sl.lua

stack = {
    memory = {};

    push = function(self, number)
        table.insert(self.memory, number)
    end;

    pop = function(self)
        if #self.memory > 0 then
            local temp = self.memory[#self.memory]
            table.remove(self.memory, #self.memory)
            return temp
        else
            print "Ошибка: стек пуст!"
            error()
        end
    end;

    print_memory = function(self)
        if #self.memory > 0 then
            for key, value in pairs(self.memory) do
                print(key, value)
            end
        else
            print "Ошибка: невозможно вывести содержимое стека, так как стек пуст!"
            error()
        end
    end;
}

dictionary = {
    [""] = function()
    end;

    ["quit"] = function()
        parser.working = false
    end;

    ["+"] = function()
        local op1 = stack:pop()
        local op2 = stack:pop()
        stack:push(op2 + op1)
    end;

    ["-"] = function()
        local op1 = stack:pop()
        local op2 = stack:pop()
        stack:push(op2 - op1)
    end;

    ["*"] = function()
        local op1 = stack:pop()
        local op2 = stack:pop()
        stack:push(op2 * op1)
    end;

    ["/"] = function()
        local op1 = stack:pop()
        local op2 = stack:pop()
        stack:push(op2 / op1)
    end;

    ["^"] = function()
        local op1 = stack:pop()
        local op2 = stack:pop()
        stack:push(op2 ^ op1)
    end;

    ["sqrt"] = function()
        stack:push(math.sqrt(stack:pop()))
    end;

    ["negate"] = function()
        stack:push(stack:pop() * -1)
    end;

    ["and"] = function()
        local op1 = stack:pop()
        local op2 = stack:pop()
        stack:push(op2 and op1)
    end;

    ["or"] = function()
        local op1 = stack:pop()
        local op2 = stack:pop()
        stack:push(op2 or op1)
    end;

    ["not"] = function()
        stack:push(not stack:pop())
    end;

    ["=="] = function()
        local op1 = stack:pop()
        local op2 = stack:pop()
        stack:push(op2 == op1)
    end;

    [">"] = function()
        local op1 = stack:pop()
        local op2 = stack:pop()
        stack:push(op2 > op1)
    end;

    ["<"] = function()
        local op1 = stack:pop()
        local op2 = stack:pop()
        stack:push(op2 < op1)
    end;

    [">="] = function()
        local op1 = stack:pop()
        local op2 = stack:pop()
        stack:push(op2 >= op1)
    end;

    ["<="] = function()
        local op1 = stack:pop()
        local op2 = stack:pop()
        stack:push(op2 <= op1)
    end;

    ["=/="] = function()
        local op1 = stack:pop()
        local op2 = stack:pop()
        stack:push(op2 ~= op1)
    end;

    ["true"] = function()
        stack:push(true)
    end;

    ["false"] = function()
        stack:push(false)
    end;

    ["dup"] = function()
        local op1 = stack:pop()
        stack:push(op1)
        stack:push(op1)
    end;

    ["drop"] = function()
        stack:pop()
    end;

    ["swap"] = function()
        local op1 = stack:pop()
        local op2 = stack:pop()
        stack:push(op1)
        stack:push(op2)
    end;

    ["print"] = function()
        print(stack:pop())
    end;
}

parser = {
    str = "";

    working = true;

    words = {};

    is_number = function(str)
        if string.sub(str, 1, 1) == "+" or string.sub(str, 1, 1) == "-" then
            if tonumber(string.sub(str, 2, 2)) ~= nil then
                return true
            else
                return false
            end
        else
            if tonumber(string.sub(str, 1, 1)) ~= nil then
                return true
            else
                return false
            end
        end
    end;

    is_in_dictionary = function(word)
        for key, _ in pairs(dictionary) do
            if key == word then
                return true
            end
        end
        return false
    end;

    read_string = function(self)
        local temp
        io.write("]")
        temp = io.read()
        if string.sub(temp, #temp, #temp) ~= ":" then
            self.str = temp
        else
            self.str = ""
            temp = string.sub(temp, 1, #temp-1)
            while string.sub(temp, #temp, #temp) ~= ";" do
                self.str = self.str .. " " .. temp
                io.write("]]")
                temp = io.read()
            end
            self.str = self.str .. " " .. string.sub(temp, 1, #temp-1)
        end
    end;

    split = function(self)
        function current_char(pos)
            return string.sub(self.str, pos, pos)
        end

        self.words = {}
        local i = 1
        local start_point = 1

        while i <= string.len(self.str) do
            while current_char(i) == " " or current_char(i) == "(" or current_char(i) == ")" do
                i = i + 1
            end

            if current_char(i) == "'" then
                start_pos = i
                i = i + 1
                while current_char(i) ~= "'" do
                    if i < string.len(self.str) then
                        i = i + 1
                    else
                        print "Ошибка: не найден конец строки. Не хватает парной одинарной кавычки!"
                        error()
                    end
                end
                table.insert(self.words, string.sub(self.str, start_pos, i))
                i = i + 1

            elseif current_char(i) == '"' then
                start_pos = i
                i = i + 1
                while current_char(i) ~= '"' do
                    if i < string.len(self.str) then
                        i = i + 1
                    else
                        print "Ошибка: не найден конец строки. Не хватает парной кавычки!"
                        error()
                    end
                end
                table.insert(self.words, string.sub(self.str, start_pos, i))
                i = i + 1

            elseif current_char(i) == "|" then
                i = i + 1
                while current_char(i) ~= "|"  do
                    if i < string.len(self.str) then
                        i = i + 1
                    else
                        print "Ошибка: не найден конец комментария. Не хватает символа конца комментария!"
                        error()
                    end
                end
                i = i + 1

            else
                start_pos = i
                while current_char(i) ~= " " and current_char(i) ~= "|" and current_char(i) ~= "(" and current_char(i) ~= ")" and i <= string.len(self.str) do
                    i = i + 1
                end
                table.insert(self.words, string.sub(self.str, start_pos, i-1))
            end
        end
    end;

    execute_words = function(self)
        for i, word in pairs(self.words) do
            if self.is_number(word) then
                stack:push(tonumber(word))

            elseif string.sub(word, 1, 1) == "'" or string.sub(word, 1, 1) == '"' then
                stack:push(string.sub(word, 2, #word-1))

            else
                --if word ~= nil then       -- НЕ ТРОГАТЬ!!! ТУТ КАКАЯ-ТО МАГИЯ!!!
                if self.is_in_dictionary(word) then
                    dictionary[word]()
                else
                    print("Ошибка: слово ".. word .. " не найдено в словаре!")
                    error()
                end
                --end
            end
        end
    end;
}

function main()
    while parser.working do
        parser:read_string()
        parser:split()
        parser:execute_words()
    end
end

main()