Index: library/mongodb/nx-mongo.tcl
===================================================================
diff -u -r4028b984af21ce2b0232ed8cb46572dc8336c76b -r788f2f577d21a28e0d6a05ca87562a507d929527
--- library/mongodb/nx-mongo.tcl	(.../nx-mongo.tcl)	(revision 4028b984af21ce2b0232ed8cb46572dc8336c76b)
+++ library/mongodb/nx-mongo.tcl	(.../nx-mongo.tcl)	(revision 788f2f577d21a28e0d6a05ca87562a507d929527)
@@ -454,6 +454,11 @@
 	  "in" - "all" {
 	    lappend bson $att document [list [:get relop $op] {*}[$slot bson encode -array $value]]
 	  }
+          "~" {
+            # value should be a two-element list contain pattern and options
+	    lappend bson $att document [list {$regex} regex $value]
+	  }
+
 	  default {return -code error "unknown operator $op"}
 	}
       }
Index: library/mongodb/tests/nx-mongo.test
===================================================================
diff -u -rab21c8502870e715c567c657146283699e31b01b -r788f2f577d21a28e0d6a05ca87562a507d929527
--- library/mongodb/tests/nx-mongo.test	(.../nx-mongo.test)	(revision ab21c8502870e715c567c657146283699e31b01b)
+++ library/mongodb/tests/nx-mongo.test	(.../nx-mongo.test)	(revision 788f2f577d21a28e0d6a05ca87562a507d929527)
@@ -115,6 +115,9 @@
 ? {llength [set persons [Person find all -cond {age > 30}]]} 1
 ? {lsort [lmap p $persons {$p cget -name}]} "Gustaf"
 
+puts "\nFind persons with names matching regular expression /an/i  (containing 'an', ignore case):"
+? {llength [set persons [Person find all -cond {name ~ {an i}}]]} 2
+? {lsort [lmap p $persons {$p cget -name}]} "Franz Stefan"
 
 #
 # Define a special find method for "Person" named "oldies" by
@@ -124,6 +127,7 @@
   return [:find all -cond {age > 30}]
 }
 
+
 #
 # Use the special find method
 #