NitrogenFingers Computer Craft grammar AI speatch using BDA

--[[
    BDA: Brain Damaged Algorithm
    A natural language parsing and attempting to creating program

    Written by: BigSHinyToys
    Modified by: NitrogenFingers 28/8/2012 (12:20am)
--]]

local winX, winY = term.getSize()
--Add your stop word lists here- they can be common subjects, participles, or any other grammatical
--feature you'd like to capture. Denote it with a single, lowercase character- this indicates it is a
--terminating symbol
local stopWords = {
    ["s"] = {"I", "you", "he", "she", "they", "we"};
    ["v"] = {"is", "are", "am", "can be", "like", "hate", "often", "will", "must", "should", "might"};
    ["a"] = {"and", "or", ", also", ", but", ", however", "like"};
}
--This list is of words that aren't stop words- they'll be added as you type them
local vocab = {}
local vcLength = 0

local savefile = "Grammerwords"
local convofile = "Grammerconvo"

local function saveTalk(sentence)
    local f = fs.open(convofile, "a")
    f.write(sentence.."\n")
    f.close()
end

local function save()
    local f = fs.open(savefile, "w")
    f.write(textutils.serialize(vocab))
    f.close()
end

if fs.exists(savefile) then
    local f = fs.open(savefile, "r")
    local save = textutils.unserialize(f.readAll())
    f.close()
    vocab = save
end

--Here you should have tables with capital letters, your non-terminating characters, that include
--all possible rules for your grammar. These tokens will in turn be selected and randomly replaced
--with one of the contents of the table.
--Note: AVOID INFINITE LOOPS: make sure every possible grammar has a terminating-only character string.
local grammar = {
    ["S"] = {"svW"},
    ["W"] = {"waW", "wasW", "w"}
}

function readWords()
    while true do
        local arg1, arg2 = os.pullEvent("new_line")

        if arg1 == "new_line" then
            local lastMatch = ""
            for match in string.gmatch(arg2, "[^ \t]+") do
                local stop = false
                for _,list in pairs(stopWords) do
                    for _,stopword in pairs(list) do
                        --If you want to be supersmart you can try to detect stop words and add them
                        --to your list here- try looking for "ly" for adverbs, "ing" for present tense verbs
                        --etc.
                        if match == stopword then
                            stop = true
                            break
                        end
                    end
                end

                if not stop then
                    --We handle linkages here
                    if not vocab[match] then
                        --I must admit I'm unsure how to get just the key in a table (there must be a way)
                        --Anyway I just include the word itself as the first value in the value table. Cheap and dusty.
                        vocab[match] = {match, ""}
                        --And of course because it's a string indexed value now it's not included in the array, or the length!
                        vcLength = vcLength+1
                    end

                    if lastMatch ~= "" then
                        table.insert(vocab[lastMatch], match)
                    end

                    lastMatch = match
                else
                    lastMatch = ""
                end

            end
        end

        local newGrammar = "S"
        local found = false
        --This randomly creates your grammar
        repeat
            found = false
            for k,v in pairs(grammar) do
                local f = string.find(newGrammar, k)
                if f then
                    newGrammar = string.gsub(newGrammar, k, v[math.random(1, #v)], 1)
                    found = true
                end
            end
        until not found

        --This then randomly replaces your grammar with actual words
        local newSentence = ""
        for i=1,#newGrammar do
            local token = string.sub(newGrammar, i, i)
            if token == "w" then
                --This is horribly messy- will fix when less tired!
                local chosenWord = math.random(1,vcLength)
                local i=1
                for k,_ in pairs(vocab) do
                    if i==chosenWord then
                        chosenWord = k
                        break
                    end
                    i=i+1
                end

                local chosenLink = vocab[chosenWord][math.random(2,#vocab[chosenWord])]
                if chosenLink ~= "" then chosenLink = chosenLink.." " end

                --Again cheap and dusty here, the extra space will make sentences look a bit ugly. Requires a little tweaking, but I'm to tired to fix right now.
                newSentence=newSentence..vocab[chosenWord][1].." "..chosenLink
            else
                local newstop = stopWords[token][math.random(1,#stopWords[token])]
                --Cheap and dusty (lots of it in this program!) to get rid of extra space
                if string.sub(newstop, 1, 1)=="," then newSentence = string.sub(newSentence, 1, #newSentence-1) end
                newSentence=newSentence..newstop.." "
            end
        end
        term.scroll(1)
        term.setCursorPos(1,winY - 1)
        term.clearLine()
        save()
        local talk = "AI> "..string.sub(newSentence, 1, #newSentence-1).."."
        saveTalk(talk)
        print(talk)
    end
end

function getInput()
    while true do
        term.setCursorPos(1,winY)
        term.clearLine()
        local input = read()
        saveTalk(input)
        os.queueEvent("new_line",input)
    end
end

term.clear()
parallel.waitForAny(getInput, readWords)