diff options
Diffstat (limited to 'runtime/CSharp3/Sources/Antlr3.Runtime/Tree/RewriteRuleElementStream.cs')
| -rw-r--r-- | runtime/CSharp3/Sources/Antlr3.Runtime/Tree/RewriteRuleElementStream.cs | 253 |
1 files changed, 0 insertions, 253 deletions
diff --git a/runtime/CSharp3/Sources/Antlr3.Runtime/Tree/RewriteRuleElementStream.cs b/runtime/CSharp3/Sources/Antlr3.Runtime/Tree/RewriteRuleElementStream.cs deleted file mode 100644 index cb76ace..0000000 --- a/runtime/CSharp3/Sources/Antlr3.Runtime/Tree/RewriteRuleElementStream.cs +++ /dev/null @@ -1,253 +0,0 @@ -/* - * [The "BSD licence"] - * Copyright (c) 2005-2008 Terence Parr - * All rights reserved. - * - * Conversion to C#: - * Copyright (c) 2008-2009 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 -{ - using System.Collections.Generic; - using IList = System.Collections.IList; - - /** <summary> - * A generic list of elements tracked in an alternative to be used in - * a -> rewrite rule. We need to subclass to fill in the next() method, - * which returns either an AST node wrapped around a token payload or - * an existing subtree. - * </summary> - * - * <remarks> - * Once you start next()ing, do not try to add more elements. It will - * break the cursor tracking I believe. - * - * TODO: add mechanism to detect/puke on modification after reading from stream - * </remarks> - * - * <see cref="RewriteRuleSubtreeStream"/> - * <see cref="RewriteRuleTokenStream"/> - */ - [System.Serializable] - public abstract class RewriteRuleElementStream - { - /** <summary> - * Cursor 0..n-1. If singleElement!=null, cursor is 0 until you next(), - * which bumps it to 1 meaning no more elements. - * </summary> - */ - protected int cursor = 0; - - /** <summary>Track single elements w/o creating a list. Upon 2nd add, alloc list */ - protected object singleElement; - - /** <summary>The list of tokens or subtrees we are tracking */ - protected IList elements; - - /** <summary>Once a node / subtree has been used in a stream, it must be dup'd - * from then on. Streams are reset after subrules so that the streams - * can be reused in future subrules. So, reset must set a dirty bit. - * If dirty, then next() always returns a dup.</summary> - */ - protected bool dirty = false; - - /** <summary>The element or stream description; usually has name of the token or - * rule reference that this list tracks. Can include rulename too, but - * the exception would track that info. - */ - protected string elementDescription; - protected ITreeAdaptor adaptor; - - public RewriteRuleElementStream( ITreeAdaptor adaptor, string elementDescription ) - { - this.elementDescription = elementDescription; - this.adaptor = adaptor; - } - - /** <summary>Create a stream with one element</summary> */ - public RewriteRuleElementStream( ITreeAdaptor adaptor, string elementDescription, object oneElement ) - : this( adaptor, elementDescription ) - { - Add( oneElement ); - } - - /** <summary>Create a stream, but feed off an existing list</summary> */ - public RewriteRuleElementStream( ITreeAdaptor adaptor, string elementDescription, IList elements ) - : this( adaptor, elementDescription ) - { - this.singleElement = null; - this.elements = elements; - } - - /** <summary> - * Reset the condition of this stream so that it appears we have - * not consumed any of its elements. Elements themselves are untouched. - * Once we reset the stream, any future use will need duplicates. Set - * the dirty bit. - * </summary> - */ - public virtual void Reset() - { - cursor = 0; - dirty = true; - } - - public virtual void Add( object el ) - { - //System.out.println("add '"+elementDescription+"' is "+el); - if ( el == null ) - { - return; - } - if ( elements != null ) - { // if in list, just add - elements.Add( el ); - return; - } - if ( singleElement == null ) - { // no elements yet, track w/o list - singleElement = el; - return; - } - // adding 2nd element, move to list - elements = new List<object>( 5 ); - elements.Add( singleElement ); - singleElement = null; - elements.Add( el ); - } - - /** <summary> - * Return the next element in the stream. If out of elements, throw - * an exception unless size()==1. If size is 1, then return elements[0]. - * Return a duplicate node/subtree if stream is out of elements and - * size==1. If we've already used the element, dup (dirty bit set). - * </summary> - */ - public virtual object NextTree() - { - int n = Count; - if ( dirty || ( cursor >= n && n == 1 ) ) - { - // if out of elements and size is 1, dup - object el = NextCore(); - return Dup( el ); - } - // test size above then fetch - object el2 = NextCore(); - return el2; - } - - /** <summary> - * Do the work of getting the next element, making sure that it's - * a tree node or subtree. Deal with the optimization of single- - * element list versus list of size > 1. Throw an exception - * if the stream is empty or we're out of elements and size>1. - * protected so you can override in a subclass if necessary. - * </summary> - */ - protected virtual object NextCore() - { - int n = Count; - if ( n == 0 ) - { - throw new RewriteEmptyStreamException( elementDescription ); - } - if ( cursor >= n ) - { // out of elements? - if ( n == 1 ) - { // if size is 1, it's ok; return and we'll dup - return ToTree( singleElement ); - } - // out of elements and size was not 1, so we can't dup - throw new RewriteCardinalityException( elementDescription ); - } - // we have elements - if ( singleElement != null ) - { - cursor++; // move cursor even for single element list - return ToTree( singleElement ); - } - // must have more than one in list, pull from elements - object o = ToTree( elements[cursor] ); - cursor++; - return o; - } - - /** <summary> - * When constructing trees, sometimes we need to dup a token or AST - * subtree. Dup'ing a token means just creating another AST node - * around it. For trees, you must call the adaptor.dupTree() unless - * the element is for a tree root; then it must be a node dup. - * </summary> - */ - protected abstract object Dup( object el ); - - /** <summary> - * Ensure stream emits trees; tokens must be converted to AST nodes. - * AST nodes can be passed through unmolested. - * </summary> - */ - protected virtual object ToTree( object el ) - { - return el; - } - - public virtual bool HasNext - { - get - { - return ( singleElement != null && cursor < 1 ) || - ( elements != null && cursor < elements.Count ); - } - } - - public virtual int Count - { - get - { - int n = 0; - if ( singleElement != null ) - { - n = 1; - } - if ( elements != null ) - { - return elements.Count; - } - return n; - } - } - - public virtual string Description - { - get - { - return elementDescription; - } - } - } -} |