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 non-blank 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 also is aware of what line number it is currently processing 28 /// and can strip comment lines given the comment-starting character. 29 /// 30 /// Note that this iterator requires the buffer to be nul terminated. 31 class line_iterator 32 : public std::iterator<std::forward_iterator_tag, StringRef> { 33 const MemoryBuffer *Buffer; 34 char CommentMarker; 35 36 unsigned LineNumber; 37 StringRef CurrentLine; 38 39 public: 40 /// \brief Default construct an "end" iterator. 41 line_iterator() : Buffer(nullptr) {} 42 43 /// \brief Construct a new iterator around some memory buffer. 44 explicit line_iterator(const MemoryBuffer &Buffer, char CommentMarker = '\0'); 45 46 /// \brief Return true if we've reached EOF or are an "end" iterator. 47 bool is_at_eof() const { return !Buffer; } 48 49 /// \brief Return true if we're an "end" iterator or have reached EOF. 50 bool is_at_end() const { return is_at_eof(); } 51 52 /// \brief Return the current line number. May return any number at EOF. 53 int64_t line_number() const { return LineNumber; } 54 55 /// \brief Advance to the next (non-empty, non-comment) line. 56 line_iterator &operator++() { 57 advance(); 58 return *this; 59 } 60 line_iterator operator++(int) { 61 line_iterator tmp(*this); 62 advance(); 63 return tmp; 64 } 65 66 /// \brief Get the current line as a \c StringRef. 67 StringRef operator*() const { return CurrentLine; } 68 const StringRef *operator->() const { return &CurrentLine; } 69 70 friend bool operator==(const line_iterator &LHS, const line_iterator &RHS) { 71 return LHS.Buffer == RHS.Buffer && 72 LHS.CurrentLine.begin() == RHS.CurrentLine.begin(); 73 } 74 75 friend bool operator!=(const line_iterator &LHS, const line_iterator &RHS) { 76 return !(LHS == RHS); 77 } 78 79 private: 80 /// \brief Advance the iterator to the next line. 81 void advance(); 82 }; 83 } 84 85 #endif // LLVM_SUPPORT_LINEITERATOR_H__ 86
