diff options
Diffstat (limited to 'Doc/api/concrete.tex')
-rw-r--r-- | Doc/api/concrete.tex | 50 |
1 files changed, 50 insertions, 0 deletions
diff --git a/Doc/api/concrete.tex b/Doc/api/concrete.tex index 64653a9..5afe6b8 100644 --- a/Doc/api/concrete.tex +++ b/Doc/api/concrete.tex @@ -2340,3 +2340,53 @@ information on using these objects. Returns the description \ctype{void *} that the \ctype{PyCObject} \var{self} was created with. \end{cfuncdesc} + + +\subsection{Cell Objects \label{cell-objects}} + +``Cell'' objects are used to implement variables referenced by +multiple scopes. For each such variable, a cell object is created to +store the value; the local variables of each stack frame that +references the value contains a reference to the cells from outer +scopes which also use that variable. When the value is accessed, the +value contained in the cell is used instead of the cell object +itself. This de-referencing of the cell object requires support from +the generated byte-code; these are not automatically de-referenced +when accessed. Cell objects are not likely to be useful elsewhere. + +\begin{cvardesc}{PyTypeObject}{PyCell_Type} + The type object corresponding to cell objects +\end{cvardesc} + +\begin{cfuncdesc}{int}{PyCell_Check}{ob} + Return true if \var{ob} is a cell object; \var{ob} must not be + \NULL. +\end{cfuncdesc} + +\begin{cfuncdesc}{PyObject*}{PyCell_New}{PyObject *ob} + Create and return a new cell object containing the value \var{ob}. + The parameter may be \NULL. +\end{cfuncdesc} + +\begin{cfuncdesc}{PyObject*}{PyCell_Get}{PyObject *cell} + Return the contents of the cell \var{cell}. +\end{cfuncdesc} + +\begin{cfuncdesc}{PyObject*}{PyCell_GET}{PyObject *cell} + Return the contents of the cell \var{cell}, but without checking + that \var{cell} is non-\NULL{} and a call object. +\end{cfuncdesc} + +\begin{cfuncdesc}{int}{PyCell_Set}{PyObject *cell, PyObject *value} + Set the contents of the cell object \var{cell} to \var{value}. This + releases the reference to any current content of the cell. + \var{value} may be \NULL. \var{cell} must be non-\NULL; if it is + not a cell object, \code{-1} will be returned. On success, \code{0} + will be returned. +\end{cfuncdesc} + +\begin{cfuncdesc}{void}{PyCell_SET}{PyObject *cell, PyObject *value} + Sets the value of the cell object \var{cell} to \var{value}. No + reference counts are adjusted, and no checks are made for safety; + \var{cell} must be non-\NULL{} and must be a cell object. +\end{cfuncdesc} |