/*
* [The "BSD licence"]
* Copyright (c) 2011 Terence Parr
* All rights reserved.
*
* Conversion to C#:
* Copyright (c) 2011 Sam Harwell, Pixel Mine, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
namespace Antlr.Runtime.Tree
{
/** <summary>
* How to create and navigate trees. Rather than have a separate factory
* and adaptor, I've merged them. Makes sense to encapsulate.
* </summary>
*
* <remarks>
* This takes the place of the tree construction code generated in the
* generated code in 2.x and the ASTFactory.
*
* I do not need to know the type of a tree at all so they are all
* generic Objects. This may increase the amount of typecasting needed. :(
* </remarks>
*/
public interface ITreeAdaptor
{
#region Construction
/** <summary>
* Create a tree node from Token object; for CommonTree type trees,
* then the token just becomes the payload. This is the most
* common create call.
* </summary>
*
* <remarks>
* Override if you want another kind of node to be built.
* </remarks>
*/
object Create(IToken payload);
/** <summary>
* Create a new node derived from a token, with a new token type.
* This is invoked from an imaginary node ref on right side of a
* rewrite rule as IMAG[$tokenLabel].
* </summary>
*
* <remarks>
* This should invoke createToken(Token).
* </remarks>
*/
object Create(int tokenType, IToken fromToken);
/** <summary>
* Same as create(tokenType,fromToken) except set the text too.
* This is invoked from an imaginary node ref on right side of a
* rewrite rule as IMAG[$tokenLabel, "IMAG"].
* </summary>
*
* <remarks>
* This should invoke createToken(Token).
* </remarks>
*/
object Create(int tokenType, IToken fromToken, string text);
/** <summary>
* Same as create(fromToken) except set the text too.
* This is invoked when the <c>text</c> terminal option is set, as in
* IMAG<text='IMAG'>.
* </summary>
*
* <remarks>
* This should invoke createToken(Token).
* </remarks>
*/
object Create(IToken fromToken, string text);
/** <summary>
* Create a new node derived from a token, with a new token type.
* This is invoked from an imaginary node ref on right side of a
* rewrite rule as IMAG["IMAG"].
* </summary>
*
* <remarks>
* This should invoke createToken(int,String).
* </remarks>
*/
object Create(int tokenType, string text);
/** <summary>Duplicate a single tree node.</summary>
* <remarks>Override if you want another kind of node to be built.</remarks>
*/
object DupNode(object treeNode);
object DupNode(int type, object treeNode);
object DupNode(object treeNode, string text);
object DupNode(int type, object treeNode, string text);
/** <summary>Duplicate tree recursively, using dupNode() for each node</summary> */
object DupTree( object tree );
/** <summary>
* Return a nil node (an empty but non-null node) that can hold
* a list of element as the children. If you want a flat tree (a list)
* use "t=adaptor.nil(); t.addChild(x); t.addChild(y);"
* </summary>
*/
object Nil();
/** <summary>
* Return a tree node representing an error. This node records the
* tokens consumed during error recovery. The start token indicates the
* input symbol at which the error was detected. The stop token indicates
* the last symbol consumed during recovery.
* </summary>
*
* </remarks>
* You must specify the input stream so that the erroneous text can
* be packaged up in the error node. The exception could be useful
* to some applications; default implementation stores ptr to it in
* the CommonErrorNode.
*
* This only makes sense during token parsing, not tree parsing.
* Tree parsing should happen only when parsing and tree construction
* succeed.
* </remarks>
*/
object ErrorNode( ITokenStream input, IToken start, IToken stop, RecognitionException e );
/** <summary>Is tree considered a nil node used to make lists of child nodes?</summary> */
bool IsNil( object tree );
/** <summary>
* Add a child to the tree t. If child is a flat tree (a list), make all
* in list children of t. Warning: if t has no children, but child does
* and child isNil then you can decide it is ok to move children to t via
* t.children = child.children; i.e., without copying the array. Just
* make sure that this is consistent with have the user will build
* ASTs. Do nothing if t or child is null.
* </summary>
*/
void AddChild( object t, object child );
/** <summary>
* If oldRoot is a nil root, just copy or move the children to newRoot.
* If not a nil root, make oldRoot a child of newRoot.
* </summary>
*
* <remarks>
* old=^(nil a b c), new=r yields ^(r a b c)
* old=^(a b c), new=r yields ^(r ^(a b c))
*
* If newRoot is a nil-rooted single child tree, use the single
* child as the new root node.
*
* old=^(nil a b c), new=^(nil r) yields ^(r a b c)
* old=^(a b c), new=^(nil r) yields ^(r ^(a b c))
*
* If oldRoot was null, it's ok, just return newRoot (even if isNil).
*
* old=null, new=r yields r
* old=null, new=^(nil r) yields ^(nil r)
*
* Return newRoot. Throw an exception if newRoot is not a
* simple node or nil root with a single child node--it must be a root
* node. If newRoot is ^(nil x) return x as newRoot.
*
* Be advised that it's ok for newRoot to point at oldRoot's
* children; i.e., you don't have to copy the list. We are
* constructing these nodes so we should have this control for
* efficiency.
* </remarks>
*/
object BecomeRoot( object newRoot, object oldRoot );
/** <summary>
* Given the root of the subtree created for this rule, post process
* it to do any simplifications or whatever you want. A required
* behavior is to convert ^(nil singleSubtree) to singleSubtree
* as the setting of start/stop indexes relies on a single non-nil root
* for non-flat trees.
* </summary>
*
* <remarks>
* Flat trees such as for lists like "idlist : ID+ ;" are left alone
* unless there is only one ID. For a list, the start/stop indexes
* are set in the nil node.
*
* This method is executed after all rule tree construction and right
* before setTokenBoundaries().
* </remarks>
*/
object RulePostProcessing( object root );
/** <summary>For identifying trees.</summary>
*
* <remarks>
* How to identify nodes so we can say "add node to a prior node"?
* Even becomeRoot is an issue. Use System.identityHashCode(node)
* usually.
* </remarks>
*/
int GetUniqueID( object node );
// R e w r i t e R u l e s
/** <summary>
* Create a node for newRoot make it the root of oldRoot.
* If oldRoot is a nil root, just copy or move the children to newRoot.
* If not a nil root, make oldRoot a child of newRoot.
* </summary>
*
* <returns>
* Return node created for newRoot.
* </returns>
*
* <remarks>
* Be advised: when debugging ASTs, the DebugTreeAdaptor manually
* calls create(Token child) and then plain becomeRoot(node, node)
* because it needs to trap calls to create, but it can't since it delegates
* to not inherits from the TreeAdaptor.
* </remarks>
*/
object BecomeRoot( IToken newRoot, object oldRoot );
#endregion
#region Content
/** <summary>For tree parsing, I need to know the token type of a node</summary> */
int GetType( object t );
/** <summary>Node constructors can set the type of a node</summary> */
void SetType( object t, int type );
string GetText( object t );
/** <summary>Node constructors can set the text of a node</summary> */
void SetText( object t, string text );
/** <summary>
* Return the token object from which this node was created.
* Currently used only for printing an error message.
* The error display routine in BaseRecognizer needs to
* display where the input the error occurred. If your
* tree of limitation does not store information that can
* lead you to the token, you can create a token filled with
* the appropriate information and pass that back. See
* BaseRecognizer.getErrorMessage().
* </summary>
*/
IToken GetToken( object t );
/** <summary>
* Where are the bounds in the input token stream for this node and
* all children? Each rule that creates AST nodes will call this
* method right before returning. Flat trees (i.e., lists) will
* still usually have a nil root node just to hold the children list.
* That node would contain the start/stop indexes then.
* </summary>
*/
void SetTokenBoundaries( object t, IToken startToken, IToken stopToken );
/** <summary>Get the token start index for this subtree; return -1 if no such index</summary> */
int GetTokenStartIndex( object t );
/** <summary>Get the token stop index for this subtree; return -1 if no such index</summary> */
int GetTokenStopIndex( object t );
#endregion
#region Navigation / Tree Parsing
/** <summary>Get a child 0..n-1 node</summary> */
object GetChild( object t, int i );
/** <summary>Set ith child (0..n-1) to t; t must be non-null and non-nil node</summary> */
void SetChild( object t, int i, object child );
/** <summary>Remove ith child and shift children down from right.</summary> */
object DeleteChild( object t, int i );
/** <summary>How many children? If 0, then this is a leaf node</summary> */
int GetChildCount( object t );
/** <summary>
* Who is the parent node of this node; if null, implies node is root.
* If your node type doesn't handle this, it's ok but the tree rewrites
* in tree parsers need this functionality.
* </summary>
*/
object GetParent( object t );
void SetParent( object t, object parent );
/** <summary>
* What index is this node in the child list? Range: 0..n-1
* If your node type doesn't handle this, it's ok but the tree rewrites
* in tree parsers need this functionality.
* </summary>
*/
int GetChildIndex( object t );
void SetChildIndex( object t, int index );
/** <summary>
* Replace from start to stop child index of parent with t, which might
* be a list. Number of children may be different after this call.
* </summary>
*
* <remarks>
* If parent is null, don't do anything; must be at root of overall tree.
* Can't replace whatever points to the parent externally. Do nothing.
* </remarks>
*/
void ReplaceChildren( object parent, int startChildIndex, int stopChildIndex, object t );
#endregion
}
}