BLML

tArgs={ ... }

term.setCursorPos(1, 1)
term.clear()
print("BLML [ BasicLuaMadeLanguage ]\n")

symbols={}
functions = {}

local __THIS={}
__THIS.TERM=false

local function openFile(file)
    local f=fs.open(file, "r")
    local __str=f.readAll()
    f.close()
    return __str
end

local function append(tokens)
    local __str="[ "
    for n, v in pairs(tokens) do
        __str=__str..n.." = "..v..", "
    end
    __str=__str.."]"
    return __str
end

local function doASSIGN(varName, varValue)
    local __varNm=varName:sub(5)
    if __varNm:len()>=2 then
        symbols[__varNm]=varValue
    else
        error("Cant define the variable.")
        __THIS.TERM=true
    end
end

local function getVARIABLE(varName)
    local __VAR=varName:sub(5)
    if symbols[__VAR] and __VAR:len()>=1 then
        return symbols[varName:sub(5)]
    else
        __THIS.TERM=true
        error("Cant print BLANK/NOT ASSIGNED variables.")
    end
end

local function getINPUT(str, varName)
    local __str=str:sub(2, str:len()-1)
    write(__str)
    local inp=read()
    symbols[varName]=inp
end

local function parse(tokens)
    local i=1
    local __parseBelowCount=1
    while i <= #tokens and __THIS.TERM==false do
        if __parseBelowCount==1 then
            if tokens[i]=="END" then
                i=i+1
            elseif tokens[i]..tokens[i+1]:sub(1,6)=="PRINTSTRING" or tokens[i]..tokens[i+1]:sub(1,3)=="PRINTNUM" or tokens[i]..tokens[i+1]:sub(1,4)=="PRINTEXPR" or tokens[i]..tokens[i+1]:sub(1,3)=="PRINTVAR" then
                if tokens[i+1]:sub(1, 6) == "STRING" then
                    print(tokens[i+1]:sub(9, tokens[i+1]:len()-1))
                elseif tokens[i+1]:sub(1, 3) == "NUM" then
                    print(tokens[i+1]:sub(5))
                elseif tokens[i+1]:sub(1, 4) == "EXPR" then
                    print(loadstring("return "..tokens[i+1]:sub(6))())
                elseif tokens[i+1]:sub(1, 3) == "VAR" then
                    print(getVARIABLE(tokens[i+1]))
                end
                i=i+2
            elseif tokens[i]:sub(1, 3)..tokens[i+1]..tokens[i+2]:sub(1, 6)=="VAREQUALSSTRING" or tokens[i]:sub(1, 3)..tokens[i+1]..tokens[i+2]:sub(1, 3)=="VAREQUALSNUM" or tokens[i]:sub(1, 3)..tokens[i+1]..tokens[i+2]:sub(1, 4)=="VAREQUALSEXPR" or tokens[i]:sub(1, 3)..tokens[i+1]..tokens[i+2]:sub(1, 3)=="VAREQUALSVAR" then
                if tokens[i+2]:sub(1, 6) == "STRING" then
                    doASSIGN(tokens[i], tokens[i+2]:sub(9, tokens[i+2]:len()-1))
                elseif tokens[i+2]:sub(1, 3) == "NUM" then
                    doASSIGN(tokens[i], tokens[i+2]:sub(5))
                elseif tokens[i+2]:sub(1, 4) == "EXPR" then
                    local __retStr=tokens[i+2]:sub(6)
                    doASSIGN(tokens[i], loadstring("return "..__retStr)())
                elseif tokens[i+2]:sub(1, 3) == "VAR" then
                    doASSIGN(tokens[i], getVARIABLE(tokens[i+2]))
                end
                i=i+3
            elseif tokens[i]..tokens[i+1]:sub(1, 6)..tokens[i+2]:sub(1, 3)=="INPUTSTRINGVAR" then
                getINPUT(tokens[i+1]:sub(8), tokens[i+2]:sub(5))
                i=i+3
            elseif tokens[i]..tokens[i+1]:sub(1, 3)..tokens[i+2]..tokens[i+3]:sub(1, 3)..tokens[i+4]=="IFNUMEQEQNUMTHEN" then
                if not (tokens[i+1]:sub(5) == tokens[i+3]:sub(5)) then
                    __parseBelowCount=__parseBelowCount+1
                end
                i=i+5
            elseif tokens[i]..tokens[i+1]:sub(1, 3)..tokens[i+2]..tokens[i+3]:sub(1, 3)..tokens[i+4]=="IFVAREQEQNUMTHEN" then
                if not (getVARIABLE(tokens[i+1]) == tokens[i+3]:sub(5)) then
                    __parseBelowCount=__parseBelowCount+1
                end
                i=i+5
            end
        elseif __parseBelowCount>1 then
            if tokens[i] == "IF" then
                __parseBelowCount=__parseBelowCount+1
            end
            if tokens[i] == "END" then
                i=i+1
                __parseBelowCount=__parseBelowCount-1
            else
                i=i+1
            end
        end
    end
    print(append(symbols))
end

local function lex(filecontents)
    local tok=""
    local state=0
    local varStarted=0
    local expr=""
    local var=""
    local __str=""
    local isexpr=0
    local tokens={}
    local n = ""
    for i=1, #filecontents do
        char = filecontents:sub(i, i)
        tok = tok..char
        if tok==" " then
            if state==0 then
                tok=""
            else
                tok=" "
            end
        elseif tok=="\n" or tok=="<EOF>" then
            if #expr>0 and isexpr==1 then
                tokens[#tokens+1]="EXPR:"..expr
                expr=""
                isexpr=0
            elseif #expr>0 and isexpr==0 then
                tokens[#tokens+1]="NUM:"..expr
                expr=""
            elseif #var>0 then
                tokens[#tokens+1]="VAR:"..var
                var = ""
                varStarted=0
            end
            tok=""
        elseif tok=="=" and state==0 then
            if #expr>0 and isexpr==0 then
                tokens[#tokens+1]="NUM:"..expr
                expr=""
            end
            if #var>0 then
                tokens[#tokens+1]="VAR:"..var
                var = ""
                varStarted=0
            end
            if tokens[#tokens] == "EQUALS" then
                tokens[#tokens]="EQEQ"
            else
                tokens[#tokens+1]="EQUALS"
            end
            tok=""
        elseif tok=="$" and state==0 then
            varStarted=1
            var = var..tok
            tok=""
        elseif varStarted==1 then
            if tok=="<" or tok==">" then
                if #var>0 then
                    tokens[#tokens+1]="VAR:"..var
                    var = ""
                    varStarted=0
                end
            end
            var=var..tok
            tok=""
        elseif tok=="print" or tok=="PRINT" then
            tokens[#tokens+1]="PRINT"
            tok=""
        elseif tok=="INPUT" or tok=="input" then
            tokens[#tokens+1]="INPUT"
            tok=""
        elseif tok=="THEN" or tok=="then" then
            if #expr>0 and isexpr==0 then
                tokens[#tokens+1]="NUM:"..expr
                expr=""
            end
            if #var>0 then
                tokens[#tokens+1]="VAR:"..var
                var = ""
                varStarted=0
            end
            tokens[#tokens+1]="THEN"
            tok=""
        elseif tok=="STOPIF" or tok=="stopif" then
            tokens[#tokens+1]="END"
            tok=""
        elseif tok=="IF" or tok=="if" then
            tokens[#tokens+1]="IF"
            tok=""
        elseif tok=="0" or tok=="1" or tok=="2" or tok=="3" or tok=="4" or tok=="5" or tok=="6" or tok=="7" or tok=="8" or tok=="9" then
            expr=expr..tok
            tok=""
        elseif tok=="+" or tok=="-" or tok=="/" or tok=="*" or tok=="(" or tok==")" or tok=="%" then
            isexpr=1
            expr=expr..tok
            tok=""
        elseif tok=="\t" then
            tok=""
        elseif tok=="\"" or tok==" \"" then
            if state==0 then
                state=1
            elseif state==1 then
                tokens[#tokens+1]="STRING:"..__str.."\""
                __str=""
                state=0
                tok=""
            end
        elseif state==1 then
            __str=__str..tok
            tok=""
        end
    end
    --print(append(tokens))
    return tokens
    --return ""
end

local function main()
    local content=openFile(tArgs[1])
    content=content.."<EOF>"
    local toks=lex(content)
    parse(toks)
end

main()