Reconstruction of String completely unsuccessful?

I highly don’t rely on anybody understanding the purpose or process of this function, so I’ll do my best to explain the piece I’d rather focus on. For those who have knowledge in String Patterns, this would probably be easy for you to grasp: I’m not sure if I’m just during stupid somewhere in the piece I’m having trouble with, or this truly is a problem, but what I’m trying to do here is cut off a piece from a String if it’s equivalent to anything In the array prohibited. I’m using a gmatch to iterate through the String’s words, I’m trying to accomplish stripping out something if it’s not entieraly just apart of the word; apart of another E.g. “Hello there”, then remove that chunk, it doesn’t seem to work, though if I had the prohibited word equal to the exact, then it would’ve been able to remove it perfectly fine. Yet it doesn’t function properly for both transactions now, what have I done wrong?

String = "Some sentence here I guess?"
local prohibited = {"I guess"} --// or “guess”
function rewrite(String)
   local reString = {}
   if (String:match("[%w%p]+")) then
      for a in String:gmatch("[^%s]+") do
         for _,b in next, prohibited do --// function begins here
            if (a:find(b) or String:find(b)) then
               a = String:gsub(b, "") or a:gsub(b, "")
               break
            end
         end
         table.insert(reString, a); --// ends here
      end
   else return "empty"
   end
   return table.concat(reString, " ")
end
local rewritedstring = rewrite(String) 
if (rewritedstring ~= "empty") then
   print("String: '"..rewritedstring.."' - ('"..String.."')")
else return end

--// function is supposed to return the String cleaned up with the prohibited word(s) removed, the String is return normal without the word(s) removed at all.

again, this is going to be incredibly hard to understand if you don’t have a good knowledge of String Patterns, or I’m dumb and there’s something obvious, gl?;)

Extraction of a single word is functional now

There seems to be a bit of unnecessary code in your snippet. Firstly, I wouldn't use a nested for. The same goal can be accomplished with only one numeric for loop.

####For example...

local blacklist = {"these", "are not"}

local function filterStringWithList(str, list)
	for i = 1, #list do
		str = string.gsub(str, list[i], "")
	end
	return string.gsub(str, "%s+", " ")
end

local filtered = filterStringWithList(
	"these words are not allowed", 
	blacklist
)

print(filtered)

words allowed

If I'm understanding your problem correctly, I believe this would be your desired outcome. Otherwise, let me know if I misunderstood.

Other Things I've Noticed:

• I'm not quite sure what purpose returning "empty" serves in your conditional situation.

• In the nested for, I believe you may be breaking out of the loop prematurely.

• Some of the string patterns can be simplified (e.g. [^%s]+ to %S, etc).

The logical operations on line 8 are also redundant; if a:find(b) is true then String:find(b) will always be false unless a and b are the same (in which case the or is still unnecessary).

All in all, I'd recommend a code clean-up. Clean code goes a long way in debugging a program. Try to simplify the concept as much as possible, then take a wack at the code.

Disclaimer

I'm proposing my code snippet above as a solution to your problem, but I'm still not quite sure if it still meets your criteria. If this wasn't what you were looking for, leave a comment describing how so and I will try to update my answer accordingly! Hope this helps!