Imported Upstream version 3.3.0.2upstream/3.3.0.2

1 files changed, 99 insertions, 0 deletions

diff --git a/libfrontend-elements/frontend-elements/token-stream.hxx b/libfrontend-elements/frontend-elements/token-stream.hxx
new file mode 100644
index 0000000..023842f
--- /dev/null
+++ b/libfrontend-elements/frontend-elements/token-stream.hxx
@@ -0,0 +1,99 @@
+// file      : frontend-elements/token-stream.hxx
+// author    : Boris Kolpackov <boris@kolpackov.net>
+// copyright : Copyright (c) 2005-2010 Boris Kolpackov
+// license   : GNU GPL v2 + exceptions; see accompanying LICENSE file
+
+#ifndef FRONTEND_ELEMENTS_TOKEN_STREAM_HXX
+#define FRONTEND_ELEMENTS_TOKEN_STREAM_HXX
+
+#include <frontend-elements/types.hxx>
+
+#include <string>   // std::char_traits
+#include <istream>
+
+namespace FrontendElements
+{
+  //
+  //
+  template <typename Token>
+  class TokenStream
+  {
+  public:
+    virtual
+    ~TokenStream ()
+    {
+    }
+
+  public:
+    virtual Token
+    next () = 0;
+  };
+
+
+  //
+  //
+  template <>
+  class TokenStream<Char>
+  {
+  public:
+    typedef
+    std::char_traits<FrontendElements::Char>
+    Traits;
+
+    typedef
+    Traits::int_type
+    AsInt;
+
+    typedef
+    Traits::char_type
+    AsChar;
+
+  public:
+    virtual
+    ~TokenStream ()
+    {
+    }
+
+  public:
+    virtual AsInt
+    next () = 0;
+
+    static AsChar
+    to_char (AsInt i)
+    {
+      return Traits::to_char_type (i);
+    }
+
+    static AsInt
+    eos ()
+    {
+      return Traits::eof ();
+    }
+  };
+
+  class InputStreamAdapter: public TokenStream<Char>
+  {
+  public:
+    virtual
+    ~InputStreamAdapter ()
+    {
+    }
+
+    InputStreamAdapter (std::istream& is)
+        : is_ (is)
+    {
+    }
+
+  public:
+    virtual AsInt
+    next ()
+    {
+      return is_.get ();
+    }
+
+  private:
+    std::istream& is_;
+  };
+}
+
+#endif  // FRONTEND_ELEMENTS_TOKEN_STREAM_HXX