The Eliza chatbot basically turns a message into a response But often asking the user to elaborate further. It is portrayed as a psychologist and originally written by a doctor in 1966 it uses pattern matching. The function has been ported to Luau by my and the function is simply this.
I corrected the grammar so it does not look like a terminal and ported this code from a old version of lua. I improved it by making answer mulitple sentences at once.
-- Joseph Weizenbaum's classic Eliza ported to Luau
-- Ported to Luau by Magus_ArtStudios, Original port Kein-Hong Man <khman@users.sf.net> 20060905
------------------------------------------------------------------------
-- Original ELIZA paper: ELIZA--A Computer Program For the Study of Natural Language
-- Joseph Weizenbaum, 1966, Communications of the ACM Volume 9,
-- URL: http://i5.nyu.edu/~mm64/x52.9265/january1966.html
------------------------------------------------------------------------
-- A copy of the original BASIC source of this Lua version of ELIZA can
-- be found at Josep Subirana's ELIZA download page.
------------------------------------------------------------------------
-- NOTES
--* Ported to Luau by Magus_ArtStudios 10/18/2023
-- * For historical accuracy, functionality is more-or-less identical,
------------------------------------------------------------------------
function Eliza(text)
local response = ""
local user = string.lower(text)
local userOrig = user
-- randomly selected replies if no keywords
local randReplies = {
"What does that suggest to you?",
"I see...",
"I'm not sure I understand you fully.",
"Can you elaborate on that?",
"That is quite interesting!",
"That's so... Please continue...",
"I understand...", "Well, well... Do go on",
"Why are you saying that?",
"Please explain the background to that remark...",
"Could you say that again, in a different way?",
}
local replies = {
[" can you"] = {"Perhaps you would like to be able to"},
[" do you"] = {"Yes, I"},
[" can i"] = {"Perhaps you don't want to be able to"},
[" you are"] = {"What makes you think I am"},
[" you're"] = {"What is your reaction to me being"},
[" i don't"] = {"Why don't you"},
[" i feel"] = {"Tell me more about feeling"},
[" why don't you"] = {"Why would you want me to"},
[" why can't i"] = {"What makes you think you should be able to"},
[" are you"] = {"Why are you interested in whether or not I am"},
[" i can't"] = {"How do you know you can't"},
[" i am"] = {"How long have you been"},
[" i'm"] = {"Why are you telling me you're"},
[" i want"] = {"Why do you want"},
[" what"] = {"What do you think?"},
[" how"] = {"What answer would please you the most?"},
[" who"] = {"How often do you think of such questions?"},
[" where"] = {"Why did you think of that?"},
[" when"] = {"What would your best friend say to that question?"},
[" why"] = {"What is it that you really want to know?"},
[" perhaps"] = {"You're not very firm on that!"},
[" drink"] = {"Moderation in all things should be the rule."},
[" sorry"] = {"Why are you apologizing?", "Please don't apologize",
"Apologies are not necessary",
"What feelings do you have when you apologize",},
[" dreams"] = {"Why did you bring up the subject of dreams?"},
[" i like"] = {"Is it good that you like"},
[" maybe"] = {"Aren't you being a bit tentative?"},
[" no"] = {"Why are you being negative?"},
[" your"] = {"Why are you concerned about my"},
[" always"] = {"Can you think of a specific example?"},
[" think"] = {"Do you doubt"},
[" yes"] = {"You seem quite certain. Why is this so?"},
[" friend"] = {"Why do you bring up the subject of friends?"},
[" am i"] = {"You are"},
[" i remember"]= {
"Do you often think of",
"What else do you remember?",
"Why do you recall",
"What in the present situation reminds you of",
"What is the connection between me and"
},
}
-- keywords, replies
-- conjugate
local conjugate = {
[" i "] = "you",
[" are "] = "am",
[" were "] = "was",
[" you "] = "me",
[" your "] = "my",
[" i've "] = "you've",
[" i'm "] = "you're",
[" me "] = "you",
[" am i "] = "you are",
[" am "] = "are",
}
local function createSentences(str)
local sentences = {} -- create an empty table to store the sentences
local start = 1 -- initialize the start index of the current sentence
for i = 1, #str do -- loop through each character in the input string
local c = str:sub(i, i) -- get the current character
if c == "!" or c == "?" or c == "." or i==#str then -- check if the current character is a punctuation mark
local sentence = str:sub(start, i) -- get the current sentence from the start index to the current index
table.insert(sentences, sentence) -- insert the current sentence into the table
start = i + 1 -- update the start index to the next character after the punctuation mark
end
end
if sentences[1]==nil then
return {str}
end
-- random replies, no keyword
return sentences -- return the table of sentences
end
local function processSentences(user,response)
-- find keyword, phrase
local function replyRandomly()
response = randReplies[math.random(#randReplies)]..""
end
local function processInput()
for keyword, reply in pairs(replies) do
local d, e = string.find(user, keyword, 1, 1)
if d then
-- process keywords
local chr=reply[math.random(1,#reply)]
response = response..chr.." "
if string.byte(string.sub(chr, -1)) < 65 then -- "A"
response = response..""; return
end
local h = string.len(user) - (d + string.len(keyword))
if h > 0 then
user = string.sub(user, -h)
end
for cFrom, cTo in pairs(conjugate) do
local f, g = string.find(user, cFrom, 1, 1)
if f then
local j = string.sub(user, 1, f - 1).." "..cTo
local z = string.len(user) - (f - 1) - string.len(cTo)
response = response..j..""
if z > 2 then
local l = string.sub(user, -(z - 2))
if not string.find(userOrig, l) then return end
end
if z > 2 then response = response..string.sub(user, -(z - 2)).."" end
if z < 2 then response = response.."" end
return
end--if f
end--for
response = response..user..""
return response
end--if d
end--for
replyRandomly()
return response
end
-- main()
-- accept user input
if string.sub(user, 1, 3) == "bye" then
response = "Bye, bye for now.See you again some time."
return response
end
if string.sub(user, 1, 7) == "because" then
user = string.sub(user, 8)
end
user = " "..user.." "
-- process input, print reply
processInput()
response = response..""
return response
end
local responsec=""
local responses={}
for i,v in pairs(createSentences(user)) do
local response=nil
local answ=processSentences(v," ")
if responses[answ]==nil then
print(responses)
responses[answ]=1
responsec=responsec..answ
end
end
return responsec
end
Here is an example of input to output by running this function with some input text with a module in the command prompt
cm=require(chatbotloc) print(cm.Eliza(" I remember picking flowers. Do you like picking flowers? Goodbye for now")) - Studio
What else do you remember? Why are you interested in whether or not I am like picking flowers? Why are you being negative?
For those interested this is the original Lua source code it was ported from!
https://lua-users.org/wiki/SciteElizaClassic
The way the responses seem to work is they are appended by the rest of the sentence with a direct key lookup table by processing the text. The responses with no punctuation at the end are appended by the users query following the key look up pattern.
If you art interested in using this in conjunction with a more advanced chatbot library check out this related resource! 
AI Chatbot Library [Open Source] Eliza, Emotion Awareness Emojis,Bag of Words,Previous/Next Word Predictor,Text Randomizer, Word Geometry+Math Solver - Resources / Community Resources - Developer Forum | Roblox
I updated the chatmodule resource and removes its dependencies. If you wish to test out my chatbot you can try it out here.