1/* ANTLR Translator Generator 2 * Project led by Terence Parr at http://www.jGuru.com 3 * Software rights: http://www.antlr.org/license.html 4 * 5 * $Id: //depot/code/org.antlr/release/antlr-2.7.7/lib/cpp/src/InputBuffer.cpp#2 $ 6 */ 7 8#include "antlr/config.hpp" 9#include "antlr/InputBuffer.hpp" 10 11#ifdef ANTLR_CXX_SUPPORTS_NAMESPACE 12namespace antlr { 13#endif 14 15/** Ensure that the character buffer is sufficiently full */ 16void InputBuffer::fill(unsigned int amount) 17{ 18 syncConsume(); 19 // Fill the buffer sufficiently to hold needed characters 20 while (queue.entries() < amount + markerOffset) 21 { 22 // Append the next character 23 queue.append(getChar()); 24 } 25} 26 27/** get the current lookahead characters as a string 28 * @warning it may treat 0 and EOF values wrong 29 */ 30ANTLR_USE_NAMESPACE(std)string InputBuffer::getLAChars( void ) const 31{ 32 ANTLR_USE_NAMESPACE(std)string ret; 33 34 for(unsigned int i = markerOffset; i < queue.entries(); i++) 35 ret += queue.elementAt(i); 36 37 return ret; 38} 39 40/** get the current marked characters as a string 41 * @warning it may treat 0 and EOF values wrong 42 */ 43ANTLR_USE_NAMESPACE(std)string InputBuffer::getMarkedChars( void ) const 44{ 45 ANTLR_USE_NAMESPACE(std)string ret; 46 47 for(unsigned int i = 0; i < markerOffset; i++) 48 ret += queue.elementAt(i); 49 50 return ret; 51} 52 53/** Return an integer marker that can be used to rewind the buffer to 54 * its current state. 55 */ 56unsigned int InputBuffer::mark() 57{ 58 syncConsume(); 59 nMarkers++; 60 return markerOffset; 61} 62 63/** Rewind the character buffer to a marker. 64 * @param mark Marker returned previously from mark() 65 */ 66void InputBuffer::rewind(unsigned int mark) 67{ 68 syncConsume(); 69 markerOffset = mark; 70 nMarkers--; 71} 72 73unsigned int InputBuffer::entries() const 74{ 75 //assert(queue.entries() >= markerOffset); 76 return (unsigned int)queue.entries() - markerOffset; 77} 78 79#ifdef ANTLR_CXX_SUPPORTS_NAMESPACE 80} 81#endif 82