Module: Marshal

Defined in:: marshal.c

Constant Summary collapse

MAJOR_VERSION = major version

INT2FIX(MARSHAL_MAJOR)

MINOR_VERSION = minor version

INT2FIX(MARSHAL_MINOR)

Class Method Summary collapse

.dump(obj[, anIO], limit = -1) ⇒ Object

Serializes obj and all descendant objects.

Instance Method Summary collapse

#dump(obj[, anIO], limit = -1) ⇒ Object private

Serializes obj and all descendant objects.

Class Method Details

.dump(obj[, anIO], limit = -1) ⇒ `Object`

Serializes obj and all descendant objects. If anIO is specified, the serialized data will be written to it, otherwise the data will be returned as a String. If limit is specified, the traversal of subobjects will be limited to that depth. If limit is negative, no checking of depth will be performed.

class Klass
  def initialize(str)
    @str = str
  end
  def say_hello
    @str
  end
end

(produces no output)

o = Klass.new("hello\n")
data = Marshal.dump(o)
obj = Marshal.load(data)
obj.say_hello  #=> "hello\n"

Marshal can’t dump following objects:

anonymous Class/Module.
objects which are related to system (ex: Dir, File::Stat, IO, File, Socket and so on)
an instance of MatchData, Data, Method, UnboundMethod, Proc, Thread, ThreadGroup, Continuation
objects which define singleton methods

# File 'marshal.c', line 1156

static VALUE
marshal_dump(int argc, VALUE *argv, VALUE _)
{
    VALUE obj, port, a1, a2;
    int limit = -1;

    port = Qnil;
    rb_scan_args(argc, argv, "12", &obj, &a1, &a2);
    if (argc == 3) {
        if (!NIL_P(a2)) limit = NUM2INT(a2);
        if (NIL_P(a1)) io_needed();
        port = a1;
    }
    else if (argc == 2) {
        if (FIXNUM_P(a1)) limit = FIX2INT(a1);
        else if (NIL_P(a1)) io_needed();
        else port = a1;
    }
    return rb_marshal_dump_limited(obj, port, limit);
}

Instance Method Details

#dump(obj[, anIO], limit = -1) ⇒ `Object` (private)

class Klass
  def initialize(str)
    @str = str
  end
  def say_hello
    @str
  end
end