ids/8/306.txt

@@ WIP

IFClsXDef:
  @IFQName: SerialWalker
  @ClsQName: ManakaiDOMSerialWalker

  @enDesc:
    {ISSUE::
      Better name?
    }

    A <IF::SerialWalker> object can be used to traverse
    the subtree rooted by a node in document order.
    Unlike <IF::TreeWalker> and <IF::NodeIterator>, the
    <IF::SerialWalker> object cannot go back toward
    nodes that had already been seen.  The
    <IF::SerialWalker>, however, revisits a node after its
    children are visited.  This might be useful when
    an application wants to serialize a subtree in a format
    where delimiter and / or terminator should be inserted
    between and / or after nodes.

    How the <IF::SerialWalker> works is defined by the following
    reference algorithm.  An implementation does not have to
    implement this exact algorithm, but it <kwd:MUST> implement
    its method so that it has the same effect as the
    reference algorithm when the underlying subtree has not
    been modified.

    At the time of creation of the <IF::SerialWalker>, 
    the implementation <kwd:MUST> prepare a queue and
    <kwd:MUST> initialize it by pushing the <A::SerialWalker.root> node.

    {P:: When the <M::SerialWalker.nextNode> method is invoked,

       - If the queue is empty, the method <kwd:MUST> return
         <DOM::null>.  It <kwd:MUST-NOT> change 
         <A::SerialWalker.currentNode>, <A::SerialWalker.currentPhase>,
         and <A::SerialWalker.currentIndex> attributes.

       {LI:: Otherwise, 

          - Shift a node from the queue.  If the node has
            the phase value, the method <kwd:MUST> return
            the node.  In addition, it <kwd:MUST> set
            the <A::SerialWalker.currentNode> attribute to the node,
            the <A::SerialWalker.currentPhase> attribute to
            the associated phase value, and the
            <A::SerialWalker.currentIndex> attribute to
            the integer value that is large by one than
            the most recent <A::SerialWalker.currentIndex> value
            when the <A::SerialWalker.currentNode> was
            same as the shiftted node.  If it is the first time
            the node is set to the <A::SerialWalker.currentNode>
            attribute, the <A::SerialWalker.currentIndex>
            attribute <kwd:MUST> set to zero.

          {LI:: Otherwise, determine whether the shifted node
                should be accepted or not, using 
                <A::SerialWalker.expandEntityReferences>,
                <A::SerialWalker.whatToShow>, and
                <A::SerialWalker.filter> attributes, as defined
                for the <IF::TreeWalker> interface.

             {LI:: If the node is <C::NodeFilter.FILTER_ACCEPT>ed,

                = Prepend the node to the queue, with
                  phase value set to <C::SerialWalker.POST_PHASE>.
 
                = Prepend the child nodes of the node, if any,
                  to the queue keeping the document order,
                  without phase value.  That is, the first child
                  <kwd:MUST> be located at the top (first
                  position) of the queue.

                = Prepend the node to the queue, with
                  phase value set to <C::SerialWalker.PRE_PHASE>.
               
                = If the node has a previous sibling in the logical view,
                  preprend the parent node of the node in the logical
                  view, with phase value set to <C::SerialWalker.IN_PHASE>.

                = Invoke the algorithm recursively.

             }

             {LI:: If the node is <C::NodeFilter.FILTER_SKIP>ped,

                = Prepend the child nodes of the node, if any,
                  to the queue keeping the document order,
                  without phase value.  That is, the first child
                  <kwd:MUST> be located at the top (first
                  position) of the queue.

                = Invoke the algorithm recursively.

             }

             {LI:: If the node is <C::NodeFilter.MANAKAI_FILTER_OPAQUE>,
 
                = Prepend the node to the queue, with
                  phase value set to <C::SerialWalker.POST_PHASE>.

                = Prepend the node to the queue, with
                  phase value set to <C::SerialWalker.PRE_PHASE>.
               
                = If the node has a previous sibling in the logical view,
                  preprend the parent node of the node in the logical
                  view, with phase value set to <C::SerialWalker.IN_PHASE>.

                = Invoke the algorithm recursively.

             }

             - Otherwise, invoke the algorithm recursively.

          }
       }

    }

    {NOTE::
      This algorithm will stop unless nodes are simulataneously
      populated to the underlying tree by application via
      e.g. <IF::NodeFilter>.
    }

    Implementation <kwd:MAY> choose to implement the <IF::SerialWalker>
    using another algorithm.  In particular, when the <IF::NodeFilter>
    is invoked might vary across implementations.  Implementations
    should try to return the same effect as the reference algorithm
    even if the underlying subtree is modified, but applications
    <kwd:MUST-NOT> rely on the particular implementation's behavior.

    As long as the underlying subtree is not modified, a node will
    never set to the <A::SerialWalker.currentNode> attribute
    with the <A::SerialWalker.currentPhase> of <C::SerialWalker.PRE_PHASE>.
    If the underlying subtree is modified, depending on how
    the method is implemented, it might be in case.  For 
    the purpose of description below, such duplication was considered
    as if they were different nodes.

    {P:: Even if the underlying subtree has been modified during
         the traversal, the implementation <kwd:MUST> ensure
         the following conditions are met:

      - A node <kwd:MUST-NOT> be set to the <A::SerialWalker.currentNode>
        attribute with the <A::SerialWalker.currentPhase> of
        <C::SerialWalker.PRE_PHASE> or <C::SerialWalker.POST_PHASE>
        more than once respectively.

      - A node <kwd:MUST-NOT> be set to the <A::SerialWalker.currentNode>
        attribute with the <A::SerialWalker.currentPhase> of
        <C::SerialWalker.IN_PHASE> before it is once set to
        the same node with the <A::SerialWalker.currentPhase>
        of <C::SerialWalker.PRE_PHASE>, or after it is once set
        to the same node with the <A::SerialWalker.currentPhase>
        of <C::SerialWalker.POST_PHASE>.

      - A node <kwd:MUST-NOT> be set to the <A::SerialWalker.currentNode>
        attribute with the <A::SerialWalker.currentPhase> of
        <C::SerialWalker.POST_PHASE> before it is once set to
        the same node with the <A::SerialWalker.currentPhase>
        of <C::SerialWalker.PRE_PHASE>.

      - A node <kwd:MUST> be set to the <A::SerialWalker.currentNode>
        attribute with the <A::SerialWalker.currentPhase> of
        <C::SerialWalker.POST_PHASE> later if it is once set to
        the same node with the <A::SerialWalker.currentPhase>
        of <C::SerialWalker.PRE_PHASE>.

      - The <A::SerialWalker.currentPhase> <kwd:MUST-NOT> set
        to <C::SerialWalker.PRE_PHASE> unless its value is
        <C::SerialWalker.PRE_PHASE> or <C::SerialWalker.IN_PHASE>.

      - The <A::SerialWalker.currentPhase> <kwd:MUST-NOT> set
        to <C::SerialWalker.IN_PHASE> unless its value is
        <C::SerialWalker.POST_PHASE>.

      - The <A::SerialWalker.currentPhase> <kwd:MUST-NOT> set
        to <C::SerialWalker.POST_PHASE> unless its value is
        <C::SerialWalker.PRE_PHASE> or <C::SerialWalker.POST_PHASE>.

      - If a node <VAR::N> is set to the <A::SerialWalker.currentNode>
        attribute and then another node <VAR::M> is set to the attribute
        with both <A::SerialWalker.currentPhase> of <C::SerialWalker.PRE_PHASE>,
        the <A::SerialWalker.currentNode> attribute <kwd:MUST-NOT> be set to
        <VAR::N> with <A::SerialWalker.currentPhase> of
        <C::SerialWalker.POST_PHASE> before once the
        <A::SerialWalker.currentNode> attribute is set to
        <VAR::M> with <A::SerialWalker.currentPhase> of 
        <C::SerialWalker.POST_PHASE>.

      - For each time the <A::SerialWalker.currentNode> attribute is
        set to a node, the <A::SerialWalker.currentIndex> <kwd:MUST>
        be increased by one.  If the node is set to the attribute
        for the first time, the <A::SerialWalker.currentIndex> 
        <kwd:MUST> be set to zero.  That is, with and only with
        <C::SerialWalker.PRE_PHASE> the <A::SerialWalker.currentIndex>
        can be zero.
    }

  @CODE:
    @@QName: createSWForTest
    @@PerlDef:
      __CODE{tc|createEmptyDocumentForTest:: $doc => $doc}__;

      my $docel = $doc-><M::Document.createElement> ('docel');

      $doc-><M::Node.appendChild> ($docel);

      my $doctrv = $doc-><M::Node.getFeature> ('Traversal', '2.0');
      $sw = $doctrv-><M::DocumentTraversal.manakaiCreateSerialWalker> ($docel);

  @LXAttr:
    @@Name: root
    @@enDesc:
      The root node of the <IF::SerialWalker>.
    @@Type: Node
    @@Get:
      @@@enDesc:
        The root node set when the <IF::SerialWalker> is created.
      @@@PerlDef:
        $r = $self->{root};

  @LXAttr:
    @@Name: currentNode
    @@enDesc:
      The current node of the <IF::SerialWalker>.

        {NOTE::
          Unlike <IF::TreeWalker>, the <A::SerialWalker.currentNode>
          attribute is read-only.
        }
    @@Type: Node
    @@Get:
      @@@enDesc:
        The current node.
      @@@PerlDef:
        $r = $self->{current_node};

  @mShortConstGroup:
    @@IFQName: SerialWalkerPhase
    @@enDesc:
      An integer to indicate a phase of <IF::SerialWalker>.

    @@mConst:
      @@@Name: PRE_PHASE
      @@@intValue: 1
      @@@enDesc:
        The <A::SerialWalker.currentNode> is visited by
        the <IF::SerialWalker> for the first time.  It is
        expected that the same node will be revisited
        with <A::SerialWalker.currentPhase> of 
        <C::SerialWalker.IN_PHASE> (optionally) and
        <C::SerialWalker.POST_PHASE> later.
    @@mConst:
      @@@Name: IN_PHASE
      @@@intValue: 2
      @@@enDesc:
        The <A::SerialWalker.currentNode> is visited
        by the <IF::SerialWalker>, not for the first
        or last time, between visitings to its two child nodes.
    @@mConst:
      @@@Name: POST_PHASE
      @@@intValue: 3
      @@@enDesc:
        The <A::SerialWalker.currentNode> is visited
        by the <IF::SerialWalker> for the last time.

  @LXAttr:
    @@Name: currentPhase
    @@enDesc:
      The current phase of the <IF::SerialWalker>.
    @@Type: unsignedShort
    @@actualType: SerialWalkerPhase
    @@Get:
      @@@enDesc:
        An integer to indicate the current phase.
      @@@PerlDef:
        $r = $self->{current_phase};

  @LXAttr:
    @@Name: currentIndex
    @@enDesc:
      The current index of the <IF::SerialWalker>.  The 
      <DFN::current index> represents how many times the
      <A::SerialWalker.currentNode> is exposed through
      the <IF::SerialWalker>.
    @@Type: unsignedLong
    @@Get:
      @@@enDesc:
        An integer to indicate the current index.
      @@@PerlDef:
        $r = $self->{current_index};

  @LXAttr:
    @@Name: expandEntityReferences
    @@enDesc:
      The value of the flag that determines whether the children of
      <IF::tx|EntityReference> nodes are visible to the <IF::SerialWalker>.

      {NOTE::
        To produce a view of the document that has entity references
        expanded and does not expose the <IF::tx|EntityReference> nodes
        themselves, use the <A::SerialWalker.whatToShow> flags to hide the
        <IF::tx|EntityReference> nodes and set the
        <A::SerialWalker.expandEntityReferences> flag to <DOM::true>
        when creating the <IF::SerialWalker>.

        To produce a view of the document that has <IF::tx|EntityReference>
        nodes but no entity expansion, use the <A::SerialWalker.whatToShow>
        flags to show the <IF::tx|EntityReference> nodes and set the
        <A::SerialWalker.expandEntityReferences> flag to <DOM::false>
        when creating the <IF::SerialWalker>.
      }
    @@Type: boolean
    @@Get:
      @@@enDesc:
        The <CODE::entityReferenceExpansion> value that
        was specified when the <IF::SerialWalker> was created.
      @@@TrueCase:
        @@@@enDesc:
          The children and their descendants of <IF::tx|EntityReference>
          nodes will <EM::not> be rejected.  Note that
          the <A::SerialWalker.whatToShow> flags and the
          <A::SerialWalker.filter> set to the <IF::SerialWalker>
          might reject them as usual way.
      @@@FalseCase:
        @@@@enDesc:
          The children and their descendants of entity reference nodes
          will be rejected.  This rejection takes precedence over
          the <A::SerialWalker.whatToShow> flags and the
          <A::SerialWalker.filter> set to the 
          <IF::SerialWalker>, if any.
      @@@PerlDef:
        $r = $self->{expand_entity_references};

  @LXAttr:
    @@Name: filter
    @@enDesc:
      The filter used to screen nodes.
    @@Type: NodeFilter
    @@Get:
      @@@enDesc:
        The <IF::NodeFilter> that was specified when the
        <IF::SerialWalker> was created.
      @@@nullCase:
        @@@@enDesc:
          If no <IF::NodeFilter> was specified when the
          <IF::SerialWalker> was created.
      @@@PerlDef:
        $r = $self->{filter};

  @LXAttr:
    @@Name: whatToShow
    @@enDesc:
      The flags that determines which node types are presented
      via the <IF::SerialWalker>.  The available set of constants
      is defined in the <IF::NodeFilter> interface.

      Nodes not accepted by the <A::SerialWalker.whatToShow>
      flags will be skipped, but their children may still be
      considered.  This skip takes precedence over the 
      <A::SerialWalker.filter> set to the <IF::SerialWalker>, if any.
    @@Type: unsignedShort
    @@actualType: WhatToShow
    @@Get:
      @@@enDesc:
        The <CODE::whatToShow> value that was specified
        when the <IF::SerialWalker> was created.
      @@@PerlDef:
        $r = $self->{what_to_show};

  @LXMethod:
    @@Name: nextNode
    @@enDesc:
      Returns the node next to the <A::SerialWalker.currentNode>
      of the <IF::SerialWalker>.
    @@Return:
      @@@Type: Node
      @@@enDesc:
        The next node.
      @@@nullCase:
        @@@@enDesc:
          If no next node.
1	wakaba	1.1	@@ WIP
2
3			IFClsXDef:
4			@IFQName: SerialWalker
5			@ClsQName: ManakaiDOMSerialWalker
6
7			@enDesc:
8			{ISSUE::
9			Better name?
10			}
11
12			A <IF::SerialWalker> object can be used to traverse
13			the subtree rooted by a node in document order.
14			Unlike <IF::TreeWalker> and <IF::NodeIterator>, the
15			<IF::SerialWalker> object cannot go back toward
16			nodes that had already been seen. The
17			<IF::SerialWalker>, however, revisits a node after its
18			children are visited. This might be useful when
19			an application wants to serialize a subtree in a format
20			where delimiter and / or terminator should be inserted
21			between and / or after nodes.
22
23			How the <IF::SerialWalker> works is defined by the following
24			reference algorithm. An implementation does not have to
25			implement this exact algorithm, but it <kwd:MUST> implement
26			its method so that it has the same effect as the
27			reference algorithm when the underlying subtree has not
28			been modified.
29
30			At the time of creation of the <IF::SerialWalker>,
31			the implementation <kwd:MUST> prepare a queue and
32			<kwd:MUST> initialize it by pushing the <A::SerialWalker.root> node.
33
34			{P:: When the <M::SerialWalker.nextNode> method is invoked,
35
36			- If the queue is empty, the method <kwd:MUST> return
37			<DOM::null>. It <kwd:MUST-NOT> change
38			<A::SerialWalker.currentNode>, <A::SerialWalker.currentPhase>,
39			and <A::SerialWalker.currentIndex> attributes.
40
41			{LI:: Otherwise,
42
43			- Shift a node from the queue. If the node has
44			the phase value, the method <kwd:MUST> return
45			the node. In addition, it <kwd:MUST> set
46			the <A::SerialWalker.currentNode> attribute to the node,
47			the <A::SerialWalker.currentPhase> attribute to
48			the associated phase value, and the
49			<A::SerialWalker.currentIndex> attribute to
50			the integer value that is large by one than
51			the most recent <A::SerialWalker.currentIndex> value
52			when the <A::SerialWalker.currentNode> was
53			same as the shiftted node. If it is the first time
54			the node is set to the <A::SerialWalker.currentNode>
55			attribute, the <A::SerialWalker.currentIndex>
56			attribute <kwd:MUST> set to zero.
57
58			{LI:: Otherwise, determine whether the shifted node
59			should be accepted or not, using
60			<A::SerialWalker.expandEntityReferences>,
61			<A::SerialWalker.whatToShow>, and
62			<A::SerialWalker.filter> attributes, as defined
63			for the <IF::TreeWalker> interface.
64
65			{LI:: If the node is <C::NodeFilter.FILTER_ACCEPT>ed,
66
67			= Prepend the node to the queue, with
68			phase value set to <C::SerialWalker.POST_PHASE>.
69
70			= Prepend the child nodes of the node, if any,
71			to the queue keeping the document order,
72			without phase value. That is, the first child
73			<kwd:MUST> be located at the top (first
74			position) of the queue.
75
76			= Prepend the node to the queue, with
77			phase value set to <C::SerialWalker.PRE_PHASE>.
78
79			= If the node has a previous sibling in the logical view,
80			preprend the parent node of the node in the logical
81			view, with phase value set to <C::SerialWalker.IN_PHASE>.
82
83			= Invoke the algorithm recursively.
84
85			}
86
87			{LI:: If the node is <C::NodeFilter.FILTER_SKIP>ped,
88
89			= Prepend the child nodes of the node, if any,
90			to the queue keeping the document order,
91			without phase value. That is, the first child
92			<kwd:MUST> be located at the top (first
93			position) of the queue.
94
95			= Invoke the algorithm recursively.
96
97			}
98
99			{LI:: If the node is <C::NodeFilter.MANAKAI_FILTER_OPAQUE>,
100
101			= Prepend the node to the queue, with
102			phase value set to <C::SerialWalker.POST_PHASE>.
103
104			= Prepend the node to the queue, with
105			phase value set to <C::SerialWalker.PRE_PHASE>.
106
107			= If the node has a previous sibling in the logical view,
108			preprend the parent node of the node in the logical
109			view, with phase value set to <C::SerialWalker.IN_PHASE>.
110
111			= Invoke the algorithm recursively.
112
113			}
114
115			- Otherwise, invoke the algorithm recursively.
116
117			}
118			}
119
120			}
121
122			{NOTE::
123			This algorithm will stop unless nodes are simulataneously
124			populated to the underlying tree by application via
125			e.g. <IF::NodeFilter>.
126			}
127
128			Implementation <kwd:MAY> choose to implement the <IF::SerialWalker>
129			using another algorithm. In particular, when the <IF::NodeFilter>
130			is invoked might vary across implementations. Implementations
131			should try to return the same effect as the reference algorithm
132			even if the underlying subtree is modified, but applications
133			<kwd:MUST-NOT> rely on the particular implementation's behavior.
134
135			As long as the underlying subtree is not modified, a node will
136			never set to the <A::SerialWalker.currentNode> attribute
137			with the <A::SerialWalker.currentPhase> of <C::SerialWalker.PRE_PHASE>.
138			If the underlying subtree is modified, depending on how
139			the method is implemented, it might be in case. For
140			the purpose of description below, such duplication was considered
141			as if they were different nodes.
142
143			{P:: Even if the underlying subtree has been modified during
144			the traversal, the implementation <kwd:MUST> ensure
145			the following conditions are met:
146
147			- A node <kwd:MUST-NOT> be set to the <A::SerialWalker.currentNode>
148			attribute with the <A::SerialWalker.currentPhase> of
149			<C::SerialWalker.PRE_PHASE> or <C::SerialWalker.POST_PHASE>
150			more than once respectively.
151
152			- A node <kwd:MUST-NOT> be set to the <A::SerialWalker.currentNode>
153			attribute with the <A::SerialWalker.currentPhase> of
154			<C::SerialWalker.IN_PHASE> before it is once set to
155			the same node with the <A::SerialWalker.currentPhase>
156			of <C::SerialWalker.PRE_PHASE>, or after it is once set
157			to the same node with the <A::SerialWalker.currentPhase>
158			of <C::SerialWalker.POST_PHASE>.
159
160			- A node <kwd:MUST-NOT> be set to the <A::SerialWalker.currentNode>
161			attribute with the <A::SerialWalker.currentPhase> of
162			<C::SerialWalker.POST_PHASE> before it is once set to
163			the same node with the <A::SerialWalker.currentPhase>
164			of <C::SerialWalker.PRE_PHASE>.
165
166			- A node <kwd:MUST> be set to the <A::SerialWalker.currentNode>
167			attribute with the <A::SerialWalker.currentPhase> of
168			<C::SerialWalker.POST_PHASE> later if it is once set to
169			the same node with the <A::SerialWalker.currentPhase>
170			of <C::SerialWalker.PRE_PHASE>.
171
172			- The <A::SerialWalker.currentPhase> <kwd:MUST-NOT> set
173			to <C::SerialWalker.PRE_PHASE> unless its value is
174			<C::SerialWalker.PRE_PHASE> or <C::SerialWalker.IN_PHASE>.
175
176			- The <A::SerialWalker.currentPhase> <kwd:MUST-NOT> set
177			to <C::SerialWalker.IN_PHASE> unless its value is
178			<C::SerialWalker.POST_PHASE>.
179
180			- The <A::SerialWalker.currentPhase> <kwd:MUST-NOT> set
181			to <C::SerialWalker.POST_PHASE> unless its value is
182			<C::SerialWalker.PRE_PHASE> or <C::SerialWalker.POST_PHASE>.
183
184			- If a node <VAR::N> is set to the <A::SerialWalker.currentNode>
185			attribute and then another node <VAR::M> is set to the attribute
186			with both <A::SerialWalker.currentPhase> of <C::SerialWalker.PRE_PHASE>,
187			the <A::SerialWalker.currentNode> attribute <kwd:MUST-NOT> be set to
188			<VAR::N> with <A::SerialWalker.currentPhase> of
189			<C::SerialWalker.POST_PHASE> before once the
190			<A::SerialWalker.currentNode> attribute is set to
191			<VAR::M> with <A::SerialWalker.currentPhase> of
192			<C::SerialWalker.POST_PHASE>.
193
194			- For each time the <A::SerialWalker.currentNode> attribute is
195			set to a node, the <A::SerialWalker.currentIndex> <kwd:MUST>
196			be increased by one. If the node is set to the attribute
197			for the first time, the <A::SerialWalker.currentIndex>
198			<kwd:MUST> be set to zero. That is, with and only with
199			<C::SerialWalker.PRE_PHASE> the <A::SerialWalker.currentIndex>
200			can be zero.
201			}
202
203			@CODE:
204			@@QName: createSWForTest
205			@@PerlDef:
206			__CODE{tc\|createEmptyDocumentForTest:: $doc => $doc}__;
207
208			my $docel = $doc-><M::Document.createElement> ('docel');
209
210			$doc-><M::Node.appendChild> ($docel);
211
212			my $doctrv = $doc-><M::Node.getFeature> ('Traversal', '2.0');
213			$sw = $doctrv-><M::DocumentTraversal.manakaiCreateSerialWalker> ($docel);
214
215			@LXAttr:
216			@@Name: root
217			@@enDesc:
218			The root node of the <IF::SerialWalker>.
219			@@Type: Node
220			@@Get:
221			@@@enDesc:
222			The root node set when the <IF::SerialWalker> is created.
223			@@@PerlDef:
224			$r = $self->{root};
225
226			@LXAttr:
227			@@Name: currentNode
228			@@enDesc:
229			The current node of the <IF::SerialWalker>.
230
231			{NOTE::
232			Unlike <IF::TreeWalker>, the <A::SerialWalker.currentNode>
233			attribute is read-only.
234			}
235			@@Type: Node
236			@@Get:
237			@@@enDesc:
238			The current node.
239			@@@PerlDef:
240			$r = $self->{current_node};
241
242			@mShortConstGroup:
243			@@IFQName: SerialWalkerPhase
244			@@enDesc:
245			An integer to indicate a phase of <IF::SerialWalker>.
246
247			@@mConst:
248			@@@Name: PRE_PHASE
249			@@@intValue: 1
250			@@@enDesc:
251			The <A::SerialWalker.currentNode> is visited by
252			the <IF::SerialWalker> for the first time. It is
253			expected that the same node will be revisited
254			with <A::SerialWalker.currentPhase> of
255			<C::SerialWalker.IN_PHASE> (optionally) and
256			<C::SerialWalker.POST_PHASE> later.
257			@@mConst:
258			@@@Name: IN_PHASE
259			@@@intValue: 2
260			@@@enDesc:
261			The <A::SerialWalker.currentNode> is visited
262			by the <IF::SerialWalker>, not for the first
263			or last time, between visitings to its two child nodes.
264			@@mConst:
265			@@@Name: POST_PHASE
266			@@@intValue: 3
267			@@@enDesc:
268			The <A::SerialWalker.currentNode> is visited
269			by the <IF::SerialWalker> for the last time.
270
271			@LXAttr:
272			@@Name: currentPhase
273			@@enDesc:
274			The current phase of the <IF::SerialWalker>.
275			@@Type: unsignedShort
276			@@actualType: SerialWalkerPhase
277			@@Get:
278			@@@enDesc:
279			An integer to indicate the current phase.
280			@@@PerlDef:
281			$r = $self->{current_phase};
282
283			@LXAttr:
284			@@Name: currentIndex
285			@@enDesc:
286			The current index of the <IF::SerialWalker>. The
287			<DFN::current index> represents how many times the
288			<A::SerialWalker.currentNode> is exposed through
289			the <IF::SerialWalker>.
290			@@Type: unsignedLong
291			@@Get:
292			@@@enDesc:
293			An integer to indicate the current index.
294			@@@PerlDef:
295			$r = $self->{current_index};
296
297			@LXAttr:
298			@@Name: expandEntityReferences
299			@@enDesc:
300			The value of the flag that determines whether the children of
301			<IF::tx\|EntityReference> nodes are visible to the <IF::SerialWalker>.
302
303			{NOTE::
304			To produce a view of the document that has entity references
305			expanded and does not expose the <IF::tx\|EntityReference> nodes
306			themselves, use the <A::SerialWalker.whatToShow> flags to hide the
307			<IF::tx\|EntityReference> nodes and set the
308			<A::SerialWalker.expandEntityReferences> flag to <DOM::true>
309			when creating the <IF::SerialWalker>.
310
311			To produce a view of the document that has <IF::tx\|EntityReference>
312			nodes but no entity expansion, use the <A::SerialWalker.whatToShow>
313			flags to show the <IF::tx\|EntityReference> nodes and set the
314			<A::SerialWalker.expandEntityReferences> flag to <DOM::false>
315			when creating the <IF::SerialWalker>.
316			}
317			@@Type: boolean
318			@@Get:
319			@@@enDesc:
320			The <CODE::entityReferenceExpansion> value that
321			was specified when the <IF::SerialWalker> was created.
322			@@@TrueCase:
323			@@@@enDesc:
324			The children and their descendants of <IF::tx\|EntityReference>
325			nodes will <EM::not> be rejected. Note that
326			the <A::SerialWalker.whatToShow> flags and the
327			<A::SerialWalker.filter> set to the <IF::SerialWalker>
328			might reject them as usual way.
329			@@@FalseCase:
330			@@@@enDesc:
331			The children and their descendants of entity reference nodes
332			will be rejected. This rejection takes precedence over
333			the <A::SerialWalker.whatToShow> flags and the
334			<A::SerialWalker.filter> set to the
335			<IF::SerialWalker>, if any.
336			@@@PerlDef:
337			$r = $self->{expand_entity_references};
338
339			@LXAttr:
340			@@Name: filter
341			@@enDesc:
342			The filter used to screen nodes.
343			@@Type: NodeFilter
344			@@Get:
345			@@@enDesc:
346			The <IF::NodeFilter> that was specified when the
347			<IF::SerialWalker> was created.
348			@@@nullCase:
349			@@@@enDesc:
350			If no <IF::NodeFilter> was specified when the
351			<IF::SerialWalker> was created.
352			@@@PerlDef:
353			$r = $self->{filter};
354
355			@LXAttr:
356			@@Name: whatToShow
357			@@enDesc:
358			The flags that determines which node types are presented
359			via the <IF::SerialWalker>. The available set of constants
360			is defined in the <IF::NodeFilter> interface.
361
362			Nodes not accepted by the <A::SerialWalker.whatToShow>
363			flags will be skipped, but their children may still be
364			considered. This skip takes precedence over the
365			<A::SerialWalker.filter> set to the <IF::SerialWalker>, if any.
366			@@Type: unsignedShort
367			@@actualType: WhatToShow
368			@@Get:
369			@@@enDesc:
370			The <CODE::whatToShow> value that was specified
371			when the <IF::SerialWalker> was created.
372			@@@PerlDef:
373			$r = $self->{what_to_show};
374
375			@LXMethod:
376			@@Name: nextNode
377			@@enDesc:
378			Returns the node next to the <A::SerialWalker.currentNode>
379			of the <IF::SerialWalker>.
380			@@Return:
381			@@@Type: Node
382			@@@enDesc:
383			The next node.
384			@@@nullCase:
385			@@@@enDesc:
386			If no next node.