1 //===- LineIterator.h - Iterator to read a text buffer's lines --*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef LLVM_SUPPORT_LINEITERATOR_H 11 #define LLVM_SUPPORT_LINEITERATOR_H 12 13 #include "llvm/ADT/StringRef.h" 14 #include "llvm/Support/DataTypes.h" 15 #include <iterator> 16 17 namespace llvm { 18 19 class MemoryBuffer; 20 21 /// \brief A forward iterator which reads text lines from a buffer. 22 /// 23 /// This class provides a forward iterator interface for reading one line at 24 /// a time from a buffer. When default constructed the iterator will be the 25 /// "end" iterator. 26 /// 27 /// The iterator is aware of what line number it is currently processing. It 28 /// strips blank lines by default, and comment lines given a comment-starting 29 /// character. 30 /// 31 /// Note that this iterator requires the buffer to be nul terminated. 32 class line_iterator 33 : public std::iterator<std::forward_iterator_tag, StringRef> { 34 const MemoryBuffer *Buffer; 35 char CommentMarker; 36 bool SkipBlanks; 37 38 unsigned LineNumber; 39 StringRef CurrentLine; 40 41 public: 42 /// \brief Default construct an "end" iterator. 43 line_iterator() : Buffer(nullptr) {} 44 45 /// \brief Construct a new iterator around some memory buffer. 46 explicit line_iterator(const MemoryBuffer &Buffer, bool SkipBlanks = true, 47 char CommentMarker = '\0'); 48 49 /// \brief Return true if we've reached EOF or are an "end" iterator. 50 bool is_at_eof() const { return !Buffer; } 51 52 /// \brief Return true if we're an "end" iterator or have reached EOF. 53 bool is_at_end() const { return is_at_eof(); } 54 55 /// \brief Return the current line number. May return any number at EOF. 56 int64_t line_number() const { return LineNumber; } 57 58 /// \brief Advance to the next (non-empty, non-comment) line. 59 line_iterator &operator++() { 60 advance(); 61 return *this; 62 } 63 line_iterator operator++(int) { 64 line_iterator tmp(*this); 65 advance(); 66 return tmp; 67 } 68 69 /// \brief Get the current line as a \c StringRef. 70 StringRef operator*() const { return CurrentLine; } 71 const StringRef *operator->() const { return &CurrentLine; } 72 73 friend bool operator==(const line_iterator &LHS, const line_iterator &RHS) { 74 return LHS.Buffer == RHS.Buffer && 75 LHS.CurrentLine.begin() == RHS.CurrentLine.begin(); 76 } 77 78 friend bool operator!=(const line_iterator &LHS, const line_iterator &RHS) { 79 return !(LHS == RHS); 80 } 81 82 private: 83 /// \brief Advance the iterator to the next line. 84 void advance(); 85 }; 86 } 87 88 #endif 89
