string.gmatch and string.match have invalid return types #3357

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1. sewbacca

   changed the title [-]string.gmatch[/-] [+]`string.gmatch` and `string.match` have invalid return types[/+] on Feb 19, 2026
2. carsakiller commented on Feb 26, 2026

   

   carsakiller

   on Feb 26, 2026

   Collaborator

   More actions

   I was very confused by string|number until I remembered that there is the "index" syntax for patterns ()! Good catch!

   local header = "i\ttype\tmatched text"
   local txt = "name=steve,color=blue"
   
   print("string.match")
   
   local str = header
   local t = { string.match(txt, "()(%w+)=([%w]+)()") }
   for k, v in ipairs(t) do
   	str = str .. string.format("\n%s\t%s\t%s", k, type(v), v)
   end
   
   print(str)
   
   --
   
   print("\nstring.gmatch")
   
   local str = header
   local f = string.gmatch(txt, "()(%w+)=()([%w.]+)")
   local i = 0
   while true do
       i = i + 1
   	local t = { f() }
       if #t == 0 then break end
   
   	for k, v in ipairs(t) do
   		str = str .. string.format("\n%i-%s\t%s\t%s", i, k, type(v), v)
   	end
   end
   
   print(str)

   string.match

   i	type	matched text
   1	number	1
   2	string	name
   3	number	6
   4	string	steve

   string.gmatch

   i	type	matched text
   1-1	number	1
   1-2	string	name
   1-3	number	6
   1-4	string	steve
   2-1	number	12
   2-2	string	color
   2-3	number	18
   2-4	string	blue

   I'll take a look at this in a bit. If only we could append ... for variadic returns like fun(): string|integer... for gmatch.
3. carsakiller

   added

   feat/LuaCats AnnotationsRelated to Lua Language Server Annotations (LuaCats)Related to Lua Language Server Annotations (LuaCats)

   on Feb 26, 2026
4. carsakiller

   self-assigned this

   on Feb 27, 2026
5. carsakiller

   added a commit that references this issue on Feb 27, 2026

   add LuaLS#3357 fix to changelog

   ca4bd21
6. sumneko

   closed this as completedin #3362on Jun 24, 2026