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@protocol ANTLRIntStream < NSObject, NSCopying > 28 29- (void) consume; 30 31// Get unichar at current input pointer + i ahead where i=1 is next character as int for including ANTLRCharStreamEOF (-1) in the data range 32- (NSInteger) LA:(NSInteger) i; 33 34// Tell the stream to start buffering if it hasn't already. Return 35// current input position, index(), or some other marker so that 36// when passed to rewind() you get back to the same spot. 37// rewind(mark()) should not affect the input cursor. 38// TODO: problem in that lexer stream returns not index but some marker 39 40- (NSInteger) mark; 41 42// Return the current input symbol index 0..n where n indicates the 43// last symbol has been read. 44 45- (NSInteger) getIndex; 46 47// Reset the stream so that next call to index would return marker. 48// The marker will usually be -index but it doesn't have to be. It's 49// just a marker to indicate what state the stream was in. This is 50// essentially calling -release: and -seek:. If there are markers 51// created after this marker argument, this routine must unroll them 52// like a stack. Assume the state the stream was in when this marker 53// was created. 54 55- (void) rewind; 56- (void) rewind:(NSInteger) marker; 57 58// You may want to commit to a backtrack but don't want to force the 59// stream to keep bookkeeping objects around for a marker that is 60// no longer necessary. This will have the same behavior as 61// rewind() except it releases resources without the backward seek. 62 63- (void) release:(NSInteger) marker; 64 65// Set the input cursor to the position indicated by index. This is 66// normally used to seek ahead in the input stream. No buffering is 67// required to do this unless you know your stream will use seek to 68// move backwards such as when backtracking. 69// This is different from rewind in its multi-directional 70// requirement and in that its argument is strictly an input cursor (index). 71// 72// For char streams, seeking forward must update the stream state such 73// as line number. For seeking backwards, you will be presumably 74// backtracking using the mark/rewind mechanism that restores state and 75// so this method does not need to update state when seeking backwards. 76// 77// Currently, this method is only used for efficient backtracking, but 78// in the future it may be used for incremental parsing. 79 80- (void) seek:(NSInteger) index; 81 82/** Only makes sense for streams that buffer everything up probably, but 83 * might be useful to display the entire stream or for testing. This 84 * value includes a single EOF. 85 */ 86- (NSUInteger) size; 87/** Where are you getting symbols from? Normally, implementations will 88 * pass the buck all the way to the lexer who can ask its input stream 89 * for the file name or whatever. 90 */ 91- (NSString *)getSourceName; 92 93@end 94