llvm-6502/include/llvm/Support/LineIterator.h
Chandler Carruth 5ff21b4111 Introduce a simple line-by-line iterator type into the Support library.
This is an iterator which you can build around a MemoryBuffer. It will
iterate through the non-empty, non-comment lines of the buffer as
a forward iterator. It should be small and reasonably fast (although it
could be made much faster if anyone cares, I don't really...).

This will be used to more simply support the text-based sample
profile file format, and is largely based on the original patch by
Diego. I've re-worked the style of it and separated it from the work of
producing a MemoryBuffer from a file which both simplifies the interface
and makes it easier to test.

The style of the API follows the C++ standard naming conventions to fit
in better with iterators in general, much like the Path and FileSystem
interfaces follow standard-based naming conventions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198068 91177308-0d34-0410-b5e6-96231b3b80d8
2013-12-27 04:28:57 +00:00

74 lines
2.3 KiB
C++

//===- LineIterator.h - Iterator to read a text buffer's lines --*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/StringRef.h"
#include <iterator>
namespace llvm {
class MemoryBuffer;
/// \brief A forward iterator which reads non-blank text lines from a buffer.
///
/// This class provides a forward iterator interface for reading one line at
/// a time from a buffer. When default constructed the iterator will be the
/// "end" iterator.
///
/// The iterator also is aware of what line number it is currently processing
/// and can strip comment lines given the comment-starting character.
///
/// Note that this iterator requires the buffer to be nul terminated.
class line_iterator
: public std::iterator<std::forward_iterator_tag, StringRef, ptrdiff_t> {
const MemoryBuffer *Buffer;
char CommentMarker;
unsigned LineNumber;
StringRef CurrentLine;
public:
/// \brief Default construct an "end" iterator.
line_iterator() : Buffer(0) {}
/// \brief Construct a new iterator around some memory buffer.
explicit line_iterator(const MemoryBuffer &Buffer, char CommentMarker = '\0');
/// \brief Return true if we've reached EOF or are an "end" iterator.
bool is_at_eof() const { return !Buffer; }
/// \brief Return true if we're an "end" iterator or have reached EOF.
bool is_at_end() const { return is_at_eof(); }
/// \brief Return the current line number. May return any number at EOF.
int64_t line_number() const { return LineNumber; }
/// \brief Advance to the next (non-empty, non-comment) line.
line_iterator &operator++() {
advance();
return *this;
}
/// \brief Get the current line as a \c StringRef.
StringRef operator*() const { return CurrentLine; }
friend bool operator==(const line_iterator &LHS, const line_iterator &RHS) {
return LHS.Buffer == RHS.Buffer &&
LHS.CurrentLine.begin() == RHS.CurrentLine.begin();
}
friend bool operator!=(const line_iterator &LHS, const line_iterator &RHS) {
return !(LHS == RHS);
}
private:
/// \brief Advance the iterator to the next line.
void advance();
};
}