src/gromacs/utility/textreader.h

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  35 /*! \libinternal \file
  36  * \brief
  37  * Declares gmx::TextReader.
  38  *
  39  * \author Teemu Murtola <teemu.murtola@gmail.com>
  40  * \inlibraryapi
  41  * \ingroup module_utility
  42  */
  43 #ifndef GMX_UTILITY_TEXTREADER_H
  44 #define GMX_UTILITY_TEXTREADER_H
  45
  46 #include <string>
  47
  48 #include "gromacs/utility/classhelpers.h"
  49 #include "gromacs/utility/textstream.h"
  50
  51 namespace gmx
  52 {
  53
  54 /*! \libinternal \brief
  55  * Reads text from a TextInputStream.
  56  *
  57  * This class provides more formatted reading capabilities than reading raw
  58  * lines from the stream (and a natural place to implement more such
  59  * capabilities).
  60  *
  61  * All methods that read from the stream can throw any exceptions that the
  62  * underlying stream throws.
  63  *
  64  * \inlibraryapi
  65  * \ingroup module_utility
  66  */
  67 class TextReader
  68 {
  69     public:
  70         /*! \brief
  71          * Reads contents of a file to a std::string.
  72          *
  73          * \param[in] filename  Name of the file to read.
  74          * \returns   The contents of \p filename.
  75          * \throws    std::bad_alloc if out of memory.
  76          * \throws    FileIOError on any I/O error.
  77          */
  78         static std::string readFileToString(const char *filename);
  79         //! \copydoc readFileToString(const char *)
  80         static std::string readFileToString(const std::string &filename);
  81
  82         /*! \brief
  83          * Creates a reader that reads from specified file.
  84          *
  85          * \param[in]  filename  Path to the file to open.
  86          * \throws     std::bad_alloc if out of memory.
  87          * \throws     FileIOError on any I/O error.
  88          *
  89          * This constructor is provided for convenience for reading directly
  90          * from a file, without the need to construct multiple objects.
  91          */
  92         explicit TextReader(const std::string &filename);
  93         /*! \brief
  94          * Creates a reader that reads from specified stream.
  95          *
  96          * \param[in]  stream  Stream to read from.
  97          * \throws     std::bad_alloc if out of memory.
  98          *
  99          * The caller is responsible of the lifetime of the stream (should
 100          * remain in existence as long as the reader exists).
 101          *
 102          * This constructor is provided for convenience for cases where the
 103          * stream is not allocated with `new` and/or not managed by a
 104          * std::shared_ptr (e.g., if the stream is an object on the stack).
 105          */
 106         explicit TextReader(TextInputStream *stream);
 107         /*! \brief
 108          * Creates a reader that reads from specified stream.
 109          *
 110          * \param[in]  stream  Stream to read from.
 111          * \throws     std::bad_alloc if out of memory.
 112          *
 113          * The reader keeps a reference to the stream, so the caller can pass
 114          * in a temporary if necessary.
 115          */
 116         explicit TextReader(const TextInputStreamPointer &stream);
 117         ~TextReader();
 118
 119         /*! \brief
 120          * Reads a single line (including newline) from the stream.
 121          *
 122          * \param[out] line    String to receive the line.
 123          * \returns    `false` if nothing was read because the file ended.
 124          *
 125          * On error or when false is returned, \p line will be empty.
 126          * Newlines will be returned as part of \p line if it was present in
 127          * the stream.
 128          * To loop over all lines in the stream, use:
 129          * \code
 130            std::string line;
 131            while (reader.readLine(&line))
 132            {
 133                // ...
 134            }
 135            \endcode
 136          *
 137          * Behaviours such as trimming whitespace or comments can be
 138          * configured by calling other methods before this one.
 139          */
 140         bool readLine(std::string *line);
 141         /*! \brief Sets whether the reader should trim leading whitespace
 142          * from a line before returning it.
 143          *
 144          * \param[in] doTrimming  Whether trimming should be active.
 145          */
 146         void setTrimLeadingWhiteSpace(bool doTrimming);
 147         /*! \brief Sets whether the reader should trim trailing whitespace
 148          * from a line before returning it.
 149          *
 150          * Note that comment trimming will precede whitespace trimming
 151          * when both are active.
 152          *
 153          * \param[in] doTrimming  Whether trimming should be active.
 154          */
 155         void setTrimTrailingWhiteSpace(bool doTrimming);
 156         /*! \brief Sets whether the reader should trim at trailing
 157          * comment from a line before returning it.
 158          *
 159          * Note that comment trimming will precede whitespace trimming
 160          * when both are active.
 161          *
 162          * \param[in]  commentChar  The character that begins a comment.
 163          *
 164          * \param[in] doTrimming  Whether trimming should be active.
 165          */
 166         void setTrimTrailingComment(bool doTrimming, char commentChar);
 167         /*! \brief
 168          * Reads all remaining lines from the stream as a single string.
 169          *
 170          * \returns   Full contents of the stream (from the current point to
 171          *     the end).
 172          */
 173         std::string readAll();
 174
 175         /*! \brief
 176          * Closes the underlying stream.
 177          */
 178         void close();
 179
 180     private:
 181         class Impl;
 182
 183         PrivateImplPointer<Impl> impl_;
 184 };
 185
 186 } // namespace gmx
 187
 188 #endif