Module:TableTools: Difference between revisions
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add getIntersection function
(better variable name - getUnion deals with all tables, not just arrays) |
(add getIntersection function) |
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| Line 38: | Line 38: | ||
-- | -- | ||
-- This returns the union of the values of n tables, as an array. For example, for | -- 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, 3, 5, | -- the tables {1, 3, 4, 5, foo = 7} and {2, bar = 3, 5, 6}, getUnion will return | ||
-- {1, 2, 3, 4, 5, 6, 7}. | -- {1, 2, 3, 4, 5, 6, 7}. | ||
------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------ | ||
| Line 54: | Line 54: | ||
end | end | ||
table.sort(ret) | table.sort(ret) | ||
return ret | |||
end | end | ||
--[[ | |||
------------------------------------------------------------------------------------ | |||
-- getIntersection | |||
-- | |||
-- 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}, | |||
-- getIntersection will return {3, 5}. | |||
------------------------------------------------------------------------------------ | |||
--]] | |||
function p.getIntersection(...) | |||
local tables = {...} | |||
local vals, ret = {} | |||
local lim = #tables | |||
for _, t in ipairs(tables) do | |||
for k, v in pairs(t) do | |||
local valCount = vals[v] or 0 | |||
vals[v] = valCount + 1 | |||
end | |||
end | |||
for val, count in pairs(vals) do | |||
if count == lim then | |||
ret[#ret + 1] = val | |||
end | |||
end | |||
table.sort(ret) | |||
return ret | |||
end | |||
--[[ | --[[ | ||
