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<A HREF="#toc">Table of Contents</A><P>
<H2><A NAME="sect0" HREF="#toc0">Name</A></H2>
tree - Create and manage tree data objects.
<H2><A NAME="sect1" HREF="#toc1">Synopsis</A></H2>
<B>blt::tree
create </B>?<I>treeName</I>? <P>
<B>blt::tree destroy</B> <I>treeName</I>... <P>
<B>blt::tree names</B> ?<I>pattern</I>?
<H2><A NAME="sect2" HREF="#toc2">Description</A></H2>
The <B>tree</B> command creates tree data objects. A <I>tree object</I> is
general ordered tree of nodes. Each node has both a label and a key-value
list of data. Data can be heterogeneous, since nodes do not have to contain
the same data keys. It is associated with a Tcl command that you can use
to access and modify the its structure and data. Tree objects can also be
managed via a C API.
<H2><A NAME="sect3" HREF="#toc3">Introduction</A></H2>
<P>
<H2><A NAME="sect4" HREF="#toc4">Example</A></H2>
<P>
<H2><A NAME="sect5" HREF="#toc5">Syntax</A></H2>
<DL>
<DT><B>tree create</B> ?<I>treeName</I>?
</DT>
<DD>Creates a new tree object. The name of the new tree is returned. If no
<I>treeName</I> argument is present, then the name of the tree is automatically
generated in the form "<I>tree0</I>", "<I>tree1</I>", etc. If the substring "<I>#auto</I>" is
found in <I>treeName</I>, it is automatically substituted by a generated name.
For example, the name <I>.foo.#auto.bar</I> will be translated to <I>.foo.tree0.bar</I>. <P>
A
new Tcl command (by the same name as the tree) is also created. Another
Tcl command or tree object can not already exist as <I>treeName</I>. If the Tcl
command is deleted, the tree will also be freed. The new tree will contain
just the root node. Trees are by default, created in the current namespace,
not the global namespace, unless <I>treeName</I> contains a namespace qualifier,
such as "<I>fred::myTree</I>". </DD>
<DT><B>tree destroy</B> <I>treeName</I>... </DT>
<DD>Releases one of more trees.
The Tcl command associated with <I>treeName</I> is also removed. Trees are reference
counted. The internal tree data object isn't destroyed until no one else
is using the tree. </DD>
<DT><B>tree names </B>?<I>pattern</I>? </DT>
<DD>Returns the names of all tree objects.
if a <I>pattern</I> argument is given, then the only those trees whose name matches
pattern will be listed. </DD>
</DL>
<H2><A NAME="sect6" HREF="#toc6">Node IDs and Tags</A></H2>
Nodes in a tree object may be referred
in either of two ways: by id or by tag. Each node has a unique serial number
or id that is assigned to that node when it's created. The id of an node
never changes and id numbers are not re-used. <P>
A node may also have any number
of tags associated with it. A tag is just a string of characters, and it
may take any form except that of an integer. For example, "<I>x123</I>" is valid,
but "<I>123</I>" isn't. The same tag may be associated with many different nodes.
This is commonly done to group nodes in various interesting ways. <P>
There
are two built-in tags: The tag <B>all</B> is implicitly associated with every node
in the tree. It may be used to invoke operations on all the nodes in the
tree. The tag <B>root</B> is managed automatically by the tree object. It applies
to the node current set as root. <P>
When specifying nodes in tree object commands,
if the specifier is an integer then it is assumed to refer to the single
node with that id. If the specifier is not an integer, then it is assumed
to refer to all of the nodes in the tree that have a tag matching the specifier.
The symbol <I>node</I> is used below to indicate that an argument specifies either
an id that selects a single node or a tag that selects zero or more nodes.
Many tree commands only operate on a single node at a time; if <I>node</I> is
specified in a way that names multiple items, then an error "refers to
more than one node" is generated.
<H2><A NAME="sect7" HREF="#toc7">Node Modifiers</A></H2>
You can also specify node
in relation to another node by appending one or more modifiers to the node
id or tag. A modifier refers to a node in relation to the specified node.
For example, "<I>root->firstchild</I>" selects the first subtree of the root node.
<P>
The following modifiers are available: <blockquote>
<DL>
<DT><B>firstchild</B> </DT>
<DD>Selects the first child
of the node. </DD>
<DT><B>lastchild</B> </DT>
<DD>Selects the last child of the node. </DD>
<DT><B>next</B> </DT>
<DD>Selects
the next node in preorder to the node. </DD>
<DT><B>nextsibling</B> </DT>
<DD>Selects the next sibling
of the node. </DD>
<DT><B>parent</B> </DT>
<DD>Selects the parent of the node. </DD>
<DT><B>previous</B> </DT>
<DD>Selects
the previous node in preorder to the node. </DD>
<DT><B>prevsibling</B> </DT>
<DD>Selects the previous
sibling of the node. </DD>
<DT>"<I>label</I>" </DT>
<DD>Selects the node whose label is <I>label</I>. Enclosing
<I>label</I> in quotes indicates to always search for a node by its label (for
example, even if the node is labeled "parent"). </DD>
</DL>
</blockquote>
<P>
It's an error the node can't
be found. For example, <B>lastchild</B> and <B>firstchild</B> will generate errors if
the node has no children. The exception to this is the <B>index</B> operation.
You can use <B>index</B> to test if a modifier is valid.
<H2><A NAME="sect8" HREF="#toc8">Tree Operations</A></H2>
Once you
create a tree object, you can use its Tcl command to query or modify it.
The general form is <BR>
<P>
<CODE><I>treeName</I> <I>operation</I> ?<I>arg</I>?...<BR>
</CODE><P>Both <I>operation</I> and its arguments determine the exact behavior of the command.
The operations available for trees are listed below.
<DL>
<DT><I>treeName</I> <B>ancestor</B>
<I>node1</I> <I>node2</I> </DT>
<DD>Returns the mutual ancestor of the two nodes <I>node1</I> and <I>node2</I>.
The ancestor can be one of the two nodes. For example, if <I>node1</I> and <I>node2</I>
are the same nodes, their ancestor is <I>node1</I>. </DD>
<DT><I>treeName</I> <B>apply</B> <I>node</I> ?<I>switches</I>?
</DT>
<DD>Runs commands for all nodes matching the criteria given by <I>switches</I> for
the subtree designated by <I>node</I>. By default all nodes match, but you can
set switches to narrow the match. This operation differs from <B>find</B> in two
ways: 1) Tcl commands can be invoked both pre- and post-traversal of a node
and 2) the tree is always traversed in depth first order. <P>
The <B>-exact</B>, <B>-glob</B>,
and <B>-regexp</B> switches indicate both what kind of pattern matching to perform
and the pattern. Pattern matching is done, by default, against each node's
label. But if the <B>-path</B> switch is present, it will match the full path of
the node (a list containing the labels of the node's ancestors too). If
the <B>-key</B> switch is used, it designates the data field to be matched. <P>
The
valid switches are listed below: <blockquote></DD>
<DT><B>-depth</B> <I>number</I> </DT>
<DD>Descend at most <I>number</I> (a
non-negative integer) levels If <I>number</I> is <I>1</I> this means only apply the tests
to the children of <I>node</I>. </DD>
<DT><B>-exact</B> <I>string</I> </DT>
<DD>Matches each node using <I>string</I>. The
node must match <I>string</I> exactly. </DD>
<DT><B>-glob</B> <I>string</I> </DT>
<DD>Test each node to <I>string</I> using
global pattern matching. Matching is done in a fashion similar to that
used by the C-shell. </DD>
<DT><B>-invert</B> </DT>
<DD>Select non-matching nodes. Any node that <I>doesn't</I>
match the given criteria will be selected. </DD>
<DT><B>-key</B> <I>key</I> </DT>
<DD>If pattern matching is
selected (using the <B>-exact</B>, <B>-glob</B>, or <B>-regexp</B> switches), compare the values
of the data field keyed by <I>key</I> instead of the node's label. If no pattern
matching switches are set, then any node with this data key will match.
</DD>
<DT><B>-leafonly</B> </DT>
<DD>Only test nodes with no children. </DD>
<DT><B>-nocase</B> </DT>
<DD>Ignore case when matching
patterns. </DD>
<DT><B>-path</B> </DT>
<DD>Use the node's full path when comparing nodes. </DD>
<DT><B>-precommand</B> <I>command</I>
</DT>
<DD>Invoke <I>command</I> for each matching node. Before <I>command</I> is invoked, the id
of the node is appended. You can control processing by the return value
of <I>command</I>. If <I>command</I> generates an error, processing stops and the <B>find</B>
operation returns an error. But if <I>command</I> returns <B>break</B>, then processing
stops, no error is generated. If <I>command</I> returns <B>continue</B>, then processing
stops on that subtree and continues on the next. </DD>
<DT><B>-postcommand</B> <I>command</I> </DT>
<DD>Invoke
<I>command</I> for each matching node. Before <I>command</I> is invoked, the id of the
node is appended. You can control processing by the return value of <I>command</I>.
If <I>command</I> generates an error, processing stops and the <B>find</B> operation
returns an error. But if <I>command</I> returns <B>break</B>, then processing stops,
no error is generated. If <I>command</I> returns <B>continue</B>, then processing stops
on that subtree and continues on the next. </DD>
<DT><B>-regexp</B> <I>string</I> </DT>
<DD>Test each node
using <I>string</I> as a regular expression pattern. </DD>
<DT><B>-tag</B> <I>string</I> </DT>
<DD>Only test nodes
that have the tag <I>string</I>. </DD>
</DL>
</blockquote>
<DL>
<DT><I>treeName</I> <B>attach</B> <I>treeObject</I> </DT>
<DD>Attaches to an existing
tree object <I>treeObject</I>. This is for cases where the tree object was previously
created via the C API. The current tree associated with <I>treeName</I> is discarded.
In addition, the current set of tags, notifier events, and traces are
removed. </DD>
<DT><I>treeName</I> <B>children</B> <I>node</I> </DT>
<DD>Returns a list of children for <I>node</I>. If
<I>node</I> is a leaf, then an empty string is returned. </DD>
<DT><I>treeName</I> <B>copy</B> <I>srcNode</I>
?<I>destTree</I>? <I>destNode</I> ?<I>switches</I>? </DT>
<DD>Copies <I>srcNode</I> into <I>destNode</I>. Both nodes
<I>srcNode</I> and <I>destNode</I> must already exist. If <I>destTree</I> argument is present,
it indicates the name of the destination tree. By default both the source
and destination trees are the same. The valid <I>switches</I> are listed below:
<blockquote></DD>
<DT><B>-overwrite</B> </DT>
<DD>Overwrite nodes that already exist. Normally nodes are always
created, even if there already exists a node by the same name. This switch
indicates to add or overwrite the node's data fields. </DD>
<DT><B>-recurse</B> </DT>
<DD>Recursively
copy all the subtrees of <I>srcNode</I> as well. In this case, <I>srcNode</I> can't be
an ancestor of <I>destNode</I> as it would result in a cyclic copy. </DD>
<DT><B>-tags</B> </DT>
<DD>Copy tag
inforation. Normally the following node is copied: its label and data
fields. This indicates to copy tags as well. </DD>
</DL>
</blockquote>
<DL>
<DT><I>treeName</I> <B>degree</B> <I>node</I> </DT>
<DD>Returns
the number of children of <I>node</I>. </DD>
<DT><I>treeName</I> <B>delete</B> <I>node</I>... </DT>
<DD>Recursively deletes
one or more nodes from the tree. The node and all its descendants are
removed. The one exception is the root node. In this case, only its descendants
are removed. The root node will remain. Any tags or traces on the nodes
are released. </DD>
<DT><I>treeName</I> <B>depth</B> <I>node</I> </DT>
<DD>Returns the depth of the node. The depth
is the number of steps from the node to the root of the tree. The depth
of the root node is <I>0</I>. </DD>
<DT><I>treeName</I> <B>dump</B> <I>node</I> </DT>
<DD>Returns a list of the paths and
respective data for <I>node</I> and its descendants. The subtree designated by
<I>node</I> is traversed returning the following information for each node: 1)
the node's path relative to <I>node</I>, 2) a sublist key value pairs representing
the node's data fields, and 3) a sublist of tags. This list returned can
be used later to copy or restore the tree with the <B>restore</B> operation. </DD>
<DT><I>treeName</I>
<B>dumpfile</B> <I>node</I> <I>fileName</I> </DT>
<DD>Writes a list of the paths and respective data for
<I>node</I> and its descendants to the given file <I>fileName</I>. The subtree designated
by <I>node</I> is traversed returning the following information for each node:
1) the node's path relative to <I>node</I>, 2) a sublist key value pairs representing
the node's data fields, and 3) a sublist of tags. This list returned can
be used later to copy or restore the tree with the <B>restore</B> operation. </DD>
<DT><I>treeName</I>
<B>exists</B> <I>node</I> ?<I>key</I>? </DT>
<DD>Indicates if <I>node</I> exists in the tree. If a <I>key</I> argument
is present then the command also indicates if the named data field exists.
</DD>
<DT><I>treeName</I> <B>find</B> <I>node</I> ?<I>switches</I>? </DT>
<DD>Finds for all nodes matching the criteria
given by <I>switches</I> for the subtree designated by <I>node</I>. A list of the selected
nodes is returned. By default all nodes match, but you can set switches
to narrow the match. <P>
The <B>-exact</B>, <B>-glob</B>, and <B>-regexp</B> switches indicate both
what kind of pattern matching to perform and the pattern. Pattern matching
is done, by default, against each node's label. But if the <B>-path</B> switch is
present, it will match the full path of the node. If the <B>-key</B> switch is
used, it designates the data field to be matched. <P>
The order in which
the nodes are traversed is controlled by the <B>-order</B> switch. The possible
orderings are <B>preorder</B>, <B>postorder</B>, <B>inorder</B>, and <B>breadthfirst</B>. The default
is <B>postorder</B>. <P>
The valid switches are listed below: <blockquote></DD>
<DT><B>-addtag</B> <I>string</I> </DT>
<DD>Add the
tag <I>string</I> to each selected node. </DD>
<DT><B>-count</B> <I>number</I> </DT>
<DD>Stop processing after <I>number</I>
(a positive integer) matches. </DD>
<DT><B>-depth</B> <I>number</I> </DT>
<DD>Descend at most <I>number</I> (a non-negative
integer) levels If <I>number</I> is <I>1</I> this means only apply the tests to the children
of <I>node</I>. </DD>
<DT><B>-exact</B> <I>string</I> </DT>
<DD>Matches each node using <I>string</I>. The node must match
<I>string</I> exactly. </DD>
<DT><B>-exec</B> <I>command</I> </DT>
<DD>Invoke <I>command</I> for each matching node. Before
<I>command</I> is invoked, the id of the node is appended. You can control processing
by the return value of <I>command</I>. If <I>command</I> generates an error, processing
stops and the <B>find</B> operation returns an error. But if <I>command</I> returns
<B>break</B>, then processing stops, no error is generated. If <I>command</I> returns
<B>continue</B>, then processing stops on that subtree and continues on the next.
</DD>
<DT><B>-glob</B> <I>string</I> </DT>
<DD>Test each node to <I>string</I> using global pattern matching. Matching
is done in a fashion similar to that used by the C-shell. </DD>
<DT><B>-invert</B> </DT>
<DD>Select non-matching
nodes. Any node that <I>doesn't</I> match the given criteria will be selected. </DD>
<DT><B>-key</B>
<I>key</I> </DT>
<DD>If pattern matching is selected (using the <B>-exact</B>, <B>-glob</B>, or <B>-regexp</B> switches),
compare the values of the data field keyed by <I>key</I> instead of the node's
label. If no pattern matching switches are set, then any node with this
data key will match. </DD>
<DT><B>-leafonly</B> </DT>
<DD>Only test nodes with no children. </DD>
<DT><B>-nocase</B> </DT>
<DD>Ignore
case when matching patterns. </DD>
<DT><B>-order</B> <I>string</I> </DT>
<DD>Traverse the tree and process
nodes according to <I>string</I>. <I>String</I> can be one of the following: <blockquote></DD>
<DT><B>breadthfirst</B>
</DT>
<DD>Process the node and the subtrees at each sucessive level. Each node on
a level is processed before going to the next level. </DD>
<DT><B>inorder</B> </DT>
<DD>Recursively
process the nodes of the first subtree, the node itself, and any the remaining
subtrees. </DD>
<DT><B>postorder</B> </DT>
<DD>Recursively process all subtrees before the node. </DD>
<DT><B>preorder</B>
</DT>
<DD>Recursively process the node first, then any subtrees. </DD>
</DL>
</blockquote>
<DL>
<DT><B>-path</B> </DT>
<DD>Use the node's
full path when comparing nodes. </DD>
<DT><B>-regexp</B> <I>string</I> </DT>
<DD>Test each node using <I>string</I>
as a regular expression pattern. </DD>
<DT><B>-tag</B> <I>string</I> </DT>
<DD>Only test nodes that have the
tag <I>string</I>. </DD>
</DL>
</blockquote>
<DL>
<DT><I>treeName</I> <B>findchild</B> <I>node</I> <I>label</I> </DT>
<DD>Searches for a child node Ilabel
in <I>node</I>. The id of the child node is returned if found. Otherwise <I>-1</I> is
returned. </DD>
<DT><I>treeName</I> <B>firstchild</B> <I>node</I> </DT>
<DD>Returns the id of the first child in
the <I>node</I>'s list of subtrees. If <I>node</I> is a leaf (has no children), then
<I>-1</I> is returned. </DD>
<DT><I>treeName</I> <B>get</B> <I>node</I> ?<I>key</I>? ?<I>defaultValue</I>? </DT>
<DD>Returns a list of
key-value pairs of data for the node. If <I>key</I> is present, then onlyx the
value for that particular data field is returned. It's normally an error
if <I>node</I> does not contain the data field <I>key</I>. But if you provide a <I>defaultValue</I>
argument, this value is returned instead (<I>node</I> will still not contain <I>key</I>).
This feature can be used to access a data field of <I>node</I> without first
testing if it exists. This operation may trigger <B>read</B> data traces. </DD>
<DT><I>treeName</I>
<B>index</B> <I>node</I> </DT>
<DD>Returns the id of <I>node</I>. If <I>node</I> is a tag, it can only specify
one node. If <I>node</I> does not represent a valid node id or tag, or has modifiers
that are invalid, then <I>-1</I> is returned. </DD>
<DT><I>treeName</I> <B>insert</B> <I>parent</I> ?<I>switches</I>?
</DT>
<DD>Inserts a new node into parent node <I>parent</I>. The id of the new node is
returned. The following switches are available: <blockquote></DD>
<DT><B>-at</B> <I>number</I> </DT>
<DD>Inserts the
node into <I>parent</I>'s list of children at position <I>number</I>. The default is
to append <I>node</I>. </DD>
<DT><B>-data</B> <I>dataList</I> </DT>
<DD>Sets the value for each data field in <I>dataList</I>
for the new node. <I>DataList</I> is a list of key-value pairs. </DD>
<DT><B>-label</B> <I>string</I> </DT>
<DD>Designates
the labels of the node as <I>string</I>. By default, nodes are labeled as <I>node0</I>,
<I>node1</I>, etc. </DD>
<DT><B>-tags</B> <I>tagList</I> </DT>
<DD>Adds each tag in <I>tagList</I> to the new node. <I>TagList</I>
is a list of tags, so be careful if a tag has embedded space. </DD>
</DL>
</blockquote>
<DL>
<DT><I>treeName</I> <B>is</B>
<I>property</I> <I>args</I> </DT>
<DD>Indicates the property of a node. Both <I>property</I> and <I>args</I>
determine the property being tested. Returns <I>1</I> if true and <I>0</I> otherwise.
The following <I>property</I> and <I>args</I> are valid: <blockquote></DD>
<DT><B>ancestor</B> <I>node1</I> <I>node2</I> </DT>
<DD>Indicates
if <I>node1</I> is an ancestor of <I>node2</I>. </DD>
<DT><B>before</B> <I>node1</I> <I>node2</I> </DT>
<DD>Indicates if <I>node1</I>
is before <I>node2</I> in depth first traversal. </DD>
<DT><B>leaf</B> <I>node</I> </DT>
<DD>Indicates if <I>node</I> is
a leaf (it has no subtrees). </DD>
<DT><B>root</B> <I>node</I> </DT>
<DD>Indicates if <I>node</I> is the designated
root. This can be changed by the <B>root</B> operation. </DD>
</DL>
</blockquote>
<DL>
<DT><I>treeName</I> <B>label</B> <I>node</I> ?<I>newLabel</I>?
</DT>
<DD>Returns the label of the node designated by <I>node</I>. If <I>newLabel</I> is present,
the node is relabeled using it as the new label. </DD>
<DT><I>treeName</I> <B>lastchild</B> <I>node</I>
</DT>
<DD>Returns the id of the last child in the <I>node</I>'s list of subtrees. If <I>node</I>
is a leaf (has no children), then <I>-1</I> is returned. </DD>
<DT><I>treeName</I> <B>move</B> <I>node</I> <I>newParent</I>
?<I>switches</I>? </DT>
<DD>Moves <I>node</I> into <I>newParent</I>. <I>Node</I> is appended to the list children
of <I>newParent</I>. <I>Node</I> can not be an ancestor of <I>newParent</I>. The valid flags
for <I>switches</I> are described below. <blockquote></DD>
<DT><B>-after</B> <I>child</I> </DT>
<DD>Position <I>node</I> after <I>child</I>.
The node <I>child</I> must be a child of <I>newParent</I>. </DD>
<DT><B>-at</B> <I>number</I> </DT>
<DD>Inserts <I>node</I> into
<I>parent</I>'s list of children at position <I>number</I>. The default is to append the
node. </DD>
<DT><B>-before</B> <I>child</I> </DT>
<DD>Position <I>node</I> before <I>child</I>. The node <I>child</I> must be a
child of <I>newParent</I>. </DD>
</DL>
</blockquote>
<DL>
<DT><I>treeName</I> <B>next</B> <I>node</I> </DT>
<DD>Returns the next node from <I>node</I>
in a preorder traversal. If <I>node</I> is the last node in the tree, then <I>-1</I> is
returned. </DD>
<DT><I>treeName</I> <B>nextsibling</B> <I>node</I> </DT>
<DD>Returns the node representing the next
subtree from <I>node</I> in its parent's list of children. If <I>node</I> is the last
child, then <I>-1</I> is returned. </DD>
<DT><I>treeName</I> <B>notify</B> <I>args</I> </DT>
<DD>Manages notification events
that indicate that the tree structure has been changed. See the <FONT SIZE=-1><B>NOTIFY
OPERATIONS</B></FONT>
section below. </DD>
<DT><I>treeName</I> <B>parent</B> <I>node</I> </DT>
<DD>Returns the parent node
of <I>node</I>. If <I>node</I> is the root of the tree, then <I>-1</I> is returned. </DD>
<DT><I>treeName</I>
<B>path</B> <I>node</I> </DT>
<DD>Returns the full path (from root) of <I>node</I>. </DD>
<DT><I>treeName</I> <B>position</B> <I>node</I>
</DT>
<DD>Returns the position of the node in its parent's list of children. Positions
are numbered from 0. The position of the root node is always 0. </DD>
<DT><I>treeName</I>
<B>previous</B> <I>node</I> </DT>
<DD>Returns the previous node from <I>node</I> in a preorder traversal.
If <I>node</I> is the root of the tree, then <I>-1</I> is returned. </DD>
<DT><I>treeName</I> <B>prevsibling</B>
<I>node</I> </DT>
<DD>Returns the node representing the previous subtree from <I>node</I> in its
parent's list of children. If <I>node</I> is the first child, then <I>-1</I> is returned.
</DD>
<DT><I>treeName</I> <B>restore</B> <I>node</I> <I>dataString</I> <I>switches</I> </DT>
<DD>Performs the inverse function
of the <B>dump</B> operation, restoring nodes to the tree. The format of <I>dataString</I>
is exactly what is returned by the <B>dump</B> operation. It's a list containing
information for each node to be restored. The information consists of 1)
the relative path of the node, 2) a sublist of key value pairs representing
the node's data, and 3) a list of tags for the node. Nodes are created
starting from <I>node</I>. Nodes can be listed in any order. If a node's path
describes ancestor nodes that do not already exist, they are automatically
created. The valid <I>switches</I> are listed below: <blockquote></DD>
<DT><B>-overwrite</B> </DT>
<DD>Overwrite nodes
that already exist. Normally nodes are always created, even if there already
exists a node by the same name. This switch indicates to add or overwrite
the node's data fields. </DD>
</DL>
</blockquote>
<DL>
<DT><I>treeName</I> <B>restorefile</B> <I>node</I> <I>fileName</I> <I>switches</I> </DT>
<DD>Performs
the inverse function of the <B>dumpfile</B> operation, restoring nodes to the
tree from the file <I>fileName</I>. The format of <I>fileName</I> is exactly what is
returned by the <B>dumpfile</B> operation. It's a list containing information
for each node to be restored. The information consists of 1) the relative
path of the node, 2) a sublist of key value pairs representing the node's
data, and 3) a list of tags for the node. Nodes are created starting
from <I>node</I>. Nodes can be listed in any order. If a node's path describes
ancestor nodes that do not already exist, they are automatically created.
The valid <I>switches</I> are listed below: <blockquote></DD>
<DT><B>-overwrite</B> </DT>
<DD>Overwrite nodes that already
exist. Normally nodes are always created, even if there already exists
a node by the same name. This switch indicates to add or overwrite the
node's data fields. </DD>
</DL>
</blockquote>
<DL>
<DT><I>treeName</I> <B>root</B> ?<I>node</I>? </DT>
<DD>Returns the id of the root node.
Normally this is node <I>0</I>. If a <I>node</I> argument is provided, it will become
the new root of the tree. This lets you temporarily work within a subset
of the tree. Changing root affects operations such as <B>next</B>, <B>path</B>, <B>previous</B>,
etc. </DD>
<DT><I>treeName</I> <B>set</B> <I>node</I> <I>key value</I> ?<I>key value</I>...? </DT>
<DD>Sets one or more data fields
in <I>node</I>. <I>Node</I> may be a tag that represents several nodes. <I>Key</I> is the name
of the data field to be set and <I>value</I> is its respective value. This operation
may trigger <B>write</B> and <B>create</B> data traces. </DD>
<DT><I>treeName</I> <B>size</B> <I>node</I> </DT>
<DD>Returns the
number of nodes in the subtree. This includes the node and all its descendants.
The size of a leaf node is 1. </DD>
<DT><I>treeName</I> <B>sort</B> <I>node</I> ?<I>switches</I>? </DT>
<DD><blockquote></DD>
<DT><B>-ascii</B> </DT>
<DD>Compare
strings using the ASCII collation order. </DD>
<DT><B>-command</B> <I>string</I> </DT>
<DD>Use command <I>string</I>
as a comparison command. To compare two elements, evaluate a Tcl script
consisting of command with the two elements appended as additional arguments.
The script should return an integer less than, equal to, or greater than
zero if the first element is to be considered less than, equal to, or greater
than the second, respectively. </DD>
<DT><B>-decreasing</B> </DT>
<DD>Sort in decreasing order (largest
items come first). </DD>
<DT><B>-dictionary</B> </DT>
<DD>Compare strings using a dictionary-style comparison.
This is the same as <B>-ascii</B> except (a) case is ignored except as a tie-breaker
and (b) if two strings contain embedded numbers, the numbers compare as
integers, not characters. For example, in <B>-dictionary</B> mode, bigBoy sorts
between bigbang and bigboy, and x10y sorts between x9y and x11y. </DD>
<DT><B>-integer</B>
</DT>
<DD>Compare the nodes as integers. </DD>
<DT><B>-key</B> <I>string</I> </DT>
<DD>Sort based upon the node's data
field keyed by <I>string</I>. Normally nodes are sorted according to their label.
</DD>
<DT><B>-path</B> </DT>
<DD>Compare the full path of each node. The default is to compare only
its label. </DD>
<DT><B>-real</B> </DT>
<DD>Compare the nodes as real numbers. </DD>
<DT><B>-recurse</B> </DT>
<DD>Recursively sort
the entire subtree rooted at <I>node</I>. </DD>
<DT><B>-reorder</B> </DT>
<DD>Recursively sort subtrees for
each node. <B>Warning</B>. Unlike the normal flat sort, where a list of nodes
is returned, this will reorder the tree. </DD>
</DL>
</blockquote>
<DL>
<DT><I>treeName</I> <B>tag</B> <I>args</I> </DT>
<DD>Manages tags
for the tree object. See the <FONT SIZE=-1><B>TAG OPERATIONS</B></FONT>
section below. </DD>
<DT><I>treeName</I> <B>trace</B>
<I>args</I> </DT>
<DD>Manages traces for data fields in the tree object. Traces cause Tcl
commands to be executed whenever a data field of a node is created, read,
written, or unset. Traces can be set for a specific node or a tag, representing
possibly many nodes. See the <FONT SIZE=-1><B>TRACE OPERATIONS</B></FONT>
section below. </DD>
<DT><I>treeName</I> <B>unset</B>
<I>node</I> <I>key</I>... </DT>
<DD>Removes one or more data fields from <I>node</I>. <I>Node</I> may be a tag that
represents several nodes. <I>Key</I> is the name of the data field to be removed.
It's not an error is <I>node</I> does not contain <I>key</I>. This operation may trigger
<B>unset</B> data traces. </DD>
</DL>
</blockquote>
<H2><A NAME="sect9" HREF="#toc9">Tag Operations</A></H2>
Tags are a general means of selecting and
marking nodes in the tree. A tag is just a string of characters, and it
may take any form except that of an integer. The same tag may be associated
with many different nodes. <P>
There are two built-in tags: The tag <B>all</B> is
implicitly associated with every node in the tree. It may be used to invoke
operations on all the nodes in the tree. The tag <B>root</B> is managed automatically
by the tree object. It specifies the node that is currently set as the
root of the tree. <P>
Most tree operations use tags. And several operations
let you operate on multiple nodes at once. For example, you can use the
<B>set</B> operation with the tag <B>all</B> to set a data field in for all nodes in
the tree. <P>
Tags are invoked by the <B>tag</B> operation. The general form is <BR>
<P>
<CODE><I>treeName</I> <B>tag</B> <I>operation</I> ?<I>arg</I>?...<BR>
</CODE><P>Both <I>operation</I> and its arguments determine the exact behavior of the command.
The operations available for tags are listed below.
<DL>
<DT><I>treeName</I> <B>tag add</B> <I>string</I>
<I>node</I>... </DT>
<DD>Adds the tag <I>string</I> to one of more nodes. </DD>
<DT><I>treeName</I> <B>tag delete</B> <I>string</I>
<I>node</I>... </DT>
<DD>Deletes the tag <I>string</I> from one or more nodes. </DD>
<DT><I>treeName</I> <B>tag forget</B>
<I>string</I> </DT>
<DD>Removes the tag <I>string</I> from all nodes. It's not an error if no nodes
are tagged as <I>string</I>. </DD>
<DT><I>treeName</I> <B>tag names</B> ?<I>node</I>? </DT>
<DD>Returns a list of tags used
by the tree. If a <I>node</I> argument is present, only those tags used by <I>node</I>
are returned. </DD>
<DT><I>treeName</I> <B>tag nodes</B> <I>string</I> </DT>
<DD>Returns a list of nodes that have
the tag <I>string</I>. If no node is tagged as <I>string</I>, then an empty string is
returned. </DD>
</DL>
<H2><A NAME="sect10" HREF="#toc10">Trace Operations</A></H2>
Data fields can be traced much in the same way
that you can trace Tcl variables. Data traces cause Tcl commands to be
executed whenever a particular data field of a node is created, read, written,
or unset. A trace can apply to one or more nodes. You can trace a specific
node by using its id, or a group of nodes by a their tag. <P>
The tree's <B>get</B>,
<B>set</B>, and <B>unset</B> operations can trigger various traces. The <B>get</B> operation
can cause a <I>read</I> trace to fire. The <B>set</B> operation causes a <I>write</I> trace
to fire. And if the data field is written for the first time, you will
also get a <I>create</I> trace. The <B>unset</B> operation triggers <I>unset</I> traces. <P>
Data
traces are invoked by the <B>trace</B> operation. The general form is <BR>
<P>
<CODE><I>treeName</I> <B>trace</B> <I>operation</I> ?<I>arg</I>?...<BR>
</CODE><P>Both <I>operation</I> and its arguments determine the exact behavior of the command.
The operations available for traces are listed below.
<DL>
<DT><I>treeName</I> <B>trace create</B>
<I>node</I> <I>key</I> <I>ops</I> <I>command</I> </DT>
<DD>Creates a trace for <I>node</I> on data field <I>key</I>. <I>Node</I> can
refer to more than one node (for example, the tag <B>all</B>). If <I>node</I> is a tag,
any node with that tag can possibly trigger a trace, invoking <I>command</I>.
<I>Command</I> is command prefix, typically a procedure name. Whenever a trace
is triggered, four arguments are appended to <I>command</I> before it is invoked:
<I>treeName</I>, id of the node, <I>key</I> and, <I>ops</I>. Note that no nodes need have the
field <I>key</I>. A trace identifier in the form "<I>trace0</I>", "<I>trace1</I>", etc. is returned.
<P>
<I>Ops</I> indicates which operations are of interest, and consists of one or
more of the following letters: <blockquote></DD>
<DT><B>r</B> </DT>
<DD>Invoke <I>command</I> whenever <I>key</I> is read. Both
read and write traces are temporarily disabled when <I>command</I> is executed.
</DD>
<DT><B>w</B> </DT>
<DD>Invoke <I>command</I> whenever <I>key</I> is written. Both read and write traces are
temporarily disabled when <I>command</I> is executed. </DD>
<DT><B>c</B> </DT>
<DD>Invoke <I>command</I> whenever
<I>key</I> is created. </DD>
<DT><B>u</B> </DT>
<DD>Invoke <I>command</I> whenever <I>key</I> is unset. Data fields are
typically unset with the <B>unset</B> command. Data fields are also unset when
the tree is released, but all traces are disabled prior to that. <P>
</DD>
</DL>
</blockquote>
<DL>
<DT><I>treeName</I>
<B>trace delete</B> <I>traceId</I>... </DT>
<DD>Deletes one of more traces. <I>TraceId</I> is the trace identifier
returned by the <B>trace create</B> operation. </DD>
<DT><I>treeName</I> <B>trace info</B> <I>traceId</I> </DT>
<DD>Returns
information about the trace <I>traceId</I>. <I>TraceId</I> is a trace identifier previously
returned by the <B>trace create</B> operation. It's the same information specified
for the <B>trace create</B> operation. It consists of the node id or tag, data
field key, a string of letters indicating the operations that are traced
(it's in the same form as <I>ops</I>) and, the command prefix. </DD>
<DT><I>treeName</I> <B>trace names</B>
</DT>
<DD>Returns a list of identifers for all the current traces. </DD>
</DL>
<H2><A NAME="sect11" HREF="#toc11">Notify Operations</A></H2>
Tree
objects can be shared among many clients, such as a <B>hiertable</B> widget. Any
client can create or delete nodes, sorting the tree, etc. You can request
to be notified whenever these events occur. Notify events cause Tcl commands
to be executed whenever the tree structure is changed. <P>
Notifications are
handled by the <B>notify</B> operation. The general form is <BR>
<P>
<CODE><I>treeName</I> <B>notify</B> <I>operation</I> ?<I>arg</I>?...<BR>
</CODE><P>Both <I>operation</I> and its arguments determine the exact behavior of the command.
The operations available for events are listed below.
<DL>
<DT><I>treeName</I> <B>notify create</B>
?<I>switches</I>? <I>command</I> ?<I>args</I>?... </DT>
<DD>Creates a notifier for the tree. A notify identifier
in the form "<I>notify0</I>", "<I>notify1</I>", etc. is returned. <P>
<I>Command</I> and <I>args</I> are
saved and invoked whenever the tree structure is changed (according to
<I>switches</I>). Two arguments are appended to <I>command</I> and <I>args</I> before it's invoked:
the id of the node and a string representing the type of event that occured.
One of more switches can be set to indicate the events that are of interest.
The valid switches are as follows: <blockquote></DD>
<DT><B>-create</B> </DT>
<DD>Invoke <I>command</I> whenever a new
node has been added. </DD>
<DT><B>-delete</B> </DT>
<DD>Invoke <I>command</I> whenever a node has been deleted.
</DD>
<DT><B>-move</B> </DT>
<DD>Invoke <I>command</I> whenever a node has been moved. </DD>
<DT><B>-sort</B> </DT>
<DD>Invoke <I>command</I>
whenever the tree has been sorted and reordered. </DD>
<DT><B>-relabel</B> </DT>
<DD>Invoke <I>command</I>
whenever a node has been relabeled. </DD>
<DT><B>-allevents</B> </DT>
<DD>Invoke <I>command</I> whenever any
of the above events occur. </DD>
<DT><B>-whenidle</B> </DT>
<DD>When an event occurs don't invoke <I>command</I>
immediately, but queue it to be run the next time the event loop is entered
and there are no events to process. If subsequent events occur before
the event loop is entered, <I>command</I> will still be invoked only once. </DD>
</DL>
</blockquote>
<DL>
<DT><I>treeName</I>
<B>notify delete</B> <I>notifyId</I> </DT>
<DD>Deletes one or more notifiers from the tree. <I>NotifyId</I>
is the notifier identifier returned by the <B>notify create</B> operation. </DD>
<DT><I>treeName</I>
<B>notify info</B> <I>notifyId</I> </DT>
<DD>Returns information about the notify event <I>notifyId</I>.
<I>NotifyId</I> is a notify identifier previously returned by the <B>notify create</B>
operation. It's the same information specified for the <B>notify create</B> operation.
It consists of the notify id, a sublist of event flags (it's in the same
form as <I>flags</I>) and, the command prefix. </DD>
<DT><I>treeName</I> <B>notify names</B> </DT>
<DD>Returns a
list of identifers for all the current notifiers. </DD>
</DL>
<H2><A NAME="sect12" HREF="#toc12">C Language API</A></H2>
Blt_TreeApply,
Blt_TreeApplyBFS, Blt_TreeApplyDFS, Blt_TreeChangeRoot, Blt_TreeCreate,
Blt_TreeCreateEventHandler, Blt_TreeCreateNode, Blt_TreeCreateTrace,
Blt_TreeDeleteEventHandler, Blt_TreeDeleteNode, Blt_TreeDeleteTrace,
Blt_TreeExists, Blt_TreeFindChild, Blt_TreeFirstChild, Blt_TreeFirstKey,
Blt_TreeGetNode, Blt_TreeGetToken, Blt_TreeGetValue, Blt_TreeIsAncestor,
Blt_TreeIsBefore, Blt_TreeIsLeaf, Blt_TreeLastChild, Blt_TreeMoveNode,
Blt_TreeName, Blt_TreeNextKey, Blt_TreeNextNode, Blt_TreeNextSibling,
Blt_TreeNodeDegree, Blt_TreeNodeDepth, Blt_TreeNodeId, Blt_TreeNodeLabel,
Blt_TreeNodeParent, Blt_TreePrevNode, Blt_TreePrevSibling, Blt_TreeRelabelNode,
Blt_TreeReleaseToken, Blt_TreeRootNode, Blt_TreeSetValue, Blt_TreeSize,
Blt_TreeSortNode, and Blt_TreeUnsetValue.
<H2><A NAME="sect13" HREF="#toc13">Keywords</A></H2>
tree, hiertable, widget
<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">Description</A></LI>
<LI><A NAME="toc3" HREF="#sect3">Introduction</A></LI>
<LI><A NAME="toc4" HREF="#sect4">Example</A></LI>
<LI><A NAME="toc5" HREF="#sect5">Syntax</A></LI>
<LI><A NAME="toc6" HREF="#sect6">Node IDs and Tags</A></LI>
<LI><A NAME="toc7" HREF="#sect7">Node Modifiers</A></LI>
<LI><A NAME="toc8" HREF="#sect8">Tree Operations</A></LI>
<LI><A NAME="toc9" HREF="#sect9">Tag Operations</A></LI>
<LI><A NAME="toc10" HREF="#sect10">Trace Operations</A></LI>
<LI><A NAME="toc11" HREF="#sect11">Notify Operations</A></LI>
<LI><A NAME="toc12" HREF="#sect12">C Language API</A></LI>
<LI><A NAME="toc13" HREF="#sect13">Keywords</A></LI>
</UL>
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