xmlXPathError

type xmlXPathError = (

  XPATH_EXPRESSION_OK = 0,

  XPATH_NUMBER_ERROR,

  XPATH_UNFINISHED_LITERAL_ERROR,

  XPATH_START_LITERAL_ERROR,

  XPATH_VARIABLE_REF_ERROR,

  XPATH_UNDEF_VARIABLE_ERROR,

  XPATH_INVALID_PREDICATE_ERROR,

  XPATH_EXPR_ERROR,

  XPATH_UNCLOSED_ERROR,

  XPATH_UNKNOWN_FUNC_ERROR,

  XPATH_INVALID_OPERAND,

  XPATH_INVALID_TYPE,

  XPATH_INVALID_ARITY,

  XPATH_INVALID_CTXT_SIZE,

  XPATH_INVALID_CTXT_POSITION,

  XPATH_MEMORY_ERROR,

  XPTR_SYNTAX_ERROR,

  XPTR_RESOURCE_ERROR,

  XPTR_SUB_RESOURCE_ERROR,

  XPATH_UNDEF_PREFIX_ERROR,

  XPATH_ENCODING_ERROR,

  XPATH_INVALID_CHAR_ERROR,

  XPATH_INVALID_CTXT

);