Import Tcl-core 8.6.6 (as of svn r86089)

doc/copy.n

@@ -0,0 +1,66 @@
+'\"
+'\" Copyright (c) 2007 Donal K. Fellows
+'\"
+'\" See the file "license.terms" for information on usage and redistribution
+'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
+'\"
+.TH copy n 0.1 TclOO "TclOO Commands"
+.so man.macros
+.BS
+'\" Note:  do not modify the .SH NAME line immediately below!
+.SH NAME
+oo::copy \- create copies of objects and classes
+.SH SYNOPSIS
+.nf
+package require TclOO
+
+\fBoo::copy\fI sourceObject \fR?\fItargetObject\fR?
+.fi
+.BE
+.SH DESCRIPTION
+.PP
+The \fBoo::copy\fR command creates a copy of an object or class. It takes the
+name of the object or class to be copied, \fIsourceObject\fR, and optionally
+the name of the object or class to create, \fItargetObject\fR, which will be
+resolved relative to the current namespace if not an absolute qualified name.
+If \fItargetObject\fR is omitted, a new name is chosen. The copied object will
+be of the same class as the source object, and will have all its per-object
+methods copied. If it is a class, it will also have all the class methods in
+the class copied, but it will not have any of its instances copied.
+.PP
+.VS
+After the \fItargetObject\fR has been created and all definitions of its
+configuration (e.g., methods, filters, mixins) copied, the \fB<cloned>\fR
+method of \fItargetObject\fR will be invoked, to allow for customization of
+the created object such as installing related variable traces. The only
+argument given will be \fIsourceObject\fR. The default implementation of this
+method (in \fBoo::object\fR) just copies the procedures and variables in the
+namespace of \fIsourceObject\fR to the namespace of \fItargetObject\fR. If
+this method call does not return a result that is successful (i.e., an error
+or other kind of exception) then the \fItargetObject\fR will be deleted and an
+error returned.
+.VE
+.PP
+The result of the \fBoo::copy\fR command will be the fully-qualified name of
+the new object or class.
+.SH EXAMPLES
+.PP
+This example creates an object, copies it, modifies the source object, and
+then demonstrates that the copied object is indeed a copy.
+.PP
+.CS
+oo::object create src
+oo::objdefine src method msg {} {puts foo}
+\fBoo::copy\fR src dst
+oo::objdefine src method msg {} {puts bar}
+src msg              \fI\(-> prints "bar"\fR
+dst msg              \fI\(-> prints "foo"\fR
+.CE
+.SH "SEE ALSO"
+oo::class(n), oo::define(n), oo::object(n)
+.SH KEYWORDS
+clone, copy, duplication, object
+.\" Local variables:
+.\" mode: nroff
+.\" fill-column: 78
+.\" End: