lalr1.cc: extract stack.hh.

[bison.git] / data / stack.hh

diff --git a/data/stack.hh b/data/stack.hh
new file mode 100644 (file)
index 0000000..e785e80
--- /dev/null
+++ b/data/stack.hh
@@ -0,0 +1,121 @@
+# C++ skeleton for Bison
+
+# Copyright (C) 2002-2012 Free Software Foundation, Inc.
+
+# This program 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 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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 program.  If not, see <http://www.gnu.org/licenses/>.
+
+m4_pushdef([b4_copyright_years],
+           [2002-2012])
+
+# We do want M4 expansion after # for CPP macros.
+m4_changecom()
+m4_divert_push(0)dnl
+@output(b4_dir_prefix[]stack.hh@)@
+b4_copyright([Stack handling for Bison parsers in C++],
+             [2002-2012])[
+
+#ifndef BISON_STACK_HH
+# define BISON_STACK_HH
+
+# include <deque>
+
+]b4_namespace_open[
+  template <class T, class S = std::deque<T> >
+  class stack
+  {
+  public:
+    // Hide our reversed order.
+    typedef typename S::reverse_iterator iterator;
+    typedef typename S::const_reverse_iterator const_iterator;
+
+    stack () : seq_ ()
+    {
+    }
+
+    stack (unsigned int n) : seq_ (n)
+    {
+    }
+
+    inline
+    T&
+    operator [] (unsigned int i)
+    {
+      return seq_[i];
+    }
+
+    inline
+    const T&
+    operator [] (unsigned int i) const
+    {
+      return seq_[i];
+    }
+
+    inline
+    void
+    push (const T& t)
+    {
+      seq_.push_front (t);
+    }
+
+    inline
+    void
+    pop (unsigned int n = 1)
+    {
+      for (; n; --n)
+        seq_.pop_front ();
+    }
+
+    inline
+    unsigned int
+    height () const
+    {
+      return seq_.size ();
+    }
+
+    inline const_iterator begin () const { return seq_.rbegin (); }
+    inline const_iterator end () const { return seq_.rend (); }
+
+  private:
+    S seq_;
+  };
+
+  /// Present a slice of the top of a stack.
+  template <class T, class S = stack<T> >
+  class slice
+  {
+  public:
+    slice (const S& stack, unsigned int range)
+      : stack_ (stack)
+      , range_ (range)
+    {
+    }
+
+    inline
+    const T&
+    operator [] (unsigned int i) const
+    {
+      return stack_[range_ - i];
+    }
+
+  private:
+    const S& stack_;
+    unsigned int range_;
+  };
+]b4_namespace_close[
+
+#endif // not BISON_STACK_HH[]dnl
+]
+m4_divert_pop(0)
+m4_popdef([b4_copyright_years])dnl
+m4_changecom([#])