type xml = | Element of string * (string * string) list * xml list| PCData of string
type error_msg = | UnterminatedString| UnterminatedEntity| IdentExpected| CloseExpected| NodeExpected| AttributeNameExpected| AttributeValueExpected| EndOfTagExpected of string| EOFExpected
type error_pos = {eline : int;eline_start : int;emin : int;emax : int;
}type dtd_element_type = | DTDEmpty| DTDAny| DTDChild of dtd_child
type dtd_attr_default = | DTDDefault of string| DTDRequired| DTDImplied| DTDFixed of string
type dtd_attr_type = | DTDCData| DTDNMToken| DTDEnum of string list| DTDID| DTDIDRef