#ifndef ANTLR3REWRITESTREAM_H
#define ANTLR3REWRITESTREAM_H

// [The "BSD licence"]
// Copyright (c) 2005-2009 Jim Idle, Temporal Wave LLC
// http://www.temporal-wave.com
// http://www.linkedin.com/in/jimidle
//
// 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.

#include    <antlr3defs.h>
#include    <antlr3collections.h>
#include    <antlr3commontreeadaptor.h>
#include        <antlr3baserecognizer.h>

#ifdef __cplusplus
extern "C" {
#endif

/// A generic list of elements tracked in an alternative to be used in
/// a -> rewrite rule.
///
/// In the C implementation, all tree oriented streams return a pointer to
/// the same type: pANTLR3_BASE_TREE. Anything that has subclassed from this
/// still passes this type, within which there is a super pointer, which points
/// to it's own data and methods. Hence we do not need to implement this as
/// the equivalent of an abstract class, but just fill in the appropriate interface
/// as usual with this model.
///
/// Once you start next()ing, do not try to add more elements.  It will
/// break the cursor tracking I believe.
///
///
/// \see #pANTLR3_REWRITE_RULE_NODE_STREAM
/// \see #pANTLR3_REWRITE_RULE_ELEMENT_STREAM
/// \see #pANTLR3_REWRITE_RULE_SUBTREE_STREAM
///
/// TODO: add mechanism to detect/puke on modification after reading from stream
///
typedef struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct
{

    /// Cursor 0..n-1.  If singleElement!=NULL, cursor is 0 until you next(),
    /// which bumps it to 1 meaning no more elements.
    ///
    ANTLR3_UINT32                 cursor;

    /// Track single elements w/o creating a list.  Upon 2nd add, alloc list
    ///
    void                        * singleElement;

    /// The list of tokens or subtrees we are tracking
    ///
    pANTLR3_VECTOR                elements;

    /// Indicates whether we should free the vector or it was supplied to us
    ///
    ANTLR3_BOOLEAN                freeElements;

    /// 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.
    ///
    void                                * elementDescription;

        /// Pointer to the tree adaptor in use for this stream
        ///
    pANTLR3_BASE_TREE_ADAPTOR     adaptor;

        /// Once a node / subtree has been used in a stream, it must be dup'ed
        /// from then on.  Streams are reset after sub rules so that the streams
        /// can be reused in future sub rules.  So, reset must set a dirty bit.
        /// If dirty, then next() always returns a dup.
        ///
        ANTLR3_BOOLEAN                          dirty;

        // Pointer to the recognizer shared state to which this stream belongs
        //
        pANTLR3_BASE_RECOGNIZER         rec;

    //   Methods

    /// Reset the condition of this stream so that it appears we have
    ///  not consumed any of its elements.  Elements themselves are untouched.
    ///
    void                (*reset)                                (struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct * stream);

    /// Add a new pANTLR3_BASE_TREE to this stream
    ///
    void                (*add)                                  (struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct * stream, void *el, void (ANTLR3_CDECL *freePtr)(void *));

    /// 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].
    ///
        void *                                  (*next)                                 (struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct * stream);
    pANTLR3_BASE_TREE           (*nextTree)                             (struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct * stream);
    void *                                      (*nextToken)                    (struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct * stream);
    void *                                      (*_next)                                (struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct * stream);

    /// 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().
    ///
    void *              (*dup)                                  (struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct * stream, void * el);

    /// Ensure stream emits trees; tokens must be converted to AST nodes.
    /// AST nodes can be passed through unmolested.
    ///
    pANTLR3_BASE_TREE   (*toTree)               (struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct * stream, void * el);

    /// Returns ANTLR3_TRUE if there is a next element available
    ///
    ANTLR3_BOOLEAN      (*hasNext)                      (struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct * stream);

    /// Treat next element as a single node even if it's a subtree.
    /// This is used instead of next() when the result has to be a
    /// tree root node.  Also prevents us from duplicating recently-added
    /// children; e.g., ^(type ID)+ adds ID to type and then 2nd iteration
    /// must dup the type node, but ID has been added.
    ///
    /// Referencing to a rule result twice is ok; dup entire tree as
    /// we can't be adding trees; e.g., expr expr.
    ///
    pANTLR3_BASE_TREE   (*nextNode)             (struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct * stream);

    /// Number of elements available in the stream
    ///
    ANTLR3_UINT32       (*size)                         (struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct * stream);

    /// Returns the description string if there is one available (check for NULL).
    ///
    void *                      (*getDescription)       (struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct * stream);

    void                (*free)                                 (struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct * stream);

}
    ANTLR3_REWRITE_RULE_ELEMENT_STREAM;

/// This is an implementation of a token stream, which is basically an element
///  stream that deals with tokens only.
///
typedef struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct ANTLR3_REWRITE_RULE_TOKEN_STREAM;

/// This is an implementation of a subtree stream which is a set of trees
///  modelled as an element stream.
///
typedef struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct ANTLR3_REWRITE_RULE_SUBTREE_STREAM;

/// This is an implementation of a node stream, which is basically an element
///  stream that deals with tree nodes only.
///
typedef struct ANTLR3_REWRITE_RULE_ELEMENT_STREAM_struct ANTLR3_REWRITE_RULE_NODE_STREAM;

#ifdef __cplusplus
}
#endif

#endif
