Author: Armin Rigo <ar...@tunes.org> Branch: Changeset: r640:211cbd67684d Date: 2012-07-13 22:57 +0200 http://bitbucket.org/cffi/cffi/changeset/211cbd67684d/
Log: Document the conversions. diff --git a/TODO b/TODO --- a/TODO +++ b/TODO @@ -3,6 +3,8 @@ Next steps ---------- +ffi.new(): require a pointer-or-array type? + verify() handles "typedef ... some_integer_type", but this creates an opaque type that works like a struct (so we can't get the value out of it). diff --git a/doc/source/index.rst b/doc/source/index.rst --- a/doc/source/index.rst +++ b/doc/source/index.rst @@ -737,6 +737,89 @@ of the C type "pointer to the same type than x". +Reference: conversions +---------------------- + +This section documents all the conversions that are allowed when +*writing into* a C data structure (or passing arguments to a function +call), and *reading from* a C data structure (or getting the result of a +function call). The last column gives the type-specific operations +allowed. + ++---------------+------------------------+------------------+----------------+ +| C type | writing into | reading from |other operations| ++===============+========================+==================+================+ +| integers | an integer or anything | a Python int or | int() | +| | on which int() works | long, depending | | +| | (but not a float!). | on the type | | +| | Must be within range. | | | ++---------------+------------------------+------------------+----------------+ +| ``char`` | a string of length 1 | a string of | str(), int() | +| | or another <cdata char>| length 1 | | ++---------------+------------------------+------------------+----------------+ +| ``wchar_t`` | a unicode of length 1 | a unicode of | unicode(), | +| | (or maybe 2 if | length 1 | int() | +| | surrogates) or | (or maybe 2 if | | +| | another <cdata wchar_t>| surrogates) | | ++---------------+------------------------+------------------+----------------+ +| ``float``, | a float or anything on | a Python float | float(), int() | +| ``double`` | which float() works | | | ++---------------+------------------------+------------------+----------------+ +| pointers | another <cdata> with | a <cdata> | ``+``, ``-`` | +| | a compatible type (i.e.| | | +| | same type or ``char*`` | | | +| | or ``void*``, or as an | | | +| | array instead) | | | ++---------------+------------------------+ +----------------+ +| ``void *`` | another <cdata> with | | | +| | any pointer or array | | | +| | type | | | ++---------------+------------------------+ +----------------+ +| ``char *`` | another <cdata> with | | ``+``, ``-``, | +| | any pointer or array | | str() | +| | type, or | | | +| | a Python string when | | | +| | passed as func argument| | | ++---------------+------------------------+ +----------------+ +| ``wchar_t *`` | same as pointers | | ``+``, ``-``, | +| | (passing a unicode as | | unicode() | +| | func argument is not | | | +| | implemented) | | | ++---------------+------------------------+ +----------------+ +| pointers to | same as pointers | | ``+``, ``-``, | +| structure or | | | and read/write | +| union | | | struct fields | ++---------------+ | +----------------+ +| function | | | call | +| pointers | | | | ++---------------+------------------------+------------------+----------------+ +| arrays | a list or tuple of | a <cdata> | len(), iter(), | +| | items | | ``+``, ``-`` | ++---------------+------------------------+ +----------------+ +| ``char[]`` | same as arrays, or a | | len(), iter(), | +| | Python string | | ``+``, ``-``, | +| | | | str() | ++---------------+------------------------+ +----------------+ +| ``wchar_t[]`` | same as arrays, or a | | len(), iter(), | +| | Python unicode | | ``+``, ``-``, | +| | | | unicode() | ++---------------+------------------------+------------------+----------------+ +| structure | a list or tuple or | a <cdata> | read/write | +| | dict of the field | | fields | +| | values, or a same-type | | | +| | <cdata> | | | ++---------------+------------------------+ +----------------+ +| union | same as struct, but | | read/write | +| | with at most one field | | fields | ++---------------+------------------------+------------------+----------------+ +| enum | an integer, or the enum| the enum value | int(), str() | +| | value as a string or | as a string, or | | +| | as ``"#NUMBER"`` | ``"#NUMBER"`` | | +| | | if out of range | | ++---------------+------------------------+------------------+----------------+ + + + Comments and bugs ================= _______________________________________________ pypy-commit mailing list pypy-commit@python.org http://mail.python.org/mailman/listinfo/pypy-commit
