README.org: Update the roadmap.

README.org

@@ -34,36 +34,43 @@ interaction with Org-mode.
    that I work on the subsequent items decreases with their position
    in the list.
 
-*** TODO Think about /not/ using generics for the dynamics
-    Typed Racket can now type classes, and I can implement the idea
-    from the module =generics= as a class.  However, I got this advice
-    on Racket Users group:
-
-    #+BEGIN_QUOTE
-    If you don't need to support arbitrary user implementations, you
-    can avoid generics and classes altogether and use structs whose
-    fields contain functions.
-    #+END_QUOTE
-
-    I will need to think about simpler implementations of the
-    interface to dynamics, which should also be simpler to type.
-
 *** TODO Convert =dds= to Typed Racket
-    This will necessarily lead to updates in the comments, which
-    should be rewritten with Scribble.
+    Rewriting =dds= with Typed Racket will be a major refactoring,
+    consisting in the following 3 phases which will happen more or
+    less in parallel:
 
-    I will do the conversion in the directory =typed/=, by
-    incrementally translating existing modules, definition
-    by definition.
+    - define types, add type signatures, add types for functions
+      I import from =graph=;
+    - transfer the comments from the source files to Scribble
+      documentation;
+    - redefine the generic interface for dynamics, which is currently
+      in =generics=.
 
-    The order I will convert the modules:
+    I plan to implement the new dynamics interface as a classes, since
+    Typed Racket can now type classes.  I didn't really like generics:
+    they are quite cumbersome, and I think I can do more with classes.
+
+    People on Racket Users suggested using structures with fields
+    containing functions, but it does not seem to get me to my goal of
+    having type-level methods/functions.
+
+    The order in which I will convert the modules:
 
     1. =utils=
     2. =functions=
-    3. the module defining the interface to dynamics (currently =generics=)
+    3. =dynamics= (currently =generics=)
     4. =networks=
     5. =rs=
 
+    This is how I will convert a module =A=:
+
+    1. Create a copy =A-untyped.rkt=.
+    2. Empty =A.rkt=.
+    3. Transfer the definitions from =A-untyped.rkt= to =A.rkt= one by
+       one, adding the necessary types, signatures, and typed imports
+       as I go.
+    4. When done, remove =A-untyped.rkt=.
+
 *** TODO Split =networks= into general networks and threshold Boolean networks
 *** TODO Submit =update-graph= to =stchang=
 *** TODO Implement the BN \to RS conversion