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 28 #import "IntStream.h" 29 #import "Token.h" 30 31 @protocol TokenStream < IntStream > 32 33 // Get Token at current input pointer + i ahead where i=1 is next Token. 34 // i<0 indicates tokens in the past. So -1 is previous token and -2 is 35 // two tokens ago. LT:0 is undefined. For i>=n, return Token.EOFToken. 36 // Return null for LT:0 and any index that results in an absolute address 37 // that is negative. 38 39 - (id<Token>) LT:(NSInteger) i; 40 41 - (id<Token>) getToken:(NSUInteger) i; 42 43 - (id) getTokenSource; 44 45 - (NSString *) toString; 46 /** Return the text of all tokens from start to stop, inclusive. 47 * If the stream does not buffer all the tokens then it can just 48 * return "" or null; Users should not access $ruleLabel.text in 49 * an action of course in that case. 50 */ 51 - (NSString *)toStringFromStart:(NSInteger)startIdx ToEnd:(NSInteger)stopIdx; 52 53 /** Because the user is not required to use a token with an index stored 54 * in it, we must provide a means for two token objects themselves to 55 * indicate the start/end location. Most often this will just delegate 56 * to the other toString(int,int). This is also parallel with 57 * the TreeNodeStream.toString(Object,Object). 58 */ 59 - (NSString *) toStringFromToken:(id<Token>)startToken ToToken:(id<Token>)stopToken; 60 61 62 @end 63