thirdparty/libantlr3c-3.2/include/antlr3intstream.h

   1 /** \file
   2  * Defines the the class interface for an antlr3 INTSTREAM.
   3  *
   4  * Certain functionality (such as DFAs for instance) abstract the stream of tokens
   5  * or characters in to a steam of integers. Hence this structure should be included
   6  * in any stream that is able to provide the output as a stream of integers (which is anything
   7  * basically.
   8  *
   9  * There are no specific implementations of the methods in this interface in general. Though
  10  * for purposes of casting and so on, it may be necesssary to implement a function with
  11  * the signature in this interface which abstracts the base immplementation. In essence though
  12  * the base stream provides a pointer to this interface, within which it installs its
  13  * normal match() functions and so on. Interaces such as DFA are then passed the pANTLR3_INT_STREAM
  14  * and can treat any input as an int stream.
  15  *
  16  * For instance, a lexer implements a pANTLR3_BASE_RECOGNIZER, within which there is a pANTLR3_INT_STREAM.
  17  * However, a pANTLR3_INPUT_STREAM also provides a pANTLR3_INT_STREAM, which it has constructed from
  18  * it's normal interface when it was created. This is then pointed at by the pANTLR_BASE_RECOGNIZER
  19  * when it is intialized with a pANTLR3_INPUT_STREAM.
  20  *
  21  * Similarly if a pANTLR3_BASE_RECOGNIZER is initialized with a pANTLR3_TOKEN_STREAM, then the
  22  * pANTLR3_INT_STREAM is taken from the pANTLR3_TOKEN_STREAM.
  23  *
  24  * If a pANTLR3_BASE_RECOGNIZER is initialized with a pANTLR3_TREENODE_STREAM, then guess where
  25  * the pANTLR3_INT_STREAM comes from?
  26  *
  27  * Note that because the context pointer points to the actual interface structure that is providing
  28  * the ANTLR3_INT_STREAM it is defined as a (void *) in this interface. There is no direct implementation
  29  * of an ANTLR3_INT_STREAM (unless someone did not understand what I was doing here =;?P
  30  */
  31 #ifndef _ANTLR3_INTSTREAM_H
  32 #define _ANTLR3_INTSTREAM_H
  33
  34 // [The "BSD licence"]
  35 // Copyright (c) 2005-2009 Jim Idle, Temporal Wave LLC
  36 // http://www.temporal-wave.com
  37 // http://www.linkedin.com/in/jimidle
  38 //
  39 // All rights reserved.
  40 //
  41 // Redistribution and use in source and binary forms, with or without
  42 // modification, are permitted provided that the following conditions
  43 // are met:
  44 // 1. Redistributions of source code must retain the above copyright
  45 //    notice, this list of conditions and the following disclaimer.
  46 // 2. Redistributions in binary form must reproduce the above copyright
  47 //    notice, this list of conditions and the following disclaimer in the
  48 //    documentation and/or other materials provided with the distribution.
  49 // 3. The name of the author may not be used to endorse or promote products
  50 //    derived from this software without specific prior written permission.
  51 //
  52 // THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  53 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  54 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  55 // IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  56 // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  57 // NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  58 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  59 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  60 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  61 // THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  62
  63 #include    <antlr3defs.h>
  64 #include    <antlr3commontoken.h>
  65
  66 /** Type indicator for a character stream
  67  * \remark if a custom stream is created but it can be treated as
  68  * a char stream, then you may OR in this value to your type indicator
  69  */
  70 #define ANTLR3_CHARSTREAM       0x0001
  71
  72 /** Type indicator for a Token stream
  73  * \remark if a custom stream is created but it can be treated as
  74  * a token stream, then you may OR in this value to your type indicator
  75  */
  76 #define ANTLR3_TOKENSTREAM      0x0002
  77
  78 /** Type indicator for a common tree node stream
  79  * \remark if a custom stream is created but it can be treated as
  80  * a common tree node stream, then you may OR in this value to your type indicator
  81  */
  82 #define ANTLR3_COMMONTREENODE   0x0004
  83
  84 /** Type mask for input stream so we can switch in the above types
  85  *  \remark DO NOT USE 0x0000 as a stream type!
  86  */
  87 #define ANTLR3_INPUT_MASK       0x0007
  88
  89 #ifdef __cplusplus
  90 extern "C" {
  91 #endif
  92
  93 typedef struct ANTLR3_INT_STREAM_struct
  94 {
  95     /** Input stream type indicator. Sometimes useful for error reporting etc.
  96      */
  97     ANTLR3_UINT32           type;
  98
  99     /** Potentially useful in error reporting and so on, this string is
 100      *  an identification of the input source. It may be NULL, so anything
 101      *  attempting to access it needs to check this and substitute a sensible
 102      *  default.
 103      */
 104     pANTLR3_STRING            streamName;
 105
 106     /** Pointer to the super structure that contains this interface. This
 107      *  will usually be a token stream or a tree stream.
 108      */
 109     void                    * super;
 110
 111     /** Last marker position allocated
 112      */
 113     ANTLR3_MARKER           lastMarker;
 114
 115         // Return a string that identifies the input source
 116         //
 117         pANTLR3_STRING          (*getSourceName)        (struct ANTLR3_INT_STREAM_struct * intStream);
 118
 119     /** Consume the next 'ANTR3_UINT32' in the stream
 120      */
 121     void                    (*consume)      (struct ANTLR3_INT_STREAM_struct * intStream);
 122
 123     /** Get ANTLR3_UINT32 at current input pointer + i ahead where i=1 is next ANTLR3_UINT32
 124      */
 125     ANTLR3_UINT32           (*_LA)          (struct ANTLR3_INT_STREAM_struct * intStream, ANTLR3_INT32 i);
 126
 127     /** Tell the stream to start buffering if it hasn't already.  Return
 128      *  current input position, index(), or some other marker so that
 129      *  when passed to rewind() you get back to the same spot.
 130      *  rewind(mark()) should not affect the input cursor.
 131      */
 132     ANTLR3_MARKER           (*mark)         (struct ANTLR3_INT_STREAM_struct * intStream);
 133
 134     /** Return the current input symbol index 0..n where n indicates the
 135      *  last symbol has been read.
 136      */
 137     ANTLR3_MARKER           (*index)        (struct ANTLR3_INT_STREAM_struct * intStream);
 138
 139     /** Reset the stream so that next call to index would return marker.
 140      *  The marker will usually be index() but it doesn't have to be.  It's
 141      *  just a marker to indicate what state the stream was in.  This is
 142      *  essentially calling release() and seek().  If there are markers
 143      *  created after this marker argument, this routine must unroll them
 144      *  like a stack.  Assume the state the stream was in when this marker
 145      *  was created.
 146      */
 147     void                    (*rewind)       (struct ANTLR3_INT_STREAM_struct * intStream, ANTLR3_MARKER marker);
 148
 149     /** Reset the stream to the last marker position, witouh destryoing the
 150      *  last marker position.
 151      */
 152     void                    (*rewindLast)   (struct ANTLR3_INT_STREAM_struct * intStream);
 153
 154     /** You may want to commit to a backtrack but don't want to force the
 155      *  stream to keep bookkeeping objects around for a marker that is
 156      *  no longer necessary.  This will have the same behavior as
 157      *  rewind() except it releases resources without the backward seek.
 158      */
 159     void                    (*release)      (struct ANTLR3_INT_STREAM_struct * intStream, ANTLR3_MARKER mark);
 160
 161     /** Set the input cursor to the position indicated by index.  This is
 162      *  normally used to seek ahead in the input stream.  No buffering is
 163      *  required to do this unless you know your stream will use seek to
 164      *  move backwards such as when backtracking.
 165      *
 166      *  This is different from rewind in its multi-directional
 167      *  requirement and in that its argument is strictly an input cursor (index).
 168      *
 169      *  For char streams, seeking forward must update the stream state such
 170      *  as line number.  For seeking backwards, you will be presumably
 171      *  backtracking using the mark/rewind mechanism that restores state and
 172      *  so this method does not need to update state when seeking backwards.
 173      *
 174      *  Currently, this method is only used for efficient backtracking, but
 175      *  in the future it may be used for incremental parsing.
 176      */
 177     void                    (*seek)         (struct ANTLR3_INT_STREAM_struct * intStream, ANTLR3_MARKER index);
 178
 179     /** Only makes sense for streams that buffer everything up probably, but
 180      *  might be useful to display the entire stream or for testing.
 181      */
 182     ANTLR3_UINT32           (*size)         (struct ANTLR3_INT_STREAM_struct * intStream);
 183
 184     /** Because the indirect call, though small in individual cases can
 185      *  mount up if there are thousands of tokens (very large input streams), callers
 186      *  of size can optionally use this cached size field.
 187      */
 188     ANTLR3_UINT32           cachedSize;
 189
 190     /** Frees any resources that were allocated for the implementation of this
 191      *  interface. Usually this is just releasing the memory allocated
 192      *  for the structure itself, but it may of course do anything it need to
 193      *  so long as it does not stamp on anything else.
 194      */
 195     void                    (*free)         (struct ANTLR3_INT_STREAM_struct * stream);
 196
 197 }
 198     ANTLR3_INT_STREAM;
 199
 200 #ifdef __cplusplus
 201 }
 202 #endif
 203
 204 #endif
 205