start on otk::ustring (unicode/utf8)

2 files changed, 192 insertions, 0 deletions

diff --git a/otk/ustring.cc b/otk/ustring.cc
new file mode 100644
index 00000000..571f9773
--- /dev/null
+++ b/otk/ustring.cc
@@ -0,0 +1,44 @@
+// -*- mode: C++; indent-tabs-mode: nil; c-basic-offset: 2; -*-
+
+#ifdef    HAVE_CONFIG_H
+#  include "../config.h"
+#endif // HAVE_CONFIG_H
+
+#include "ustring.hh"
+
+extern "C" {
+#include <assert.h>
+}
+
+namespace otk {
+
+ustring::ustring()
+{
+}
+
+ustring::~ustring()
+{
+}
+
+ustring::ustring(const ustring& other)
+  : _string(other._string)
+{
+}
+
+ustring& ustring::operator=(const ustring& other)
+{
+  _string = other._string;
+  return *this;
+}
+
+ustring::ustring(const std::string& src)
+  : _string(src)
+{
+}
+
+ustring::ustring(const char* src)
+  : _string(src)
+{
+}
+
+}
diff --git a/otk/ustring.hh b/otk/ustring.hh
new file mode 100644
index 00000000..5d011cfc
--- /dev/null
+++ b/otk/ustring.hh
@@ -0,0 +1,148 @@
+// -*- mode: C++; indent-tabs-mode: nil; c-basic-offset: 2; -*-
+#ifndef   __ustring_hh
+#define   __ustring_hh
+
+/*! @file ustring.hh
+  @brief Provides a simple UTF-8 encoded string
+*/
+
+extern "C" {
+#ifdef HAVE_STDINT_H
+#  include <stdint.h>
+#else
+#  ifdef HAVE_SYS_TYPES_H
+#    include <sys/types.h>
+#  endif
+#endif
+}
+
+#include <string>
+
+namespace otk {
+
+//! The number of bytes to skip to find the next character in the string
+const char g_utf8_skip[256] = {
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+  2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,
+  3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,6,6,1,1
+};
+
+#ifdef HAVE_STDINT_H
+typedef uint32_t unichar;
+#else
+typedef u_int32_t unichar;
+#endif
+
+//! The iterator type for ustring
+/*!
+  Note this is not a random access iterator but a bidirectional one, since all
+  index operations need to iterate over the UTF-8 data.  Use std::advance() to
+  move to a certain position.
+  <p>
+  A writeable iterator isn't provided because:  The number of bytes of the old
+  UTF-8 character and the new one to write could be different. Therefore, any
+  write operation would invalidate all other iterators pointing into the same
+  string.
+*/
+template <class T>
+class ustring_Iterator
+{
+public:
+  typedef std::bidirectional_iterator_tag   iterator_category;
+  typedef unichar                           value_type;
+  typedef std::string::difference_type      difference_type;
+  typedef value_type                        reference;
+  typedef void                              pointer;
+
+  inline ustring_Iterator() {}
+  inline ustring_Iterator(const ustring_Iterator<std::string::iterator>&
+			  other) : _pos(other.base()) {}
+
+  inline value_type operator*() const {
+    // get a unicode character from the iterator's position
+
+    // get an iterator to the internal string
+    std::string::const_iterator pos = _pos;
+    
+    unichar result = static_cast<unsigned char>(*pos);
+
+    // if its not a 7-bit ascii character
+    if((result & 0x80) != 0) {
+      // len is the number of bytes this character takes up in the string
+      unsigned char len = g_utf8_skip[result];
+      result &= 0x7F >> len;
+      
+      while(--len != 0) {
+	result <<= 6;
+	result |= static_cast<unsigned char>(*++pos) & 0x3F;
+      }
+    }
+    
+    return result;
+  }
+
+  inline ustring_Iterator<T> &     operator++() {
+    pos_ += g_utf8_skip[static_cast<unsigned char>(*pos_)];
+    return *this;
+  }
+  inline ustring_Iterator<T> &     operator--() {
+    do { --_pos; } while((*_pos & '\xC0') == '\x80');
+    return *this;
+  }
+
+  explicit inline ustring_Iterator(T pos) : _pos(pos) {}
+  inline T base() const { return _pos; }
+
+private:
+  T _pos;
+};
+
+//! This class provides a simple wrapper to a std::string that is encoded as
+//! UTF-8.
+/*!
+  This class does <b>not</b> handle extended 8-bit ASCII charsets like
+  ISO-8859-1.
+  <p>
+  More info on Unicode and UTF-8 can be found here:
+  http://www.cl.cam.ac.uk/~mgk25/unicode.html
+  <p>
+  This does not subclass std::string, because std::string was intended to be a
+  final class.  For instance, it does not have a virtual destructor.
+*/
+class ustring {
+  std::string _string;
+
+public:
+  typedef std::string::size_type                        size_type;
+  typedef std::string::difference_type                  difference_type;
+
+  typedef unichar                                       value_type;
+  typedef unichar &                                     reference;
+  typedef const unichar &                               const_reference;
+
+  typedef ustring_Iterator<std::string::iterator>       iterator;
+  typedef ustring_Iterator<std::string::const_iterator> const_iterator;
+
+  static const size_type npos = std::string::npos;
+
+  ustring();
+  ~ustring();
+
+  // make new strings
+  
+  ustring(const ustring& other);
+  ustring& operator=(const ustring& other);
+  ustring(const std::string& src);
+  ustring::ustring(const char* src);
+
+  
+};
+
+}
+
+#endif // __ustring_hh