[pypy-svn] pypy documentation-cleanup: this file is still useful in case someone wants to implement rpython-jvm bindings; make it up to date by removing all references to the new deatch js backend

[antocuni]

Author: Antonio Cuni <anto.cuni at gmail.com>
Branch: documentation-cleanup
Changeset: r43661:ba54e7d7fbe6
Date: 2011-04-27 12:33 +0200
http://bitbucket.org/pypy/pypy/changeset/ba54e7d7fbe6/

Log:	this file is still useful in case someone wants to implement
	rpython-jvm bindings; make it up to date by removing all references
	to the new deatch js backend

diff --git a/pypy/doc/discussion/outline-external-ootype.rst b/pypy/doc/discussion/outline-external-ootype.rst
--- a/pypy/doc/discussion/outline-external-ootype.rst
+++ b/pypy/doc/discussion/outline-external-ootype.rst
@@ -1,24 +1,10 @@
-.. XXX, anto, can this be killed?
-
 Some discussion about external objects in ootype
 ================================================
 
-Current approaches:
-
-* BasicExternal, used for js backend
+Current approach:
 
 * SomeCliXxx for .NET backend
 
-BasicExternal
--------------
-
-* Is using types to make rpython happy (ie, every single method or field
-  is hardcoded)
-
-* Supports callbacks by SomeGenericCallable
-
-* Supports fields, also with callable fields
-
 SomeCliXxx
 ----------
 
@@ -28,11 +14,11 @@
 
 * Supports static methods
 
-Would be extremely cool to have just one approach instead of two,
-so here are some notes:
+Would be extremely cool to generalize the approach to be useful also for the
+JVM backend.  Here are some notes:
 
 * There should be one mechanism, factored out nicely out of any backend,
-  to support any possible backend (cli, js, jvm for now).
+  to support any possible backend (cli, jvm for now).
 
 * This approach might be eventually extended by a backend itself, but
   as much as possible code should be factored out.
@@ -48,24 +34,22 @@
 ================================
 
 The goal of the task is to let RPython program access "external
-objects" which are available in the target platform; these include:
+entities" which are available in the target platform; these include:
 
   - external classes (e.g. for .NET: System.Collections.ArrayList)
 
-  - external instances (e.g. for js: window, window.document)
+  - external prebuilt instances (e.g. for .NET: typeof(System.Console))
 
-  - external functions? (they are not needed for .NET and JVM, maybe
-    for js?)
-
-External objects should behave as much as possible as "internal
-objects".
+External entities should behave as much as possible as "internal
+entities".
 
 Moreover, we want to preserve the possibility of *testing* RPython
 programs on top of CPython if possible. For example, it should be
 possible to RPython programs using .NET external objects using
-PythonNet; probably there is something similar for JVM, but not for
-JS as I know.
+PythonNet; for JVM, there are JPype_ and JTool_, to be investigated:
 
+.. _JPype: http://jpype.sourceforge.net/
+.. _JTool: http://wiki.europython.eu/Talks/Jtool%20Java%20In%20The%20Python%20Vm
 
 How to represent types
 ----------------------
@@ -126,11 +110,6 @@
 and JVM the job can be easily automatized, since the objects have got
 precise signatures.
 
-For JS, signatures must be written by hand, so we must provide a
-convenient syntax for it; I think it should be possible to use the
-current syntax and write a tool which translates it to low-level
-types.
-
 
 RPython interface
 -----------------
@@ -148,9 +127,8 @@
   - access to static methods: return an object which will be annotated
     as SomeExternalStaticMeth.
 
-Instances are annotated as SomeExternalInstance. Prebuilt external
-objects (such as JS's window.document) are annotated as
-SomeExternalInstance(const=...).
+Instances are annotated as SomeExternalInstance. Prebuilt external objects are
+annotated as SomeExternalInstance(const=...).
 
 Open issues
 -----------
@@ -181,18 +159,12 @@
 It would be nice to allow programmers to inherit from an external
 class. Not sure about the implications, though.
 
-Callbacks
-~~~~~~~~~
-
-I know that they are an issue for JS, but I don't know how they are
-currently implemented.
-
 Special methods/properties
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 In .NET there are special methods that can be accessed using a special
 syntax, for example indexer or properties. It would be nice to have in
-RPython the same syntax as C#.
+RPython the same syntax as C#, although we can live without that.
 
 
 Implementation details