'\"
'\" Copyright (c) 1993-1997 Bell Labs Innovations for Lucent Technologies
'\" Copyright (c) 1997 Sun Microsystems, Inc.
'\" Copyright (c) 2000 Scriptics Corporation.
'\" Copyright (c) 2004-2005 Donal K. Fellows.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
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'\" RCS: @(#) $Id: namespace.n,v 1.10.2.16 2008/09/29 13:52:40 dgp Exp $
'\" 
.so man.macros
.TH namespace n 8.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
namespace \- create and manipulate contexts for commands and variables

For the \fIstring\fR \fB::foo::bar::x\fR,
this command returns \fBx\fR,
and for \fB::\fR it returns an empty string.
This command is the complement of the \fBnamespace qualifiers\fR command.
It does not check whether the namespace names are, in fact,
the names of currently defined namespaces.
.TP
\fBnamespace upvar\fR \fInamespace\fR ?\fIotherVar myVar \fR...
.
This command arranges for zero or more local variables in the current
procedure to refer to variables in \fInamespace\fR. The namespace name is
resolved as described in section \fBNAME RESOLUTION\fR.
The command
\fBnamespace upvar $ns a b\fR has the same behaviour as
\fBupvar 0 ${ns}::a b\fR, with the sole exception of the resolution rules
used for qualified namespace or variable names.
\fBnamespace upvar\fR returns an empty string.

in place of the ensemble command and subcommand words (in a manner
similar to an alias created with \fBinterp alias\fR; the words are not
reparsed after substitution).  When this option is empty, the mapping
will be from the local name of the subcommand to its fully-qualified
name.  Note that when this option is non-empty and the
\fB\-subcommands\fR option is empty, the ensemble subcommand names
will be exactly those words that have mappings in the dictionary.
.TP
\fB\-parameters\fR
.VS 8.6
This option gives a list of named arguments (the names being used during
generation of error messages) that are passed by the caller of the ensemble
between the name of the ensemble and the subcommand argument. By default, it
is the empty list.
.VE 8.6
.TP
\fB\-prefixes\fR
.
This option (which is enabled by default) controls whether the
ensemble command recognizes unambiguous prefixes of its subcommands.
When turned off, the ensemble command requires exact matching of
subcommand names.

puts "grill came from [\fBnamespace origin\fR grill]"
.CE
.PP
Remove all imported commands from the current namespace:
.CS
namespace forget {*}[namespace import]
.CE
.PP
.VS 8.6
Create an ensemble for simple working with numbers, using the
\fB\-parameters\fR option to allow the operator to be put between the first
and second arguments.
.CS
\fBnamespace eval\fR do {
   \fBnamespace export\fR *
   \fBnamespace ensemble\fR create -parameters x
   proc plus  {x y} {expr { $x + $y }}
   proc minus {x y} {expr { $x - $y }}
}

# In use, the ensemble works like this:
puts [do 1 plus [do 9 minus 7]]
.CE
.VE 8.6
.SH "SEE ALSO"
interp(n), upvar(n), variable(n)
.SH KEYWORDS
command, ensemble, exported, internal, variable
'\" Local Variables:
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'\" End: