Author: Armin Rigo <[email protected]>
Branch: extradoc
Changeset: r5600:6c7e299c3d71
Date: 2016-02-02 11:24 +0100
http://bitbucket.org/pypy/extradoc/changeset/6c7e299c3d71/
Log: expand a bit the cffi part
diff --git a/talk/swisspython2016/slides.rst b/talk/swisspython2016/slides.rst
--- a/talk/swisspython2016/slides.rst
+++ b/talk/swisspython2016/slides.rst
@@ -135,15 +135,83 @@
* ``lib`` gives access to all functions from the cdef
-* ``ffi`` gives access to a few general helpers, e.g.
+* ``ffi`` gives access to a few general helpers
- - ``ffi.cast("float", 42)``
- - ``p = ffi.new("struct passwd *")``
+ffi.cdef()
+==========
- - ``p = ffi.new("char[10]"); p[0] = 'X'; s = lib.getpwnam(p)``
+::
- - ``p = ffi.new_handle(random_obj); ...; random_obj = ffi.from_handle(p)``
+ ffi.cdef("""
+ int foo1(int a, int b);
+
+ typedef ... Window;
+ Window *make_window(int, int, int);
+ void hide_window(Window *);
+ """)
+
+
+ffi.new()
+=========
+
+::
+
+ >>> p = ffi.new("char[]", "Some string")
+ >>> p
+ <cdata 'char[]' owning 12 bytes>
+ >>> p[1]
+ 'o'
+ >>> q = lib.getpwnam(p)
+ >>> q
+ <cdata 'struct passwd *' 0x12345678>
+ >>> q.pw_uid
+ 500
+
+ffi.cast()
+==========
+
+::
+
+ >>> p = lib.getpwnam("root")
+ >>> p
+ <cdata 'struct passwd *' 0x12345678>
+ >>> ffi.cast("void *", p)
+ <cdata 'void *' 0x12345678>
+ >>> ffi.cast("long", p)
+ 305419896
+ >>> hex(_)
+ 0x12345678
+
+ffi.new_handle()
+================
+
+::
+
+ >>> h1 = ffi.new_handle(some_object)
+ >>> h1
+ <cdata 'void *' handle to <X object at 0x123456>>
+ >>> lib.same_away(h1)
+
+ >>> h2 = lib.fish_again()
+ >>> h2
+ <cdata 'void *' 0x87654321>
+ >>> ffi.from_handle(h2)
+ <X object at 0x123456>
+
+ffi.string()
+============
+
+::
+
+ >>> p
+ <cdata 'struct passwd *' 0x12345678>
+ >>> p.pw_uid
+ 500
+ >>> p.pw_name
+ <cdata 'char *' 0x5234abcd>
+ >>> ffi.string(p.pw_name)
+ "username"
CFFI
@@ -151,7 +219,7 @@
* supports more or less the whole C
-* there is more than my short explanation suggests
+* there is more than my short explanations suggests
* read the docs: http://cffi.readthedocs.org/
_______________________________________________
pypy-commit mailing list
[email protected]
https://mail.python.org/mailman/listinfo/pypy-commit
