Wednesday, June 17, 2009

Eliza expands its mind

I have looked at many Eliza implementations and most only match a single word in the sentence, or a word in the middle and the rest after the match, so I took it a bit further, I can now match stuff like: "I %% flowers **" and also stuff like "I %% and %% flowers **". This would catch several multi-word patterns in between and whatever goes behind flowers. Given that Eliza does pattern matching but the humans employ several words for the same thing if only your Eliza could group by similarities for example by ["love","like","fond of","don't hate","don't dislike"] . Another example: how many Elizas can tell that these are equivalent to a human: ["MAC", "MACs", "Macs", "Mac", "Macintosh", "mac", "macintosh", "apple", "Apple", "Macbook", "mac mini", "Macmini"] ?? So how do you catch different ways of expressing tastes with different nouns, that tell you more or less the same thing ??

Answer: pattern expansion !! I expanded Eliza's linguistic abilities to match similar patterns, you only need to create a pattern list of synonyms and specify that list in another pattern as an expansion pattern like "I ## ##" where ## stands for the synonym list, here is how:

To recreate the above example you would create 3 records in the Eliza file, the first is the pattern and the other 2 are merely variables.

{["I ## ## **"],
["I live inside a computer","I can live inside a Mac","Maybe I reside in a Mac right now"],
{subject,computers,["##1", "##2"],["like","Mac"],[]}},
{["##1"], ["love", "like", "fond of", "don't hate", "don't dislike"], {internal,synonyms,[],[],[]}},
["MAC","MACs", "Macs", "Mac", "Macintosh", "mac", "macintosh", "apple", "Apple", "Macbook", "Ibook", "Macmini"],

So now the pattern "I ## ##" is expanded against both variables
["##1", "##2"]. which creates in this case 150 patterns in run-time, but your file only required a simple entry and again Eliza returns some values that your AI can now chew on. Those variables can obviously be reused in other patterns and it's needless to say that I will be able to teach her new stuff in run-time.

Things that I find are still needed be it either on Eliza's or the AI's side is to catch specifically nouns and verbs, maybe by matching against another list and trying to find a corresponding context for them, like when your application knows nothing about flowers, but flowers are plants and maybe your AI knows something about plants or maybe it lacks info on Mac's but knows about computers. And Eliza should also be able to ask the user and remember its question
. But for the time being, I am quite happy with the implementation, it will suit SMASH well to have NPCs that the user can actually talk to. The current version is stand alone, future ones will likely put their info on KVS* for easy data access and replication.



Saturday, June 13, 2009

Eliza speaks Erlang with a twist

As I said in the previous post, Eliza should be fairly easy to implement in Erlang and so it was, I present to you the first Eliza that speaks Erlang:

The image on the left shows the Erlang Shell where you can see some examples of Eliza being called as eliza:start(Text) [also possible: eliza:start(Text, Bot) (not shown) to choose some kind of personality]. Eliza will try to load its text file for interpretation from disk.
Eliza prints
out in the shell and returns a tuple with: the input string, context information, extra words from the pattern matching and the answer from Eliza.

What for ??
A normal Eliza implementation has no idea what you are talking about, it does no provide or save the context of the conversation, so my implementation has a little twist, you can provide some additional info to each question-answer list, meant to be used by an AI implementation, so like above when stating your name, Eliza answers with {name,player} and the player name, so your AI could register that Eliza just got the player's name or whatever the player tells Eliza, like dislikes, likes, emotions, hobbies or whatever, your AI could then save the data to a database or you could also load a different Bot context file to chat more specifically on a topic. I will incorporate this in my AI modules in the future and in the meanwhile this will serve for some "dump" entertainment in SMASH. A miniature dictionary to showcase Eliza is included in the code. I also see a use for this on the CNPC's to detect automatically abusive or foul language, as mentioned on many previous posts.

If there is anybody interested in the code, let me know and I'll publish it here on the Blog, it's deceptively simple, just under 200 lines and not yet optimized, but it's a first step towards implementing AI in Erlang.

And now back to CAM.



Tuesday, June 9, 2009

Huh ?? Did you SAY something ??

As CAM goes forward, I am defining user permissions, channel permissions, guild structures and user levels which go from guest to game developer with each level having unique commands, which of course brings us to the point of what the final command structure will look like, I believe it's going to be something like: {CHANNEL:REQ:PARAMS} where each REQ that comes from the socket is seen as a request for action by the CC component before being sent to its Action handler (AH) and from there to the channel controlling NPC (let's call it CNPC for future reference). Only the CNPC's can return commands that need to be applied to each CC. Some commands will need to take into account distances, which will be done in the CC, commands like "SAY", movement and position data or Area of Effect spells, Thor gives in his book an example on how to do that kind of calculation easily and without spending much on calculations. Apocalyx will need to translate the server packages from {CHANNEL:WHO:{CMD1:PARAMS}{CMD2:PARAMS}{CMD3:PARAMS}} into action on the client and WHO is obviously derived from the CC.

Note to self: Commands are better off as binary structures or at least send the commands list with a number to the client and have the client use a number to shorten sent IP packets. Maybe SOX will translate and package this at some point into a binary format.

Once again I find that prototyping takes so much longer than actual coding, because it really pays off to think before you program and avoid conventional code at all cost !! Erlang rewards those who create the application logic by pattern matching.

Which reminds me, a nice little Eliza implementation for a CNPC might be fun to start with, for those who don't know Eliza, it was invented as a program that would apparently answer with AI to a sentence by analyzing the sentence structure, recognizing certain words and answer with premanufactured phrases, making people think they were talking to a person, well, in the 70's it was surprising, that is. It's still fun though and with little modifications, KVS could provide a short term memory for Eliza to keep track of what users talked about. You may notice that pattern matching is precisely what makes Eliza strong ;) and hence should be trivial to implement in Erlang.

One last side note, I have not yet replaced Mnesia in SMASH given that I am still debugging KVS*.

That's all for now folks,


Monday, June 8, 2009

Tuples here, there and everywhere

As I am trying to make some progress on the authorization module, I find that the required databases are getting more and more complex and with them the record structure, meaning that tuple pattern matching is quickly becoming a logistical nightmare, stuff like {_,_,_,_,Variable,_,_,_,_,_,_,_,_,_,_,_,_} = Some_tuple is not very practical. Erlang has a native record definition, but it has some important restrictions, so I had to create a record structure for KVS2, that can correctly create, modify and read records in KVS2 by naming the fields, for this you need to create a list entry on the 2 DB structure tables. After that, you can simply call kvs2:crtrecord(DB,Key,Data), where DB is the table & table structure, Key is the record name and Data is a list of tuples of {field_name, Value}, you can read with getrecord(DB, Key, [Fields]) and modify an entry with updrecord(DB,Key,Data), which works similar to crtrecord, you only need to specify the fields that will be modified. This greatly simplifies data management and allows to change the database format in the future, too. You can also use this functionality to manage any kind of tuple with crttuple & updtuple. This should provide some more flexibility than native Erlang to manage structured tuples. With this addition KVS2 can now handle Key-Value pairs with structured value tuples.

This tuple management and the magical pattern matching will make authorizations ... almost ... a breeze.

BTW, for those of you who can already employ version R13, note that there is a new function called:
erlang:make_tuple(Arity, Default, InitList) which can create tuples with initial values, very nice addition, unfortunately Ubuntu has no support for R13 yet (unless I compile manually , yuk!), well, you can't have everything I guess.

Soon more on the Chat Authorization Module (CAM).