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Diffstat (limited to 'Doc/ext/extending.tex')
| -rw-r--r-- | Doc/ext/extending.tex | 34 |
1 files changed, 17 insertions, 17 deletions
diff --git a/Doc/ext/extending.tex b/Doc/ext/extending.tex index 49a561c..22623e9 100644 --- a/Doc/ext/extending.tex +++ b/Doc/ext/extending.tex @@ -1,4 +1,4 @@ -\chapter{Extending Python with C or \Cpp{} \label{intro}} +\chapter{Extending Python with C or \Cpp \label{intro}} It is quite easy to add new built-in modules to Python, if you know @@ -499,14 +499,14 @@ This function must be registered with the interpreter using the \constant{METH_VARARGS} flag; this is described in section \ref{methodTable}, ``The Module's Method Table and Initialization Function.'' The \cfunction{PyArg_ParseTuple()} function and its -arguments are documented in section \ref{parseTuple}, ``Extracting +arguments are documented in section~\ref{parseTuple}, ``Extracting Parameters in Extension Functions.'' The macros \cfunction{Py_XINCREF()} and \cfunction{Py_XDECREF()} increment/decrement the reference count of an object and are safe in the presence of \NULL{} pointers (but note that \var{temp} will not be -\NULL{} in this context). More info on them in section -\ref{refcounts}, ``Reference Counts.'' +\NULL{} in this context). More info on them in +section~\ref{refcounts}, ``Reference Counts.'' Later, when it is time to call the function, you call the C function \cfunction{PyEval_CallObject()}. This function has two arguments, both @@ -544,7 +544,7 @@ global variable, you should somehow \cfunction{Py_DECREF()} the result, even (especially!) if you are not interested in its value. Before you do this, however, it is important to check that the return -value isn't \NULL{}. If it is, the Python function terminated by +value isn't \NULL. If it is, the Python function terminated by raising an exception. If the C code that called \cfunction{PyEval_CallObject()} is called from Python, it should now return an error indication to its Python caller, so the interpreter @@ -652,7 +652,7 @@ representation. \item[\samp{z} (string or \code{None}) {[char *]}] Like \samp{s}, but the Python object may also be \code{None}, in which -case the C pointer is set to \NULL{}. +case the C pointer is set to \NULL. \item[\samp{z\#} (string or \code{None} or any read buffer compatible object) {[char *, int]}] @@ -680,7 +680,7 @@ first one a pointer to an encoding name string (\var{encoding}), and the second a pointer to a pointer to a character buffer (\var{**buffer}, the buffer used for storing the encoded data). -The encoding name must map to a registered codec. If set to \NULL{}, +The encoding name must map to a registered codec. If set to \NULL, the default encoding is used. \cfunction{PyArg_ParseTuple()} will allocate a buffer of the needed @@ -705,7 +705,7 @@ pointer to a character buffer (\var{**buffer}, the buffer used for storing the encoded data) and the third one a pointer to an integer (\var{*buffer_length}, the buffer length). -The encoding name must map to a registered codec. If set to \NULL{}, +The encoding name must map to a registered codec. If set to \NULL, the default encoding is used. There are two modes of operation: @@ -766,7 +766,7 @@ Convert a Python complex number to a C \ctype{Py_complex} structure. Store a Python object (without any conversion) in a C object pointer. The C program thus receives the actual object that was passed. The object's reference count is not increased. The pointer stored is not -\NULL{}. +\NULL. \item[\samp{O!} (object) {[\var{typeobject}, PyObject *]}] Store a Python object in a C object pointer. This is similar to @@ -945,7 +945,7 @@ int PyArg_ParseTupleAndKeywords(PyObject *arg, PyObject *kwdict, The \var{arg} and \var{format} parameters are identical to those of the \cfunction{PyArg_ParseTuple()} function. The \var{kwdict} parameter is the dictionary of keywords received as the third parameter from the -Python runtime. The \var{kwlist} parameter is a \NULL{}-terminated +Python runtime. The \var{kwlist} parameter is a \NULL-terminated list of strings which identify the parameters; the names are matched with the type information from \var{format} from left to right. On success, \cfunction{PyArg_ParseTupleAndKeywords()} returns true, @@ -1055,11 +1055,11 @@ used to make long format strings a tad more readable. \item[\samp{s} (string) {[char *]}] Convert a null-terminated C string to a Python object. If the C -string pointer is \NULL{}, \code{None} is used. +string pointer is \NULL, \code{None} is used. \item[\samp{s\#} (string) {[char *, int]}] Convert a C string and its length to a Python object. If the C string -pointer is \NULL{}, the length is ignored and \code{None} is +pointer is \NULL, the length is ignored and \code{None} is returned. \item[\samp{z} (string or \code{None}) {[char *]}] @@ -1171,10 +1171,10 @@ Examples (to the left the call, to the right the resulting Python value): \section{Reference Counts \label{refcounts}} -In languages like C or \Cpp{}, the programmer is responsible for +In languages like C or \Cpp, the programmer is responsible for dynamic allocation and deallocation of memory on the heap. In C, this is done using the functions \cfunction{malloc()} and -\cfunction{free()}. In \Cpp{}, the operators \keyword{new} and +\cfunction{free()}. In \Cpp, the operators \keyword{new} and \keyword{delete} are used with essentially the same meaning; they are actually implemented using \cfunction{malloc()} and \cfunction{free()}, so we'll restrict the following discussion to the @@ -1423,7 +1423,7 @@ cause later core dumps) if you do so. Functions that return object references generally return \NULL{} only to indicate that an exception occurred. The reason for not testing for \NULL{} arguments is that functions often pass the objects they receive on to -other function --- if each function were to test for \NULL{}, +other function --- if each function were to test for \NULL, there would be a lot of redundant tests and the code would run more slowly. @@ -1458,10 +1458,10 @@ the Python user. % description. -\section{Writing Extensions in \Cpp{} +\section{Writing Extensions in \Cpp \label{cplusplus}} -It is possible to write extension modules in \Cpp{}. Some restrictions +It is possible to write extension modules in \Cpp. Some restrictions apply. If the main program (the Python interpreter) is compiled and linked by the C compiler, global or static objects with constructors cannot be used. This is not a problem if the main program is linked |