'\"
'\" XOTcl - Extended OTcl
'\" Copyright (C) 1999-2008 Uwe Zdun
'\" Copyright (C) 1999-2014 Gustaf Neumann
'\"
'\" 
.so man.macros
.TH xotclsh 1 "" XOTcl "XOTcl Applications"
.BS
.SH NAME
xotclsh \- Tcl Shell containing object-oriented scripting language XOTcl
.SH SYNOPSIS
\fBxotclsh\fR \fI?filename arg arg ...?\fR
.BE
.SH DESCRIPTION
.PP
\fBxotclsh\fR is a shell-like application that reads XOTcl commands
from its standard input or from a file and evaluates them.
Similarly as the relation between \fBtclsh\fR and \fBwish\fR, 
\fBxowish\fR 
provides all functionality of xotclsh and provides as well predefined
support for TK widgets.
.PP
XOTcl (XOTcl, pronounced exotickle) is an object-oriented scripting
language based on MIT's OTcl. It is intended as a value added
replacement of OTcl.
.PP
Scripting languages, such as Tcl, are designed for glueing components
together, provide features such as dynamic extensibility and dynamic
typing with automatic conversion, that make them well suited for rapid
application development.
.PP
The object system of XOTcl enables a user to to define objects, 
classes, and meta-classes. Classes are special objects with the
purpose of managing
other objects. ``Managing'' means that a class controls the creation
and destruction of its instances and that it contains a repository of
methods accessible for the instances. Every object may be enhanced
with object-specific methods. XOTcl supports single and multiple
inheritance. All object-class and class-class relationships in XOTcl
are introspectable and can be dynamically changed at arbitrary times.
Ambiguities in name resolution of methods are avoided
through method chaining through "next", which does not require
explicit method naming. 
.PP
XOTcl combines the ideas of scripting and object-orientation in a way
that preserves the benefits of both of them. It is equipped with
several new language constructs that help building and managing
complex systems. We added the following support:

.PP
\fIDynamic Object Aggregations\fR, 
to provide dynamic aggregations through nested namespaces (objects). 
.PP
\fINested Classes\fR, to reduce the interference
of independently developed program structures. 
.PP
\fIAssertions\fR, to reduce
the interface and the reliability problems caused by dynamic typing
and, therefore, to ease the combination of many components.
.PP
\fIMeta-data\fR, to enhance self-documentation of objects and 
classes.
.PP
\fIPer-object mixins\fR, as a means to give an object 
dynamically access to the methods of one or several supplemental classes.
.PP
\fIPer-class mixins\fR, as a means to give all instances of 
an class dynamically access to the methods of one or several 
supplemental classes.
.PP
\fIFilters\fR as a means of
abstractions over method invocations to implement large program
structures, like design patterns.

XOTcl provides a value-added replacement of Tcl
package loading providing integration with object-oriented constructs and
tracking/tracing of component loading.
.SH VARIABLES
.PP
\fBxotclsh\fR sets all variables that \fBtclsh\fR sets,
and additionally the following variables:

.TP 15
\fB::xotcl::version\fR XOTcl version number.
.TP 15
\fB::xotcl::confdir\fR Directory for XOTcl configuration.
.TP 15
\fB::xotcl::logdir\fR Directory where logfiles are placed.

.PP
.SH KEYWORDS
argument, interpreter, prompt, script file, shell