diff -r 000000000000 -r 6f7a81934006 lib/mystring/sub.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/mystring/sub.cc	Wed Jan 16 22:39:43 2008 +0100
@@ -0,0 +1,37 @@
+#include "mystring.h"
+
+// return the sub-string ending at 'offset'
+mystring mystring::left(size_t offset) const
+{
+  if(offset > rep->length)
+    return *this;
+  else
+    return mystring(rep->buf, offset);
+}
+
+// return the sub-string starting at 'offset'
+mystring mystring::right(size_t offset) const
+{
+  if(offset >= rep->length)
+    return mystring();
+  else if(offset == 0)
+    return *this;
+  else
+    return mystring(rep->buf+offset, rep->length-offset);
+}
+
+// return the 'len' characters of the string starting at 'offset'
+mystring mystring::sub(size_t offset, size_t len) const
+{
+  // return right(offset).left(len);
+  if(len == 0)
+    return mystring();
+  else if(offset == 0 && len >= rep->length)
+    return *this;
+  else {
+    if(len+offset >= rep->length)
+      len = rep->length - offset;
+    return mystring(rep->buf+offset, len);
+  }
+}
+