Line data    Source code

       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             : /// 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             :   /// Default construct an "end" iterator.
      43          14 :   line_iterator() : Buffer(nullptr) {}
      44             : 
      45             :   /// Construct a new iterator around some memory buffer.
      46             :   explicit line_iterator(const MemoryBuffer &Buffer, bool SkipBlanks = true,
      47             :                          char CommentMarker = '\0');
      48             : 
      49             :   /// Return true if we've reached EOF or are an "end" iterator.
      50          10 :   bool is_at_eof() const { return !Buffer; }
      51             : 
      52             :   /// Return true if we're an "end" iterator or have reached EOF.
      53      107938 :   bool is_at_end() const { return is_at_eof(); }
      54             : 
      55             :   /// Return the current line number. May return any number at EOF.
      56      347261 :   int64_t line_number() const { return LineNumber; }
      57             : 
      58             :   /// Advance to the next (non-empty, non-comment) line.
      59             :   line_iterator &operator++() {
      60      449884 :     advance();
      61             :     return *this;
      62             :   }
      63           0 :   line_iterator operator++(int) {
      64        1694 :     line_iterator tmp(*this);
      65        1876 :     advance();
      66           0 :     return tmp;
      67             :   }
      68             : 
      69             :   /// Get the current line as a \c StringRef.
      70           0 :   StringRef operator*() const { return CurrentLine; }
      71          90 :   const StringRef *operator->() const { return &CurrentLine; }
      72             : 
      73             :   friend bool operator==(const line_iterator &LHS, const line_iterator &RHS) {
      74        2765 :     return LHS.Buffer == RHS.Buffer &&
      75          51 :            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             :   /// Advance the iterator to the next line.
      84             :   void advance();
      85             : };
      86             : }
      87             : 
      88             : #endif