xmlTypeIndex -- get XML type code from its description

i1 : xmlTypeIndex

o1 = HashTable{attribute decl => 16    }
               attribute node => 2
               cdata section node => 4
               comment node => 8
               document frag node => 11
               document node => 9
               document type node => 10
               dtd node => 14
               element decl => 15
               element node => 1
               entity decl => 17
               entity node => 6
               entity ref node => 5
               html document node => 13
               namespace decl => 18
               notation node => 12
               pi node => 7
               text node => 3
               xinclude end => 20
               xinclude start => 19

o1 : HashTable