func (st *ST) Empty() bool {
	return st == nil || *st == ""
}
Empty returns whether ST is nil or empty.
package hl7
import (
	"bytes"
	"errors"
	"reflect"
	"strconv"
	"time"
	"golang.org/x/text/encoding/unicode"
)
type ST string
var _ Primitive = (*ST)(nil)
func NewST(st ST) *ST {
	return &st
}
func (st *ST) Marshal(_ *Context) ([]byte, error) {
	return []byte(string(*st)), nil
}
func (st *ST) Unmarshal(field []byte, c *Context) error {
	parsed, err := parseText(field, c)
	if err != nil {
		*st = ""
		return err
	}
	*st = ST(parsed)
	return nil
}
func SanitizeString(s string) string {
	if isHL7Null([]byte(s)) {
		return ""
	}
	return s
}
func (st *ST) SanitizedString() string {
	return SanitizeString(st.String())
}
func (st *ST) String() string {
	if st == nil {
		return ""
	}
	return string(*st)
}