1// [The "BSD licence"]
2// Copyright (c) 2006-2007 Kay Roepke 2010 Alan Condit
3// All rights reserved.
4//
5// Redistribution and use in source and binary forms, with or without
6// modification, are permitted provided that the following conditions
7// are met:
8// 1. Redistributions of source code must retain the above copyright
9//    notice, this list of conditions and the following disclaimer.
10// 2. Redistributions in binary form must reproduce the above copyright
11//    notice, this list of conditions and the following disclaimer in the
12//    documentation and/or other materials provided with the distribution.
13// 3. The name of the author may not be used to endorse or promote products
14//    derived from this software without specific prior written permission.
15//
16// THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18// OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19// IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21// NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25// THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26
27#ifndef DEBUG_DEALLOC
28#define DEBUG_DEALLOC
29#endif
30
31@protocol ANTLRIntStream < NSObject, NSCopying >
32
33- (void) consume;
34
35// Get unichar at current input pointer + i ahead where i=1 is next character as int for including ANTLRCharStreamEOF (-1) in the data range
36- (NSInteger) LA:(NSInteger) i;
37
38// Tell the stream to start buffering if it hasn't already.  Return
39// current input position, index(), or some other marker so that
40// when passed to rewind() you get back to the same spot.
41// rewind(mark()) should not affect the input cursor.
42// TODO: problem in that lexer stream returns not index but some marker
43
44- (NSInteger) mark;
45
46// Return the current input symbol index 0..n where n indicates the
47// last symbol has been read.
48
49- (NSInteger) index;
50
51- (NSUInteger) line;
52
53- (NSUInteger) charPositionInLine;
54
55// Reset the stream so that next call to index would return marker.
56// The marker will usually be -index but it doesn't have to be.  It's
57// just a marker to indicate what state the stream was in.  This is
58// essentially calling -release: and -seek:.  If there are markers
59// created after this marker argument, this routine must unroll them
60// like a stack.  Assume the state the stream was in when this marker
61// was created.
62
63- (void) rewind;
64- (void) rewind:(NSInteger) marker;
65
66// You may want to commit to a backtrack but don't want to force the
67// stream to keep bookkeeping objects around for a marker that is
68// no longer necessary.  This will have the same behavior as
69// rewind() except it releases resources without the backward seek.
70
71- (void) release:(NSInteger) marker;
72
73// Set the input cursor to the position indicated by index.  This is
74// normally used to seek ahead in the input stream.  No buffering is
75// required to do this unless you know your stream will use seek to
76// move backwards such as when backtracking.
77// This is different from rewind in its multi-directional
78// requirement and in that its argument is strictly an input cursor (index).
79//
80// For char streams, seeking forward must update the stream state such
81// as line number.  For seeking backwards, you will be presumably
82// backtracking using the mark/rewind mechanism that restores state and
83// so this method does not need to update state when seeking backwards.
84//
85// Currently, this method is only used for efficient backtracking, but
86// in the future it may be used for incremental parsing.
87
88- (void) seek:(NSInteger) anIndex;
89
90/** Only makes sense for streams that buffer everything up probably, but
91 *  might be useful to display the entire stream or for testing.  This
92 *  value includes a single EOF.
93 */
94- (NSUInteger) size;
95/** Where are you getting symbols from?  Normally, implementations will
96 *  pass the buck all the way to the lexer who can ask its input stream
97 *  for the file name or whatever.
98 */
99- (NSString *)getSourceName;
100
101//@property (assign) NSInteger index;
102//@property (assign) NSUInteger line;
103//@property (assign) NSUInteger charPositionInLine;
104
105
106@end
107