Editing Module talk:TableTools (section)

== Infinite loop in deepCopy ==

There's a bug in the <code>deepCopy</code> function which manifests with any kind of recursive table nesting. However, it's easy to fix, as you just need to cache the new copy in {{code|already_seen|lua}} before doing the {{code|pairs|lua}} loop, like this:
<syntaxhighlight lang=lua>
	if type(orig) == 'table' then
		copy = {}
		already_seen[orig] = copy
		for orig_key, orig_value in pairs(orig) do
			copy[_deepCopy(orig_key, includeMetatable, already_seen)] = _deepCopy(orig_value, includeMetatable, already_seen)
		end

		if includeMetatable then
			local mt = getmetatable(orig)
			if mt ~= nil then
				local mt_copy = _deepCopy(mt, includeMetatable, already_seen)
				setmetatable(copy, mt_copy)
				already_seen[mt] = mt_copy
			end
		end
	else -- number, string, boolean, etc
		copy = orig
	end
</syntaxhighlight>
[[User:Theknightwho|Theknightwho]] ([[User talk:Theknightwho|talk]]) 13:03, 14 April 2024 (UTC)

:{{re|Theknightwho}} You may want to propose such changes in the sandbox. [[User:Alexiscoutinho|Alexis Coutinho]] ([[User talk:Alexiscoutinho|talk]]) <sup>&#91;''[[WP:PING|ping&nbsp;me]]''&#93;</sup> 00:09, 23 April 2024 (UTC)
::@[[User:Alexiscoutinho|Alexiscoutinho]] I've updated <code>deepCopy</code> with a fix in the sandbox, and introduced various optimisations, but I haven't added <code>deepEquals</code> since I'm not sure whether the WP would want table metamethods to be respected when traversing over the tables. The Wiktionary version does a strict comparison (i.e. metamethods are ignored), but that's what makes sense for our needs; however, that might be unintuitive for users who want to compare frame argument tables, for instance. [[User:Theknightwho|Theknightwho]] ([[User talk:Theknightwho|talk]]) 16:05, 24 April 2024 (UTC)