Segment.rb in X12-0.1.0

- old
+ new

@@ -21,11 +21,11 @@
 #     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 #++
 #
 module X12
 
-  # $Id: Segment.rb 35 2008-11-13 18:33:44Z ikk $
+  # $Id: Segment.rb 54 2009-03-18 17:04:45Z ikk $
   #
   # Implements a segment containing fields or composites
     
   class Segment < Base
 
@@ -63,10 +63,23 @@
       }
     end # render
 
     # Returns a regexp that matches this particular segment
     def regexp
-      @regexp ||= Regexp.new("^#{name}#{Regexp.escape(field_separator)}[^#{Regexp.escape(segment_separator)}]*#{Regexp.escape(segment_separator)}")
+      unless @regexp
+        if self.nodes.find{|i| i.type =~ /^".+"$/ }
+          # It's a very special regexp if there are constant fields
+          re_str = self.nodes.inject("^#{name}#{Regexp.escape(field_separator)}"){|s, i|
+            s+i.str_regexp(field_separator)+Regexp.escape(field_separator)
+          } + '?'+Regexp.escape(segment_separator)
+          @regexp = Regexp.new(re_str)
+        else
+          # Simple match
+          @regexp = Regexp.new("^#{name}#{Regexp.escape(field_separator)}[^#{Regexp.escape(segment_separator)}]*#{Regexp.escape(segment_separator)}")
+        end
+        #puts @regexp
+      end
+      @regexp
     end
 
     # Finds a field in the segment. Returns EMPTY if not found.
     def find_field(str)
       #puts "Finding field [#{str}] in #{self.class} #{name}"