diff --git a/plugins/ruby/codegen.pl b/plugins/ruby/codegen.pl
index a406cb758..1baa15365 100755
--- a/plugins/ruby/codegen.pl
+++ b/plugins/ruby/codegen.pl
@@ -51,8 +51,7 @@ sub render_global_enum {
     my ($name, $type) = @_;
 
     my $rbname = rb_ucase($name);
-    # store constants in DFHack::EnumName and not in DFHack::MemHack::EnumName
-    push @lines_rb, "class ::DFHack::$rbname";
+    push @lines_rb, "class $rbname";
     %seen_enum_name = ();
     indent_rb {
         render_enum_fields($type);
@@ -81,7 +80,7 @@ sub render_global_bitfield {
     my ($name, $type) = @_;
 
     my $rbname = rb_ucase($name);
-    push @lines_rb, "class $rbname < Compound";
+    push @lines_rb, "class $rbname < MemHack::Compound";
     indent_rb {
         render_bitfield_fields($type);
     };
@@ -142,7 +141,7 @@ sub render_global_class {
         }
     }
 
-    my $rbparent = ($parent ? rb_ucase($parent) : 'Compound');
+    my $rbparent = ($parent ? rb_ucase($parent) : 'MemHack::Compound');
 
     my $cppvar = "v_$cpp_var_counter";
     $cpp_var_counter++;
@@ -191,7 +190,7 @@ sub render_global_objects {
     push @lines_cpp, "void cpp_$sname(FILE *fout) {";
     push @include_cpp, $sname;
 
-    push @lines_rb, "class $rbname < Compound";
+    push @lines_rb, "class $rbname < MemHack::Compound";
     indent_rb {
         for my $obj (@objects) {
             my $oname = $obj->getAttribute('name');
@@ -208,7 +207,6 @@ sub render_global_objects {
     };
     push @lines_rb, "end";
 
-    push @lines_rb, "module ::DFHack";
     indent_rb {
         push @lines_rb, "Global = GlobalObjects.new._at(0)";
         for my $obj (@global_objects) {
@@ -216,7 +214,6 @@ sub render_global_objects {
             push @lines_rb, "def self.$obj=(v) ; Global.$obj = v ; end";
         }
     };
-    push @lines_rb, "end";
 }
 
 
@@ -325,8 +322,13 @@ sub render_item_pointer {
     my ($item, $cppvar) = @_;
 
     my $tg = $item->findnodes('child::ld:item')->[0];
-    my $tglen = get_tglen($tg, $cppvar);
-    push @lines_rb, "pointer($tglen) {";
+    my $ary = $item->getAttribute('is-array');
+    if ($ary and $ary eq 'true') {
+        my $tglen = get_tglen($tg, $cppvar);
+        push @lines_rb, "pointer_ary($tglen) {";
+    } else {
+        push @lines_rb, "pointer {";
+    }
     indent_rb {
         render_item($tg, "${cppvar}[0]");
     };
@@ -468,15 +470,13 @@ if ($output =~ /\.cpp$/) {
     print FH "}\n";
 
 } else {
-    print FH "module DFHack\n";
-    print FH "module MemHack\n";
     if ($memstruct) {
         open MH, "<$memstruct";
         print FH "$_" while(<MH>);
         close MH;
     }
+    print FH "module DFHack\n";
     print FH "$_\n" for @lines_rb;
     print FH "end\n";
-    print FH "end\n";
 }
 close FH;
diff --git a/plugins/ruby/ruby-memstruct.rb b/plugins/ruby/ruby-memstruct.rb
index 465e9975e..f4796edef 100644
--- a/plugins/ruby/ruby-memstruct.rb
+++ b/plugins/ruby/ruby-memstruct.rb
@@ -1,6 +1,8 @@
+module DFHack
+module MemHack
 class MemStruct
 	attr_accessor :_memaddr
-	def _at(addr) ; @_memaddr = addr ; self ; end
+	def _at(addr) ; @_memaddr = addr ; dup ; end
 	def _get ; self ; end
 end
 
@@ -27,8 +29,11 @@ class Compound < MemStruct
 		def bits(shift, len)
 			BitField.new(shift, len)
 		end
-		def pointer(tglen=nil)
-			Pointer.new(tglen, (yield if tglen))
+		def pointer
+			Pointer.new((yield if block_given?))
+		end
+		def pointer_ary(tglen)
+			PointerAry.new(tglen, yield)
 		end
 		def static_array(len, tglen)
 			StaticArray.new(tglen, len, yield)
@@ -80,6 +85,7 @@ class Compound < MemStruct
 	end
 	def _set(h) ; h.each { |k, v| send("_#{k}=", v) } ; end
 end
+
 class Number < MemStruct
 	attr_accessor :_bits, :_signed
 	def initialize(bits, signed)
@@ -149,6 +155,23 @@ class BitField < MemStruct
 end
 
 class Pointer < MemStruct
+	attr_accessor :_tg
+	def initialize(tg)
+		@_tg = tg
+	end
+
+	def _getp
+		DFHack.memory_read_int32(@_memaddr) & 0xffffffff
+	end
+
+	# the pointer is invisible, forward all methods to the pointed object
+	def method_missing(*a)
+		addr = _getp
+		tg = (addr == 0 ? nil : @_tg._at(addr)._get)
+		tg.send(*a)
+	end
+end
+class PointerAry < MemStruct
 	attr_accessor :_tglen, :_tg
 	def initialize(tglen, tg)
 		@_tglen = tglen
@@ -159,10 +182,6 @@ class Pointer < MemStruct
 		delta = (i != 0 ? i*@_tglen : 0)
 		(DFHack.memory_read_int32(@_memaddr) & 0xffffffff) + delta
 	end
-	def _setp(v)
-		DFHack.memory_write_int32(@_memaddr, v)
-	end
-	def _get ; self ; end
 
 	def [](i)
 		addr = _getp(i)
@@ -174,11 +193,6 @@ class Pointer < MemStruct
 		raise 'null pointer' if addr == 0
 		@_tg._at(addr)._set(v)
 	end
-
-	# the pointer is invisible, forward all methods to the pointed object
-	def method_missing(*a)
-		self[0].send(*a)
-	end
 end
 class StaticArray < MemStruct
 	attr_accessor :_tglen, :_length, :_tg
@@ -205,7 +219,7 @@ class StaticArray < MemStruct
 	end
 
 	include Enumerable
-	def each; (0...length).each { |i| yield self[i] }; end
+	def each ; (0...length).each { |i| yield self[i] } ; end
 end
 class StaticString < MemStruct
 	attr_accessor :_length
@@ -274,8 +288,9 @@ class StlVector32 < MemStruct
 		end
 		v
 	end
+
 	include Enumerable
-	def each; (0...length).each { |i| yield self[i] }; end
+	def each ; (0...length).each { |i| yield self[i] } ; end
 end
 class StlVector16 < StlVector32
 	def length
@@ -346,19 +361,41 @@ class StlDeque < MemStruct
 		@_tglen = tglen
 		@_tg = tg
 	end
+	# TODO
 end
 
 class DfFlagarray < MemStruct
 	# TODO
 end
-class DfArray < MemStruct
+class DfArray < Compound
 	attr_accessor :_tglen, :_tg
 	def initialize(tglen, tg)
 		@_tglen = tglen
 		@_tg = tg
 	end
 
-	# TODO
+	field(:_length, 0) { number 32, false }
+	field(:_ptr, 4) { number 32, false }
+
+	def length ; _length ; end
+	def size ; _length ; end
+	def _tgat(i)
+		@_tg._at(_ptr + i*@_tglen) if i >= 0 and i < _length
+	end
+	def [](i)
+		i += _length if i < 0
+		_tgat(i)._get
+	end
+	def []=(i, v)
+		i += _length if i < 0
+		_tgat(i)._set(v)
+	end
+	def _set(a)
+		a.each_with_index { |v, i| self[i] = v }
+	end
+
+	include Enumerable
+	def each ; (0...length).each { |i| yield self[i] } ; end
 end
 class DfLinkedList < MemStruct
 	attr_accessor :_tg
@@ -373,33 +410,60 @@ class Global < MemStruct
 		@_glob = glob
 	end
 	def _at(addr)
-		g = DFHack::MemHack.const_get(@_glob)
-		g = DFHack.rtti_getclass(g, addr)
+		g = DFHack.const_get(@_glob)
+		g = DFHack.rtti_getclassat(g, addr)
 		g.new._at(addr)
 	end
 end
+end	# module MemHack
 
-module ::DFHack
-	def self.rtti_register(cname, cls)
-		@rtti_n2c ||= {}
-		@rtti_class ||= {}
-		@rtti_n2c[cname] = cls
-		@rtti_class[cls] = true
-	end
 
-	# return the ruby class to use for a given address if rtti info is available
-	def self.rtti_getclass(cls, addr)
-		@rtti_n2c ||= {}
-		@rtti_class ||= {}
-		if addr != 0 and @rtti_class[cls]
-			@rtti_n2c[rtti_readclassname(get_vtable_ptr(addr))] || cls
-		else
-			cls
-		end
+# cpp rtti name -> rb class
+@rtti_n2c = {}
+@rtti_c2n = {}
+
+# vtableptr -> cpp rtti name (cache)
+@rtti_n2v = {}
+@rtti_v2n = {}
+
+def self.rtti_n2c ; @rtti_n2c ; end
+def self.rtti_c2n ; @rtti_c2n ; end
+
+# register a ruby class with a cpp rtti class name
+def self.rtti_register(cname, cls)
+	@rtti_n2c[cname] = cls
+	@rtti_c2n[cls] = cname
+end
+
+# return the ruby class to use for the cpp object at address if rtti info is available
+def self.rtti_getclassat(cls, addr)
+	if addr != 0 and @rtti_c2n[cls]
+		# rtti info exist for class => cpp object has a vtable
+		@rtti_n2c[rtti_readclassname(get_vtable_ptr(addr))] || cls
+	else
+		cls
 	end
+end
 
-	def self.rtti_readclassname(vptr)
-		@rtti_v2n ||= {}
-		@rtti_v2n[vptr] ||= get_rtti_classname(vptr)
+# try to read the rtti classname from an object vtable pointer
+def self.rtti_readclassname(vptr)
+	unless n = @rtti_v2n[vptr]
+		n = @rtti_v2n[vptr] = get_rtti_classname(vptr)
+		@rtti_n2v[n] = vptr
 	end
+	n
 end
+
+# return the vtable pointer from the cpp rtti name
+def self.rtti_getvtable(cname)
+	unless v = @rtti_n2v[cname]
+		v = get_vtable(cname)
+		@rtti_n2v[cname] = v
+		@rtti_v2n[v] = cname if v != 0
+	end
+	v if v != 0
+end
+
+end
+
+
diff --git a/plugins/ruby/ruby.cpp b/plugins/ruby/ruby.cpp
index 0e28087de..0b0df486f 100644
--- a/plugins/ruby/ruby.cpp
+++ b/plugins/ruby/ruby.cpp
@@ -370,14 +370,12 @@ static VALUE rb_dfregister(VALUE self, VALUE name, VALUE descr)
 
 static VALUE rb_dfget_global_address(VALUE self, VALUE name)
 {
-    uint32_t addr = Core::getInstance().vinfo->getAddress(rb_string_value_ptr(&name));
-    return rb_uint2inum(addr);
+    return rb_uint2inum(Core::getInstance().vinfo->getAddress(rb_string_value_ptr(&name)));
 }
 
 static VALUE rb_dfget_vtable(VALUE self, VALUE name)
 {
-    uint32_t addr = (uint32_t)Core::getInstance().vinfo->getVTable(rb_string_value_ptr(&name));
-    return rb_uint2inum(addr);
+    return rb_uint2inum((uint32_t)Core::getInstance().vinfo->getVTable(rb_string_value_ptr(&name)));
 }
 
 // read the c++ class name from a vtable pointer, inspired from doReadClassName