# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1385683460 -3600
# Node ID 94cb3ad3225a79736b9b41a44d83187173cb1b58
# Parent  fa655857f2bae346e5b09e12e5331c80292c368a
Added some documentation about defaults and dynamic functions.

diff -r fa655857f2ba -r 94cb3ad3225a docs/syspython.txt
--- a/docs/syspython.txt	Fri Nov 29 01:03:47 2013 +0100
+++ b/docs/syspython.txt	Fri Nov 29 01:04:20 2013 +0100
@@ -124,6 +124,63 @@
         if something:
             storeattr(module.C, method, something)
 
+Local class or function definitions are also handled in a similar fashion to
+those at the module level, although there is no explicit __main__ function
+within each function.
+
+For example:
+
+    def outer(x):
+        if something:
+            def inner(...):
+                ...
+        else:
+            def inner(...):
+                ...
+        return inner
+
+This is represented as follows:
+
+    def outer(x):
+        def inner(...):
+            ...
+        def inner(...):
+            ...
+
+        if something:
+            storelocal(inner, static(outer.inner))
+        else:
+            storelocal(inner, static("outer.inner#2"))
+        return inner
+
+Where functions are dynamic - that is they have additional state associated
+with them, such as defaults (or potentially closures if supported) that are
+not static (such as constant values) - suitable objects must be created using
+references to such functions.
+
+For example:
+
+    def outer(x):
+        def inner(y, z=x):
+            ...
+        return inner
+
+This is represented as follows:
+
+    def outer(x):
+        def inner(__context__, y, z=x):
+            localnames(__context__, y, z)
+            ...
+        storelocal(inner, makedynamic(static(outer.inner), x))
+        return inner
+
+The special makedynamic invocation creates an object referring to the function
+and incorporating any specified defaults as attributes of that object. The
+function itself uses a special __context__ parameter that acts somewhat like
+the self parameter in methods: when invoked, the __context__ provides access
+to any default information that needs to be transferred to the local
+namespace.
+
 Imports
 -------