# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1232929530 -3600
# Node ID 168c6f68045d406a0d2252cb141f179a71764655
# Parent  831ab0ba3de61ba9b7cba1db5d45c60edf121e5a
Fixed the output representation of Block instances.
Added support for some native methods, changing the invocation mechanism to use
a special dictionary for mapping method names to method implementations.
Moved run-time constant initialisation into the RSVPMachine class.
Fixed the CheckException instruction, made _CheckInstance return a value, added
a _MakeObject method.
Added notes about the current solution for instance/class compatibility testing.

diff -r 831ab0ba3de6 -r 168c6f68045d docs/structures.txt
--- a/docs/structures.txt	Sun Jan 25 02:56:16 2009 +0100
+++ b/docs/structures.txt	Mon Jan 26 01:25:30 2009 +0100
@@ -273,6 +273,8 @@
 effectively be a matrix with each dimension indexed using the same sequence of
 codes for each of the classes in a program.
 
-An alternative might be to insert descendants as special attributes into the
-object/attribute lookup table. This would also require an extra key to be
-retained, since each class would have its own attribute code.
+The current solution is to insert descendants as special attributes into the
+object/attribute lookup table. This requires an extra key to be retained,
+since each class must provide its own attribute code such that upon an
+instance/class compatibility test, the code may be obtained and used in the
+object table.
diff -r 831ab0ba3de6 -r 168c6f68045d micropython/rsvp.py
--- a/micropython/rsvp.py	Sun Jan 25 02:56:16 2009 +0100
+++ b/micropython/rsvp.py	Mon Jan 26 01:25:30 2009 +0100
@@ -20,11 +20,12 @@
 """
 
 from micropython.data import Attr, Const
+from micropython.common import Block
 
 def name(attr):
     if isinstance(attr, Attr):
         return attr.name or "<unnamed>"
-    elif isinstance(attr, Const):
+    elif isinstance(attr, (Block, Const)):
         return attr
     else:
         return attr.full_name() or "<unnamed>"
diff -r 831ab0ba3de6 -r 168c6f68045d rsvp.py
--- a/rsvp.py	Sun Jan 25 02:56:16 2009 +0100
+++ b/rsvp.py	Mon Jan 26 01:25:30 2009 +0100
@@ -73,7 +73,7 @@
 
     "A really simple virtual processor."
 
-    def __init__(self, memory, objlist, paramlist, attr_error, type_error, pc=None, debug=0):
+    def __init__(self, memory, objlist, paramlist, pc=None, debug=0):
 
         """
         Initialise the processor with a 'memory' (a list of values containing
@@ -81,8 +81,8 @@
         """
 
         self.memory = memory
-        self.objlist = objlist
-        self.paramlist = paramlist
+        self.objlist = objlist.as_raw()
+        self.paramlist = paramlist.as_raw()
         self.pc = pc or 0
         self.debug = debug
 
@@ -109,8 +109,12 @@
 
         # Constants.
 
-        self.attr_error = attr_error
-        self.type_error = type_error
+        self.attr_error = objlist.access("__builtins__", "AttributeError").value.location
+        self.type_error = objlist.access("__builtins__", "TypeError").value.location
+
+        # Native class constants.
+
+        self.int_class = objlist.access("__builtins__", "int").value.location
 
     # Debugging methods.
 
@@ -280,8 +284,11 @@
         PC to 'next' afterwards; otherwise, set PC to 'addr'.
         """
 
+        # Trap library functions introduced through the use of strings instead
+        # of proper locations.
+
         if isinstance(addr, str):
-            getattr(self, addr)()
+            self.native_functions[addr](self)
             return next
         else:
             self.push_pc(self.pc + 1)
@@ -319,10 +326,7 @@
     def MakeObject(self):
         size = self.operand
         context, ref = self.value
-        classcode, attrcode, codeaddr, codedetails, instance = self.load(ref)
-        addr = self.new(size)
-        # Set the header to resemble the class.
-        self.save(addr, (classcode, attrcode, None, None, 1)) # NOTE: __call__ method not yet provided.
+        addr = self._MakeObject(size, ref)
         # Introduce null context for new object.
         self.value = None, addr
 
@@ -438,7 +442,7 @@
 
         # Check the details of the proposed context and the target's context.
 
-        self._CheckInstance(ref, target_context)
+        self.status = self._CheckInstance(ref, target_context)
 
     def JumpWithFrame(self):
         codeaddr, codedetails = self.callable
@@ -498,7 +502,7 @@
         self.handler_stack.pop()
 
     def CheckException(self):
-        self._CheckInstance(self.exception, self.value[1])
+        self.status = self.exception is not None and self._CheckInstance(self.exception, self.value[1])
 
     def TestIdentity(self):
         self.status = self.value[1] == self.source[1]
@@ -522,9 +526,55 @@
 
         element = self.objlist[target_classcode + attrcode]
         attr_index, class_attr, replace_context, offset = element
-        if attr_index == attrcode:
-            self.status = 1
-        else:
-            self.status = 0
+        return attr_index == attrcode
+
+    def _MakeObject(self, size, ref):
+        classcode, attrcode, codeaddr, codedetails, instance = self.load(ref)
+        addr = self.new(size)
+        # Set the header to resemble the class.
+        self.save(addr, (classcode, attrcode, None, None, 1)) # NOTE: __call__ method not yet provided.
+        return addr
+
+    # Native function implementations.
+
+    def builtins_object_init(self):
+        pass
+
+    def builtins_int_init(self):
+        pass
+
+    def builtins_int_add(self):
+        frame = self.local_sp_stack[-1]
+
+        # Get operands addresses.
+
+        left_context, left = self.frame_stack[frame]
+        right_context, right = self.frame_stack[frame + 1]
+
+        # Test operand suitability.
+
+        if not self._CheckInstance(left, self.int_class) and self._CheckInstance(right, self.int_class):
+            self.exception = self.type_error
+            return self.RaiseException()
+
+        # NOTE: Assume single location for data.
+
+        left_data = left + 1
+        right_data = right + 1
+
+        # Make a new object.
+
+        addr = self._MakeObject(2, self.int_class)
+        self.save(addr + 1, self.load(left_data) + self.load(right_data))
+
+        # Return the new object (with a null context).
+
+        self.result = None, addr
+
+    native_functions = {
+        "__builtins__.object.__init__" : builtins_object_init,
+        "__builtins__.int.__init__" : builtins_int_init,
+        "__builtins__.int.__add__" : builtins_int_add,
+        }
 
 # vim: tabstop=4 expandtab shiftwidth=4
diff -r 831ab0ba3de6 -r 168c6f68045d test.py
--- a/test.py	Sun Jan 25 02:56:16 2009 +0100
+++ b/test.py	Mon Jan 26 01:25:30 2009 +0100
@@ -37,12 +37,10 @@
     pt = program.get_parameter_table()
     objlist = ot.as_list()
     paramlist = pt.as_list()
-    attr_error = objlist.access("__builtins__", "AttributeError").value.location
-    type_error = objlist.access("__builtins__", "TypeError").value.location
     print "Getting raw image..."
     rc = program.get_raw_image()
     print "Initialising the machine..."
-    rm = rsvp.RSVPMachine(rc, objlist.as_raw(), paramlist.as_raw(), attr_error, type_error, debug=debug)
+    rm = rsvp.RSVPMachine(rc, objlist, paramlist, debug=debug)
     rm.pc = program.code_location
     return rm