.. hoc:class:: Pointer
Syntax:
``Pointer(&x)``
``Pointer("variable")``
``Pointer(&x, "stmt that may contain $1")``
``Pointer("variable", "stmt that may contain $1 or variable name")``
Description:
Holds a reference to a variable. When memory for the variable is freed,
the Pointer will return an error if used.
See :hoc:meth:`Pointer.assign` for the meaning of the optional second arg.
.. hoc:method:: Pointer.val
Syntax:
``x = ptr.val``
``ptr.val = expr``
Description:
Returns the value of the variable pointed to by ptr or, if the left
hand side of an assignment, sets the value of the variable.
.. hoc:method:: Pointer.s
Syntax:
``str = ptr.s``
Description:
If the Pointer was constructed with the name of a variable, that name
can be retrieved as a strdef.
.. hoc:method:: Pointer.assign
Syntax:
``x = ptr.assign(val)``
Description:
Sets the value of the pointer variable to val. If prt was constructed
with a second arg then the execution depends on its form. If the
second arg string contains one or more $1 tokens, then the tokens
are replaced by :hoc:data:`hoc_ac_`, :hoc:data:`hoc_ac_` is set to the val and the resulting
statement is executed. Otherwise the second arg string is assumed to
be a variable name and a statement of the form
variablename = :hoc:data:`hoc_ac_` is executed.
Note that the compiling of these statements takes place just once when
the Pointer is constructed. Thus ptr.assign(val) is marginally
faster than execute("stmt with val").
(following not implemented) And if the stmt is a variablename
then the pointer is used and all interpreter overhead is avoided.
Also note that on construction, the second arg variable is executed with the
value of the first arg pointer. So
Returns val.