Initial boost-regex++ release

[SVN r7845]

src/primary_transform.hpp

@@ -0,0 +1,118 @@
+/*
+ *
+ * Copyright (c) 1998-2000
+ * Dr John Maddock
+ *
+ * Permission to use, copy, modify, distribute and sell this software
+ * and its documentation for any purpose is hereby granted without fee,
+ * provided that the above copyright notice appear in all copies and
+ * that both that copyright notice and this permission notice appear
+ * in supporting documentation.  Dr John Maddock makes no representations
+ * about the suitability of this software for any purpose.  
+ * It is provided "as is" without express or implied warranty.
+ *
+ */
+ 
+ /*
+  *   LOCATION:    see http://www.boost.org for most recent version.
+  *   FILE:        primary_transform.hpp
+  *   VERSION:     3.00
+  *   DESCRIPTION: Heuristically determines the sort string format in use
+  *                by the current locale.
+  */
+
+namespace boost{
+   namespace re_detail{
+
+
+enum{
+   sort_C,
+   sort_fixed,
+   sort_delim,
+   sort_unknown
+};
+
+template <class S, class charT>
+unsigned count_chars(const S& s, charT c)
+{
+   unsigned int count = 0;
+   for(unsigned pos = 0; pos <= s.size(); ++pos)
+   {
+      if(s[pos] == c) ++count;
+   }
+   return count;
+}
+
+
+template <class traits, class charT>
+unsigned find_sort_syntax(const traits* pt, charT* delim)
+{
+   //
+   // compare 'a' with 'A' to see how similar they are,
+   // should really use a-accute but we can't portably do that,
+   //
+   typedef typename traits::string_type string_type;
+   typedef typename traits::char_type char_type;
+
+   // Suppress incorrect warning for MSVC
+   (void)pt;
+
+   string_type a(1, (char_type)'a');
+   string_type sa;
+   pt->transform(sa, a);
+   if(sa == a)
+   {
+      *delim = 0;
+      return sort_C;
+   }
+   string_type A(1, (char_type)'A');
+   string_type sA;
+   pt->transform(sA, A);
+   string_type c(1, (char_type)';');
+   string_type sc;
+   pt->transform(sc, c);
+
+   int pos = 0;
+   while((pos <= static_cast<int>(sa.size())) && (pos <= static_cast<int>(sA.size())) && (sa[pos] == sA[pos])) ++pos;
+   --pos;
+   if(pos < 0)
+   {
+      *delim = 0;
+      return sort_unknown;
+   }
+   //
+   // at this point sa[pos] is either the end of a fixed with field
+   // or the character that acts as a delimiter:
+   //
+   charT maybe_delim = sa[pos];
+   if((pos != 0) && (count_chars(sa, maybe_delim) == count_chars(sA, maybe_delim)) && (count_chars(sa, maybe_delim) == count_chars(c, maybe_delim)))
+   {
+      *delim = maybe_delim;
+      return sort_delim;
+   }
+   //
+   // OK doen't look like a delimiter, try for fixed width field:
+   //
+   if((sa.size() == sA.size()) && (sa.size() == c.size()))
+   {
+      // note assumes that the fixed width field is less than
+      // numeric_limits<charT>::max(), should be true for all types
+      // I can't imagine 127 character fields...
+      *delim = static_cast<charT>(++pos);
+      return sort_fixed;
+   }
+   //
+   // don't know what it is:
+   //
+   *delim = 0;
+   return sort_unknown;
+}
+
+
+   } // namespace re_detail
+} // namespace boost
+
+
+
+
+