# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1203375922 -3600
# Node ID 27ab716dcedb9a6e8636544bb1c407b4a67b73d8
# Parent  136f6bf70d3fc9122ded82a369a565973e65c4e4
Added notes, support, instructions related to proper method invocations.

diff -r 136f6bf70d3f -r 27ab716dcedb README.txt
--- a/README.txt	Mon Feb 18 01:22:25 2008 +0100
+++ b/README.txt	Tue Feb 19 00:05:22 2008 +0100
@@ -27,6 +27,21 @@
 Data Structures
 ===============
 
+The fundamental "value type" is a pair of references: one pointing to the
+referenced object represented by the interchangeable value; one referring to
+the context of the referenced object, typically the object through which the
+referenced object was acquired as an attribute.A
+
+Value Layout
+------------
+
+    0           1
+    object      context
+    reference   reference
+
+Objects
+-------
+
 Since classes, functions and instances are all "objects", each must support
 certain features and operations in the same way.
 
@@ -190,6 +205,27 @@
 Keyword arguments are set using an attribute-like mechanism, though, where the
 position of each argument discovered using the parameter table.
 
+Method invocations incorporate an implicit first argument which is obtained
+from the context of the method:
+
+    method(a, b, d=1, e=2, c=3) -> method(self, a, b, c, d, e)
+
+    Value Stack
+    -----------
+
+    ...
+    method
+    context of method
+    a
+    b
+    3
+    1
+    2
+
+Although it could be possible to permit any object to be provided as the first
+argument, in order to optimise instance attribute access in methods, we should
+seek to restrict the object type.
+
 Tuples, Frames and Allocation
 -----------------------------
 
diff -r 136f6bf70d3f -r 27ab716dcedb micropython/ast.py
--- a/micropython/ast.py	Mon Feb 18 01:22:25 2008 +0100
+++ b/micropython/ast.py	Tue Feb 19 00:05:22 2008 +0100
@@ -278,18 +278,18 @@
         the correct location, then invoke the function.
         """
 
-        # Record the location of the invocation.
+        # Mark the frame, evaluate the target, generate the call.
+
+        self._startCallFunc()
+        self.dispatch(node.node)
+        self._generateCallFunc(node.args, node)
+
+    def _startCallFunc(self):
+
+        "Record the location of the invocation."
 
         self.new_op(MakeFrame()) # records the start of the frame
 
-        # Evaluate the target.
-
-        self.dispatch(node.node)
-
-        # Generate the call.
-
-        self._generateCallFunc(node.args, node)
-
     def _generateCallFunc(self, args, node):
 
         # NOTE: Only simple cases are used for optimisations.
@@ -297,8 +297,24 @@
         last = self.last_op()
         if isinstance(last, (LoadName, LoadAttr)) and last.attr.assignments == 1:
             target = last.attr.value
+            context = last.attr.parent
         else:
             target = None
+            context = None
+
+        # Where a target is known and has a known context, avoid generating any
+        # first argument.
+
+        if context is not None:
+            pass # NOTE: Class methods should be supported.
+        else:
+            continue_label = self.new_label()
+            self.new_op(LoadContext())
+            self.new_op(CheckContext())
+            self.new_op(JumpIfTrue(continue_label))
+            self.new_op(LoadConst("TypeError")) # NOTE: Do this properly!
+            self.new_op(RaiseException())
+            self.set_label(continue_label)
 
         # Evaluate the arguments.
 
@@ -418,6 +434,7 @@
 
         # Get the "list" to be iterated over, obtain its iterator.
 
+        self._startCallFunc()
         self.dispatch(node.list)
         self._generateAttr("__iter__", (LoadAttr, LoadAttrIndex))
         self._generateCallFunc([], node)
@@ -429,6 +446,7 @@
 
         # Use the iterator to get the next value.
 
+        self._startCallFunc()
         self.new_op(Duplicate())
         self._generateAttr("next", (LoadAttr, LoadAttrIndex))
         self._generateCallFunc([], node)
diff -r 136f6bf70d3f -r 27ab716dcedb micropython/rsvp.py
--- a/micropython/rsvp.py	Mon Feb 18 01:22:25 2008 +0100
+++ b/micropython/rsvp.py	Tue Feb 19 00:05:22 2008 +0100
@@ -62,11 +62,14 @@
 
 # Invocation-related instructions.
 
-class Jump(Instruction): pass
-class JumpIfFalse(Instruction): pass
-class JumpIfTrue(Instruction): pass
-class LoadCallable(Instruction): pass
-class Return(Instruction): pass
-class CheckException(Instruction): pass
+class Jump(Instruction):            "Jump unconditionally."
+class JumpIfFalse(Instruction):     "Jump if the last evaluation gave a false result."
+class JumpIfTrue(Instruction):      "Jump if the last evaluation gave a true result."
+class LoadCallable(Instruction):    "Load the target of an invocation."
+class LoadContext(Instruction):     "Load the context of an invocation."
+class CheckContext(Instruction):    "Check the context of an invocation against the target."
+class RaiseException(Instruction):  "Raise an exception."
+class Return(Instruction):          "Return a value from a subprogram."
+class CheckException(Instruction):  "Check the raised exception against another."
 
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