add rsplit function

git-svn-id: http://pystring.googlecode.com/svn/trunk@3 e90ac086-db91-11dd-a3d5-f9b94b98161c

Author: PeterShinners

pystring.cpp

@@ -31,48 +31,99 @@
 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ///////////////////////////////////////////////////////////////////////////////
 
-#include <pystring.h>
 #include <ctype.h>
 #include <string.h>
 #include <iostream>
+#include <algorithm>
+#include "pystring.h"
 
 namespace pystring
 {
-    
-    //////////////////////////////////////////////////////////////////////////////////////////////
-    ///
-    ///
-    void split_whitespace( const std::string & str, std::vector< std::string > & result, int maxsplit )
-    {
-        std::string::size_type i, j, len = str.size();
-        for (i = j = 0; i < len; )
-        {
-            
-            while ( i < len && ::isspace( str[i] ) ) i++;
-            j = i;
-            
-            while ( i < len && ! ::isspace( str[i]) ) i++;
-            
-            
-            
-            if (j < i)
-            {
-                if ( maxsplit-- <= 0 ) break;
-                
-                result.push_back( str.substr( j, i - j ));
-                
-                while ( i < len && ::isspace( str[i])) i++;
-                j = i;
-            }
-        }
-        if (j < len)
-        {
-            
-            result.push_back( str.substr( j, len - j ));
-        }
-    }
-    
-    
+
+	namespace {
+
+		//////////////////////////////////////////////////////////////////////////////////////////////
+		/// why doesn't the std::reverse work?
+		///
+		void reverse_strings( std::vector< std::string > & result)
+		{
+			for (std::vector< std::string >::size_type i = 0; i < result.size() / 2; i++ )
+			{
+				std::swap(result[i], result[result.size() - 1 - i]);
+			}
+		}
+
+		//////////////////////////////////////////////////////////////////////////////////////////////
+		///
+		///
+		void split_whitespace( const std::string & str, std::vector< std::string > & result, int maxsplit )
+		{
+			std::string::size_type i, j, len = str.size();
+			for (i = j = 0; i < len; )
+			{
+
+				while ( i < len && ::isspace( str[i] ) ) i++;
+				j = i;
+
+				while ( i < len && ! ::isspace( str[i]) ) i++;
+
+
+
+				if (j < i)
+				{
+					if ( maxsplit-- <= 0 ) break;
+
+					result.push_back( str.substr( j, i - j ));
+
+					while ( i < len && ::isspace( str[i])) i++;
+					j = i;
+				}
+			}
+			if (j < len)
+			{
+				result.push_back( str.substr( j, len - j ));
+			}
+		}
+
+
+		//////////////////////////////////////////////////////////////////////////////////////////////
+		///
+		///
+		void rsplit_whitespace( const std::string & str, std::vector< std::string > & result, int maxsplit )
+		{
+			std::string::size_type len = str.size();
+			std::string::size_type i, j;
+			for (i = j = len; i > 0; )
+			{
+
+				while ( i > 0 && ::isspace( str[i - 1] ) ) i--;
+				j = i;
+
+				while ( i > 0 && ! ::isspace( str[i - 1]) ) i--;
+
+
+
+				if (j > i)
+				{
+					if ( maxsplit-- <= 0 ) break;
+
+					result.push_back( str.substr( i, j - i ));
+
+					while ( i > 0 && ::isspace( str[i - 1])) i--;
+					j = i;
+				}
+			}
+			if (j > 0)
+			{
+				result.push_back( str.substr( 0, j ));
+			}
+			//std::reverse( result, result.begin(), result.end() );
+			reverse_strings( result );
+		}
+
+	} //anonymous namespace
+
+
     //////////////////////////////////////////////////////////////////////////////////////////////
     ///
     ///
@@ -111,6 +162,51 @@ namespace pystring
         result.push_back( str.substr( j, len-j ) );
     }
 
+    //////////////////////////////////////////////////////////////////////////////////////////////
+    ///
+    ///
+    void rsplit( const std::string & str, std::vector< std::string > & result, const std::string & sep, int maxsplit )
+    {
+		if ( maxsplit == 0 )
+		{
+			split( str, result, sep, 0 );
+			return;
+		}
+
+        result.clear();
+
+        if ( maxsplit < 0 ) maxsplit = MAX_32BIT_INT;//result.max_size();
+
+
+        if ( sep.size() == 0 )
+        {
+            rsplit_whitespace( str, result, maxsplit );
+            return;
+        }
+
+        std::string::size_type i,j, len = str.size(), n = sep.size();
+
+        i = j = len;
+
+        while ( i > n )
+        {
+            if ( str[i - 1] == sep[n - 1] && str.substr( i - n, n ) == sep )
+            {
+                if ( maxsplit-- <= 0 ) break;
+
+                result.push_back( str.substr( i, j - i ) );
+                i = j = i - n;
+            }
+            else
+            {
+                i--;
+            }
+        }
+
+        result.push_back( str.substr( 0, j ) );
+        reverse_strings( result );
+    }
+
     //////////////////////////////////////////////////////////////////////////////////////////////
     ///
     ///

pystring.h

@@ -203,7 +203,16 @@ namespace pystring
     /// any whitespace string is a separator.
     ///
     void split( const std::string & str, std::vector< std::string > & result, const std::string & sep = "", int maxsplit = -1);
-    
+	
+    //////////////////////////////////////////////////////////////////////////////////////////////
+    /// @brief Fills the "result" list with the words in the string, using sep as the delimiter string.
+    /// Does a number of splits starting at the end of the string, the result still has the
+    /// split strings in their original order.
+    /// If maxsplit is > -1, at most maxsplit splits are done. If sep is "",
+    /// any whitespace string is a separator.
+    ///
+    void rsplit( const std::string & str, std::vector< std::string > & result, const std::string & sep = "", int maxsplit = -1);
+	
     //////////////////////////////////////////////////////////////////////////////////////////////
     /// @brief Return a list of the lines in the string, breaking at line boundaries. Line breaks
     /// are not included in the resulting list unless keepends is given and true.