<!-- manual page source format generated by PolyglotMan v3.0.9, -->
<!-- available via anonymous ftp from ftp.cs.berkeley.edu:/ucb/people/phelps/tcltk/rman.tar.Z -->
<HTML>
<HEAD>
<TITLE>Blt_TreeCreate(3) manual page</TITLE>
</HEAD>
<BODY bgcolor=white>
<A HREF="#toc">Table of Contents</A><P>
<H2><A NAME="sect0" HREF="#toc0">Name</A></H2>
Blt_TreeCreate - Create tree data
object.
<H2><A NAME="sect1" HREF="#toc1">Synopsis</A></H2>
<BR>
<PRE>#include <bltTree.h>
int
Blt_TreeCreate(interp, name, tokenPtr)
</PRE>
<H2><A NAME="sect2" HREF="#toc2">Arguments</A></H2>
<P>
Tcl_Interp <I>*interp</I><tt> </tt> <tt> </tt> (in)<BR>
<tt> </tt> <tt> </tt> Interpreter to report results back to. <P>
const char <I>*name</I><tt> </tt> <tt> </tt> (in)<BR>
<tt> </tt> <tt> </tt> Name of the new tree. Can be qualified by a namespace. <P>
Blt_Tree <I>*tokenPtr</I><tt> </tt> <tt> </tt> (out)<BR>
<tt> </tt> <tt> </tt> If not NULL, points to location to store the client tree token.
<H2><A NAME="sect3" HREF="#toc3">Description</A></H2>
<P>
This
procedure creates a C-based tree data object and optionally returns a token
to it. The arguments are as follows:
<DL>
<DT><I>interp</I> </DT>
<DD>Interpreter to report results
back to. If an error occurs, then interp->result will contain an error message.
</DD>
<DT><I>name</I> </DT>
<DD>Name of the new tree object. You can think of <I>name</I> as the memory address
of the object. It's a unique name that identifies the tree object. No tree
object <I>name</I> can already exist. <I>Name</I> can be qualified by a namespace such
as fred::myTree. If no namespace qualifier is used, the tree will be
created in the current namespace, not the global namespace. If a qualifier
is present, the namespace must already exist. </DD>
<DT><I>tokenPtr</I> </DT>
<DD>Holds the returned
token. <I>TokenPtr</I> points to a location where it is stored. Tree tokens are
used to work with the tree object. If NULL, no token is allocated. You
can later use <B>Tcl_TreeGetToken</B> to obtain a token. </DD>
</DL>
<P>
The new tree data object
created will initially contain only a root node. You can add new nodes
with <B>Blt_TreeCreateNode</B>. <P>
Optionally a token for the tree data object is
returned. Tree data objects can be shared. For example, the <B>tree</B> and <B>hiertable</B>
commands may be accessing the same tree data object. Each client grabs a
token that is associated with the tree. When all tokens are released (see
<B>Blt_TreeReleaseToken</B>) the tree data object is automatically destroyed. <P>
<H2><A NAME="sect4" HREF="#toc4">Returns</A></H2>
A
standard Tcl result is returned. If TCL_ERROR is returned, then <I>interp->result</I>
will contain an error message. The following errors may occur:
<UL>
<LI>There already
exists a tree by the same name as <I>name</I>. You can use <B>Tcl_TreeExists</B> to determine
if a tree exists beforehand. </LI><LI>The tree name is prefixed by a namespace that
doesn't exist. If you qualified the tree name with a namespace, the namespace
must exist. Unlike Tcl procs and variables, the namespace is not automatically
created for you. </LI><LI>Memory can't be allocated for the tree or token. </LI>
</UL>
<H2><A NAME="sect5" HREF="#toc5">Example</A></H2>
The
following example creates a new <BR>
<CODE>Blt_Tree token;<BR>
<P>
if (Blt_TreeCreate(interp, "myTree", &token) != TCL_OK) {<BR>
return TCL_ERROR;<BR>
}<BR>
printf("tree is %s\n", Blt_TreeName(token));<BR>
<H2><A NAME="sect6" HREF="#toc6"></CODE>Keywords</A></H2>
Tcl_TreeGetToken, Tcl_TreeExists, Tcl_TreeReleaseToken <P>
<HR><P>
<A NAME="toc"><B>Table of Contents</B></A><P>
<UL>
<LI><A NAME="toc0" HREF="#sect0">Name</A></LI>
<LI><A NAME="toc1" HREF="#sect1">Synopsis</A></LI>
<LI><A NAME="toc2" HREF="#sect2">Arguments</A></LI>
<LI><A NAME="toc3" HREF="#sect3">Description</A></LI>
<LI><A NAME="toc4" HREF="#sect4">Returns</A></LI>
<LI><A NAME="toc5" HREF="#sect5">Example</A></LI>
<LI><A NAME="toc6" HREF="#sect6">Keywords</A></LI>
</UL>
</BODY></HTML>
