use G;                          # Imports G-language GAE module 
   
 $gb = new G("ecoli.gbk");       # Creates G's instance as $gb 
 $gb =  load("ecoli.gbk");       # this line is same as the above.
                                 # At the same time, read in ecoli.gbk. 
                                 # Read the annotation and sequence 
                                 # information 
                                 # See DESCRIPTION for details
   
 $gb->seq_info();                # Prints the basic sequence information.

 find_ori_ter($gb);              # Give $gb as the first argument to 
                                 # most of the analysis functions

 The G-language GAE fully supports most sequence databases.

 Stored annotation information:

 LOCUS  
         $gb->{LOCUS}->{id}              -accession number 
         $gb->{LOCUS}->{length}          -length of sequence  
         $gb->{LOCUS}->{nucleotide}      -type of sequence ex. DNA, RNA  
         $gb->{LOCUS}->{circular}        -1 when the genome is circular.
                                          otherwise 0
         $gb->{LOCUS}->{type}            -type of species ex. BCT, CON  
         $gb->{LOCUS}->{date}            -date of accession 

 HEADER  
         $gb->{HEADER}  
         $gb->{DEFINITION}
         $gb->{ACCESSION}
         $gb->{SOURCE}
         $gb->{ORGANISM}

         $gb->{TAXONOMY}->{all}          -same as $gb->{TAXONOMY}->{1}
         $gb->{TAXONOMY}->{domain}       -same as $gb->{TAXONOMY}->{2}
         $gb->{TAXONOMY}->{phylum}       -same as $gb->{TAXONOMY}->{3}
         $gb->{TAXONOMY}->{class}        -same as $gb->{TAXONOMY}->{4}
         $gb->{TAXONOMY}->{order}}       -same as $gb->{TAXONOMY}->{5}
         $gb->{TAXONOMY}->{family}       -same as $gb->{TAXONOMY}->{6}
         $gb->{TAXONOMY}->{genus}
         $gb->{TAXONOMY}->{species}

 COMMENT  
         $gb->{COMMENT}  

 FEATURE  
         Each FEATURE is numbered(FEATURE1 .. FEATURE1172), and is a 
         hash structure that contains all the keys of Genbank.   
         In other words,  in most cases, FEATURE$i's hash at least 
         contains informations listed below: 
         $gb->{FEATURE$i}->{start}  
         $gb->{FEATURE$i}->{end}  
         $gb->{FEATURE$i}->{direction}
         $gb->{FEATURE$i}->{join}
         $gb->{FEATURE$i}->{note}  
         $gb->{FEATURE$i}->{type}        -CDS,gene,RNA,etc.
         $gb->{FEATURE$i}->{feature}     -same as $i

         To analyze each FEATURE, write: 

         foreach my $feature ($gb->feature()){
               print $gb->{$feature}->{type}, "\n";
         }  

         In the same manner, to analyze all CDS, write:  
 
         foreach my $cds ($gb->cds()){
               print $gb->{$cds}->{gene}, "\n";
         }

         Feature or gene information can also be accessed with CDS numbers:
         $gb->{CDS$i}->{start}

         or with locus_tags or gene names (for CDS, tRNA, and rRNA)
         $gb->{thrL}->{start}
         $gb->{b0001}->{start}

 BASE COUNT  
         $gb->{BASE_COUNT}  

 SEQ  
         $gb->{SEQ}              -sequence data following "ORIGIN" 

         or
 
         $gb->seq()

    return new G(@_);

    my $opt = shift;
    my %system;

    for my $name (qw/
		  p puts say readFile writeFile 
		  opt_as_gb opt_default opt_get opt_list opt_val
		  msg_ask_interface msg_error msg_send msg_gimv msg_interface msg_percent msg_progress msg_set_gimv msg_system_console msg_term_console
		  sdb_exists sdb_load sdb_save _sdb_path _set_sdb_path
		  db_dbi db_exists db_load db_path db_save db_set_path
		  pass_send pass_get
		  /){
	$system{$name} ++;

    my $sub = shift;

    SubOpt::opt_default();
    SubOpt::set_opt_list(1);
    eval("&{$sub}");
    SubOpt::set_opt_list(0);

    return opt_val();

     Name: $gb = new G("genome file")   -   create a G instance

     see "help load" for more information.

   Name: $gb->next_locus()   -   read the next locus and update the G instance

   Description:
         Reads the next locus.
         the G instance is then updated. 
         Load G instance with "no cache" option to use this feature.

         eg. 
           do{
  
           }while($gb->next_locus());
           #  Enables multiple loci analysis.        

   REST: 
      http://rest.g-language.org/NC_000913/next_locus