Buffer API

-- Buffer API, By Symmetryc
return {
    new = function()
        return {
            act = {pos = {}};
            pos = {};
            back = colors.white;
            text = colors.lightGray;
            write = function(self, _str)
                local act = self.act
                local selfpos = self.pos
                local append = true
                if selfpos[1] ~= act.pos[1] or selfpos[2] ~= act.pos[2] then
                    act[#act + 1] = {term.setCursorPos, selfpos[1], selfpos[2]}
                    append = false
                end
                if self.back ~= act.back then
                    act[#act + 1] = {term.setBackgroundColor, self.back}
                    act.back = self.back
                    append = false
                end
                if self.text ~= act.text then
                    act[#act + 1] = {term.setTextColor, self.text}
                    act.text = self.text
                    append = false
                end
                for line, nl in _str:gmatch("([^\n]*)(\n?)") do
                    if append then
                        act[#act][2] = act[#act][2]..line
                        append = false
                    else
                        act[#act + 1] = {term.write, line}
                    end
                    selfpos[1] = selfpos[1] + #line
                    if nl == "\n" then
                        selfpos[1] = 1
                        selfpos[2] = selfpos[2] + 1
                        act[#act + 1] = {term.setCursorPos, 1, selfpos[2]}
                    end
                end
                act.pos = {selfpos[1], selfpos[2]}
                return self
            end;
            draw = function(self)
                for i, v in ipairs(self.act) do
                    if v[3] then
                        v[1](v[2], v[3])
                    else
                        v[1](v[2])
                    end
                end
                self.act = {}
                return self
            end;
        }
    end;
}