Module:TableTools: Difference between revisions
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(start module with useful tools for dealing with Lua tables) |
(add getNumKeys function and improve the comments, add the beginnings of a sparseIpairs function) |
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--[[ |
--[[ |
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----------------------------------------------------------------------------------- |
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⚫ | |||
-- Helper functions |
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-- |
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-- if not. Although it doesn't operate on tables, it is included here as it is |
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-- useful for determining whether a given table key is in the array part or the |
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-- hash part of the table. |
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----------------------------------------------------------------------------------- |
----------------------------------------------------------------------------------- |
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--]] |
--]] |
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function p.isPositiveInteger(num) |
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⚫ | |||
⚫ | |||
if type(num) == 'number' and num >= 1 and floor(num) == num and num < infinity then |
if type(num) == 'number' and num >= 1 and floor(num) == num and num < infinity then |
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return true |
return true |
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--[[ |
--[[ |
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----------------------------------------------------------------------------------- |
----------------------------------------------------------------------------------- |
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-- getNumKeys |
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⚫ | |||
-- |
-- |
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-- This takes |
-- This takes a table and returns an array containing the numbers of any numerical |
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-- keys that have non-nil values, sorted in numerical order. |
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--]] |
--]] |
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function p. |
function p.getNumKeys(t) |
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local |
local isPositiveInteger = p.isPositiveInteger |
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local nums = {} |
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for k, v in pairs(t) do |
for k, v in pairs(t) do |
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if isPositiveInteger(k) then |
if isPositiveInteger(k) then |
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end |
end |
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end |
end |
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table.sort(nums) |
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return nums |
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end |
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--[[ |
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----------------------------------------------------------------------------------- |
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-- |
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-- This takes an array with one or more nil values, and removes the nil values |
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----------------------------------------------------------------------------------- |
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--]] |
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function p.compressSparseArray(t) |
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local ret = {} |
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local nums = p.getNumKeys(t) |
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table.sort(nums) |
table.sort(nums) |
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for _, num in ipairs(nums) do |
for _, num in ipairs(nums) do |
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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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-- sparseIpairs |
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-- |
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-- This is an iterator for sparse arrays. It can be used like ipairs, but can |
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-- handle nil values. |
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----------------------------------------------------------------------------------- |
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--]] |
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-- function p.sparseIpairs(t) |
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-- local nums = p.getNumKeys(t) |
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return p |
return p |