[Python-checkins] CVS: python/dist/src/Doc/lib libuserdict.tex,1.12,1.13

[Fred Drake]

Update of /projects/cvsroot/python/dist/src/Doc/lib
In directory seahag.cnri.reston.va.us:/home/fdrake/projects/python/Doc/lib

Modified Files:
	libuserdict.tex 
Log Message:

UserString class from Peter Funk <pf@artcom-gmbh.de>.


Index: libuserdict.tex
===================================================================
RCS file: /projects/cvsroot/python/dist/src/Doc/lib/libuserdict.tex,v
retrieving revision 1.12
retrieving revision 1.13
diff -C2 -r1.12 -r1.13
*** libuserdict.tex	1999/07/26 15:45:52	1.12
--- libuserdict.tex	2000/04/03 03:51:50	1.13
***************
*** 64,65 ****
--- 64,114 ----
  \class{UserList} class.
  \end{memberdesc}
+ 
+ 
+ \section{\module{UserString} ---
+          Class wrapper for string objects}
+ 
+ \declaremodule{standard}{UserString}
+ \modulesynopsis{Class wrapper for string objects.}
+ \moduleauthor{Peter Funk}{pf@artcom-gmbh.de}
+ \sectionauthor{Peter Funk}{pf@artcom-gmbh.de}
+ 
+ This module defines a class that acts as a wrapper around
+ string objects.  It is a useful base class for
+ your own string-like classes, which can inherit from
+ them and override existing methods or add new ones.  In this way one
+ can add new behaviours to strings.
+ 
+ The \module{UserString} module defines the \class{UserString} class:
+ 
+ \begin{classdesc}{UserString}{\optional{sequence}}
+ Return a class instance that simulates a string or an unicode string object.
+ The instance's content is kept in a regular string or unicode string
+ object, which is accessible via the
+ \member{data} attribute of \class{UserString} instances.  The instance's
+ contents are initially set to a copy of \var{sequence}.
+ \var{sequence} can be either a regular Python string or unicode string,
+ an instance of \class{UserString} (or a subclass) or an arbitrary sequence
+ which can be converted into a string.
+ supporting.
+ \end{classdesc}
+ 
+ In addition to supporting the methods and operations of string  or
+ unicode objects (see section \ref{typesseq}), \class{UserString} instances
+ provide the following attribute:
+ 
+ \begin{memberdesc}{data}
+ A real Python string or unicode object used to store the content of the
+ \class{UserString} class.
+ \end{memberdesc}
+ 
+ \begin{classdesc}{MutableString}{\optional{sequence}}
+ This class is derived from the \class{UserString} above and redefines
+ strings to be \emph{mutable}.  Mutable strings can't be used as
+ dictionary keys, because dictionaries require \emph{immutable} objects as
+ keys.  The main intention of this class is to serve as an educational
+ example for inheritance and necessity to remove (override) the
+ \function{__hash__} method in order to trap attempts to use a
+ mutable object as dictionary key, which would be otherwise very
+ errorprone and hard to track down.
+ \end{classdesc}