1 files changed, 156 insertions, 0 deletions
diff --git a/libio/parsestream.h b/libio/parsestream.h
new file mode 100644
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--- /dev/null
+++ b/libio/parsestream.h
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+/* This is part of libio/iostream, providing -*- C++ -*- input/output.
+Copyright (C) 1993 Free Software Foundation
+
+This file is part of the GNU IO Library.  This library is free
+software; you can redistribute it and/or modify it under the
+terms of the GNU General Public License as published by the
+Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+This library is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this library; see the file COPYING.  If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+As a special exception, if you link this library with files
+compiled with a GNU compiler to produce an executable, this does not cause
+the resulting executable to be covered by the GNU General Public License.
+This exception does not however invalidate any other reasons why
+the executable file might be covered by the GNU General Public License.
+
+Written by Per Bothner (bothner@cygnus.com). */
+
+#ifndef PARSESTREAM_H
+#define PARSESTREAM_H
+#ifdef __GNUG__
+#pragma interface
+#endif
+#include "streambuf.h"
+
+extern "C++" {
+// A parsebuf is a streambuf optimized for scanning text files.
+// It keeps track of line and column numbers.
+// It is guaranteed to remember the entire current line,
+// as well the '\n'-s on either side of it (if they exist).
+// You can arbitrarily seek (or unget) within this extended line.
+// Other backward seeks are not supported.
+// Normal read semantics are supported (and hence istream operators like >>).
+
+class parsebuf : public streambuf {
+  protected:
+    _IO_fpos_t pos_at_line_start;
+    long _line_length;
+    unsigned long __line_number;
+    char *buf_start;
+    char *buf_end;
+
+  public:
+    parsebuf *chain;
+
+    // Return column number (raw - don't handle tabs etc).
+    // Retult can be -1, meaning: at '\n' before current line.
+    virtual int tell_in_line();
+
+    // seek to (raw) column I in current line.
+    // Result is new (raw) column position - differs from I if unable to seek.
+    // Seek to -1 tries to seek to before previous LF.
+    virtual int seek_in_line(int i);
+
+    // Note: there is no "current line" initially, until something is read.
+
+    // Current line number, starting with 0.
+    // If tell_in_line()==-1, then line number of next line.
+    int line_number() { return __line_number; }
+
+    // Length of current line, not counting either '\n'.
+    int line_length() { return _line_length; }
+    // Current line - not a copy, so file ops may trash it. 
+    virtual char* current_line();
+    virtual streampos seekoff(streamoff, _seek_dir, int mode=ios::in|ios::out);
+    virtual streambuf* setbuf(char* p, int len);
+  protected:
+    parsebuf() { chain= NULL;
+	__line_number = 0; pos_at_line_start = 0; _line_length = -1; }
+    virtual int pbackfail(int c);
+};
+
+// A string_parsebuf is a parsebuf whose source is a fixed string.
+
+class string_parsebuf : public parsebuf {
+  public:
+    int do_delete;
+    string_parsebuf(char *str, int len, int delete_at_close=0);
+    virtual int underflow();
+    virtual char* current_line();
+    virtual int seek_in_line(int i);
+    virtual int tell_in_line();
+    char *left() const { return base(); }
+    char *right() const { return ebuf(); }
+//    streampos seekoff(streamoff, _seek_dir, int);
+};
+
+// A func_parsebuf calls a given function to get new input.
+// Each call returns an entire NUL-terminated line (without the '\n').
+// That line has been allocated with malloc(), not new.
+// The interface is tailored to the GNU readline library.
+// Example:
+// char* DoReadLine(void* arg)
+// {
+//   char *line = readline((char*)arg); /* 'arg' is used as prompt. */
+//   if line == NULL) { putc('\n', stderr); return NULL; }
+//   if (line[0] != '\0') add_history(line);
+//    return line;
+// }
+// char PromptBuffer[100] = "> ";
+// func_parsebuf my_stream(DoReadLine, PromptBuffer);
+
+typedef char *(*CharReader)(void *arg);
+class istream;
+
+class func_parsebuf : public parsebuf {
+  public:
+    void *arg;
+    CharReader read_func;
+    int backed_up_to_newline;
+    func_parsebuf(CharReader func, void *argm = NULL);
+    int underflow();
+    virtual int tell_in_line();
+    virtual int seek_in_line(int i);
+    virtual char* current_line();
+};
+
+// A general_parsebuf is a parsebuf which gets its input from some
+// other streambuf. It explicitly buffers up an entire line.
+
+class general_parsebuf : public parsebuf {
+  public:
+    streambuf *sbuf;
+    int delete_buf; // Delete sbuf when destroying this.
+    general_parsebuf(streambuf *buf, int delete_arg_buf = 0);
+    int underflow();
+    virtual int tell_in_line();
+    virtual int seek_in_line(int i);
+    ~general_parsebuf();
+    virtual char* current_line();
+};
+
+#if 0
+class parsestream : public istream {
+    streammarker marks[2];
+    short _first; // of the two marks; either 0 or 1
+    int _lineno;
+    int first() { return _first; }
+    int second() { return 1-_first; }
+    int line_length() { marks[second].delta(marks[first]); }
+    int line_length() { marks[second].delta(marks[first]); }
+    int seek_in_line(int i);
+    int tell_in_line();
+    int line_number();
+};
+#endif
+} // extern "C++"
+#endif /*!defined(PARSESTREAM_H)*/