.
------------------------------------------------------------------------------------
--]]
function p.union(...)
local lim = select('#', ...)
if lim < 2 then
error("too few arguments to 'union' (minimum is 2, received " .. lim .. ')', 2)
end
local ret, trackArrays = {}, {}
for i = 1, lim do
local t = select(i, ...)
checkType('union', i, t, 'table')
for k, v in pairs(t) do
local retKey = ret[k]
if retKey == nil then
ret[k] = v
elseif retKey ~= v then
if trackArrays[k] then
local array = ret[k]
local valExists
for _, arrayVal in ipairs(array) do
if arrayVal == v then
valExists = true
break
end
end
if not valExists then
array[#array + 1] = v
ret[k] = array
end
else
ret[k] = {ret[k], v}
trackArrays[k] = true
end
end
end
end
return ret
end
 
--[[
------------------------------------------------------------------------------------
-- valueUnion
--
-- This returns the union of the values of n tables, as an array. For example, for
-- the tables {1, 3, 4, 5, foo = 7} and {2, bar = 3, 5, 6}, union will return
-- {1, 2, 3, 4, 5, 6, 7}.
------------------------------------------------------------------------------------
--]]
function p.valueUnion(...)
local lim = select('#', ...)
if lim < 2 then
error("too few arguments to 'valueUnion' (minimum is 2, received " .. lim .. ')', 2)
end
local isNan = p.isNan
local ret, exists = {}, {}
for i = 1, lim do
local t = select(i, ...)
checkType('valueUnion', i, t, 'table')
for k, v in pairs(t) do
if isNan(v) then
ret[#ret + 1] = v
elseif not exists[v] then
ret[#ret + 1] = v
exists[v] = true
end
end
end
return ret
end
 
--[[
------------------------------------------------------------------------------------
-- intersection
--
-- This returns the intersection of the key/value pairs of n tables. Both the key
-- and the value must match to be included in the resulting table.
------------------------------------------------------------------------------------
--]]
function p.intersection(...)
local lim = select('#', ...)
if lim < 2 then
error("too few arguments to 'intersection' (minimum is 2, received " .. lim .. ')', 2)
end
local ret, track, pairCounts = {}, {}, {}
for i = 1, lim do
local t = select(i, ...)
checkType('intersection', i, t, 'table')
for k, v in pairs(t) do
local trackVal = track[k]
if trackVal == nil then
track[k] = v
pairCounts[k] = 1
elseif trackVal == v then
pairCounts[k] = pairCounts[k] + 1
end
end
end
for k, v in pairs(track) do
if pairCounts[k] == lim then
ret[k] = v
end
end
return ret
end
 
--[[
------------------------------------------------------------------------------------
-- valueIntersection
--
-- This returns the intersection of the values of n tables, as an array. For
-- example, for the tables {1, 3, 4, 5, foo = 7} and {2, bar = 3, 5, 6},
-- intersection will return {3, 5}.
------------------------------------------------------------------------------------
--]]
function p.valueIntersection(...)
local lim = select('#', ...)
if lim < 2 then
error("too few arguments to 'valueIntersection' (minimum is 2, received " .. lim .. ')', 2)
end
local isNan = p.isNan
local vals, ret = {}, {}
local isSameTable = true -- Tracks table equality.
local tableTemp -- Used to store the table from the previous loop so that we can check table equality.
for i = 1, lim do
local t = select(i, ...)
checkType('valueIntersection', i, t, 'table')
if tableTemp and t ~= tableTemp then
isSameTable = false
end
tableTemp = t
for k, v in pairs(t) do
-- NaNs are never equal to any other value, so they can't be in the intersection.
-- Which is lucky, as they also can't be table keys.
if not isNan(v) then
local valCount = vals[v] or 0
vals[v] = valCount + 1
end
end
end
if isSameTable then
-- If all the tables are equal, then the intersection is that table (including NaNs).
-- All we need to do is convert it to an array and remove duplicate values.
for k, v in pairs(tableTemp) do
ret[#ret + 1] = v
end
return p.removeDuplicates(ret)
end
for val, count in pairs(vals) do
if count == lim then
ret[#ret + 1] = val
end
end
return ret
end
 
--[[
------------------------------------------------------------------------------------
-- complement
--
-- This returns the relative complement of t1, t2, ..., in tn. The complement
-- is of key/value pairs. This is equivalent to all the key/value pairs that are in
-- tn but are not in t1, t2, ... tn-1.
------------------------------------------------------------------------------------
--]]
function p.complement(...)
local lim = select('#', ...)
if lim < 2 then
error("too few arguments to 'complement' (minimum is 2, received " .. lim .. ')', 2)
end
--[[
-- Now we know that we have at least two sets.
-- First, get all the key/value pairs in tn. We can't simply make ret equal to tn,
-- as that will affect the value of tn for the whole module.
--]]
local tn = select(lim, ...)
checkType('complement', lim, tn, 'table')
local ret = p.shallowClone(tn)
-- Remove all the key/value pairs in t1, t2, ..., tn-1.
for i = 1, lim - 1 do
local t = select(i, ...)
checkType('complement', i, t, 'table')
for k, v in pairs(t) do
if ret[k] == v then
ret[k] = nil
end
end
end
return ret
end
 
--[[
------------------------------------------------------------------------------------
-- valueComplement
--
-- This returns an array containing the relative complement of t1, t2, ..., in tn.
-- The complement is of values only. This is equivalent to all the values that are
-- in tn but are not in t1, t2, ... tn-1.
------------------------------------------------------------------------------------
--]]
function p.valueComplement(...)
local lim = select('#', ...)
if lim < 2 then
error("too few arguments to 'valueComplement' (minimum is 2, received " .. lim .. ')', 2)
end
local isNan = p.isNan
local ret, exists = {}, {}
for i = 1, lim - 1 do
local t = select(i, ...)
checkType('valueComplement', i, t, 'table')
for k, v in pairs(t) do
if not isNan(v) then
-- NaNs cannot be table keys, and they are also unique so cannot be equal to anything in tn.
exists[v] = true
end
end
end
local tn = select(lim, ...)
checkType('valueComplement', lim, tn, 'table')
for k, v in pairs(tn) do
if isNan(v) or exists[v] == nil then
ret[#ret + 1] = v
end
end
return ret
end


--[[
--[[
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