+@output position.hh
+b4_copyright([Position class for Bison C++ parsers], [2002, 2003, 2004, 2005])[
+
+/**
+ ** \file position.hh
+ ** Define the position class.
+ */
+
+#ifndef BISON_POSITION_HH
+# define BISON_POSITION_HH
+
+# include <iostream>
+# include <string>
+
+namespace yy
+{
+ /// Abstract a position.
+ class position
+ {
+ public:
+ /// Initial column number.
+ static const unsigned int initial_column = 0;
+ /// Initial line number.
+ static const unsigned int initial_line = 1;
+
+ /** \name Ctor & dtor.
+ ** \{ */
+ public:
+ /// Construct a position.
+ position () :
+ filename (0),
+ line (initial_line),
+ column (initial_column)
+ {
+ }
+ /** \} */
+
+
+ /** \name Line and Column related manipulators
+ ** \{ */
+ public:
+ /// (line related) Advance to the COUNT next lines.
+ inline void lines (int count = 1)
+ {
+ column = initial_column;
+ line += count;
+ }
+
+ /// (column related) Advance to the COUNT next columns.
+ inline void columns (int count = 1)
+ {
+ int leftmost = initial_column;
+ int current = column;
+ if (leftmost <= current + count)
+ column += count;
+ else
+ column = initial_column;
+ }
+ /** \} */
+
+ public:
+ /// File name to which this position refers.
+ ]b4_filename_type[* filename;
+ /// Current line number.
+ unsigned int line;
+ /// Current column number.
+ unsigned int column;
+ };
+
+ /// Add and assign a position.
+ inline const position&
+ operator+= (position& res, const int width)
+ {
+ res.columns (width);
+ return res;
+ }
+
+ /// Add two position objects.
+ inline const position
+ operator+ (const position& begin, const int width)
+ {
+ position res = begin;
+ return res += width;
+ }
+
+ /// Add and assign a position.
+ inline const position&
+ operator-= (position& res, const int width)
+ {
+ return res += -width;
+ }
+
+ /// Add two position objects.
+ inline const position
+ operator- (const position& begin, const int width)
+ {
+ return begin + -width;
+ }
+
+ /** \brief Intercept output stream redirection.
+ ** \param ostr the destination output stream
+ ** \param pos a reference to the position to redirect
+ */
+ inline std::ostream&
+ operator<< (std::ostream& ostr, const position& pos)
+ {
+ if (pos.filename)
+ ostr << *pos.filename << ':';
+ return ostr << pos.line << '.' << pos.column;
+ }
+
+}
+#endif // not BISON_POSITION_HH]