func readRune(r io.RuneScanner) int {
rune, _, err := r.ReadRune()
if err != nil {
return -1
}
return rune
}
// like in.ReadRune() but ignore all leading whitespace.
func ReadChar(in io.RuneScanner) (r rune, size int, err error) {
r, size, err = in.ReadRune()
for unicode.IsSpace(r) && err == nil {
r, size, err = in.ReadRune()
}
return
}
// ParseDelimited returns the string
// up to the first unescaped delimiter,
// raw newline (rune 0xA),
// or the end of input.
// A delimiter preceeded by \ is escaped and is non-terminating.
// The letter n preceeded by \ is a newline literal.
func parseDelimited(delim rune, rs io.RuneScanner) (string, error) {
var s string
var esc bool
for {
switch r, _, err := rs.ReadRune(); {
case err == io.EOF:
return s, nil
case err != nil:
return "", err
case esc && r == delim:
s += string(delim)
esc = false
case r == delim || r == '\n':
return s, nil
case !esc && r == '\\':
esc = true
case esc && r == 'n':
s += "\n"
esc = false
default:
if esc {
s += "\\"
}
s += string(r)
esc = false
}
}
}
// readSDElement reads an SD-ELEMENT as defined by RFC-5424
//
// SD-ELEMENT = "[" SD-ID *(SP SD-PARAM) "]"
// SD-PARAM = PARAM-NAME "=" %d34 PARAM-VALUE %d34
// SD-ID = SD-NAME
// PARAM-NAME = SD-NAME
// PARAM-VALUE = UTF-8-STRING ; characters '"', '\' and ']' MUST be escaped.
// SD-NAME = 1*32PRINTUSASCII except '=', SP, ']', %d34 (")
func readSDElement(r io.RuneScanner) (element StructuredData, err error) {
ch, _, err := r.ReadRune()
if err != nil {
return element, err // hard to reach without underlying IO error
}
if ch != '[' {
return element, BadFormat("StructuredData[]") // unreachable
}
element.ID, err = readSdID(r)
if err != nil {
return element, err
}
for {
ch, _, err := r.ReadRune()
if err != nil {
return element, err
} else if ch == ']' {
return element, nil
} else if ch == ' ' {
param, err := readSdParam(r)
if err != nil {
return element, err
}
element.Parameters = append(element.Parameters, *param)
} else {
return element, BadFormat("StructuredData[]")
}
}
}
// readStructuredData reads a STRUCTURED-DATA (as defined in RFC-5424)
// from `r` and assigns the StructuredData member.
//
// STRUCTURED-DATA = NILVALUE / 1*SD-ELEMENT
// SD-ELEMENT = "[" SD-ID *(SP SD-PARAM) "]"
// SD-PARAM = PARAM-NAME "=" %d34 PARAM-VALUE %d34
// SD-ID = SD-NAME
// PARAM-NAME = SD-NAME
// PARAM-VALUE = UTF-8-STRING ; characters '"', '\' and ']' MUST be escaped.
// SD-NAME = 1*32PRINTUSASCII except '=', SP, ']', %d34 (")
func (m *Message) readStructuredData(r io.RuneScanner) (err error) {
m.StructuredData = []StructuredData{}
ch, _, err := r.ReadRune()
if err != nil {
return err
}
if ch == '-' {
return nil
}
r.UnreadRune()
for {
ch, _, err := r.ReadRune()
if err == io.EOF {
return nil
} else if err != nil {
return err // hard to reach without underlying IO error
} else if ch == ' ' {
r.UnreadRune()
return nil
} else if ch == '[' {
r.UnreadRune()
sde, err := readSDElement(r)
if err != nil {
return err
}
m.StructuredData = append(m.StructuredData, sde)
} else {
return BadFormat("StructuredData")
}
}
}
// readPriority reads the PRI as defined in RFC-5424 and assigns Severity and
// Facility accordingly.
func (m *Message) readPriority(r io.RuneScanner) error {
ch, _, err := r.ReadRune()
if err != nil {
return err
}
if ch != '<' {
return BadFormat("Priority")
}
rv := &bytes.Buffer{}
for {
ch, _, err := r.ReadRune()
if err != nil {
return err
}
if unicode.IsDigit(ch) {
rv.WriteRune(ch)
continue
}
if ch != '>' {
return BadFormat("Priority")
}
// We have a complete integer expression
priority, err := strconv.ParseInt(string(rv.Bytes()), 10, 32)
if err != nil {
return BadFormat("Priority")
}
m.Priority = int(priority)
return nil
}
}
// ParseNumber parses and returns a positive integer.
// Leading spaces are ignored.
// If EOF is reached before any digits are encountered, 1 is returned.
func parseNumber(rs io.RuneScanner) (int, error) {
if err := skipSpace(rs); err != nil {
return 0, err
}
var s string
for {
switch r, _, err := rs.ReadRune(); {
case err == io.EOF:
break
case err != nil:
return 0, err
case unicode.IsDigit(r):
s += string(r)
continue
default:
if err := rs.UnreadRune(); err != nil {
return 0, err
}
}
if len(s) == 0 {
return 1, nil
}
return strconv.Atoi(s)
}
}
func parseCmd(rs io.RuneScanner) (string, error) {
if err := skipSpace(rs); err != nil {
return "", err
}
var esc bool
var cmd string
for {
switch r, _, err := rs.ReadRune(); {
case err == io.EOF:
return cmd, nil
case err != nil:
return "", nil
case r == '\n':
return cmd, nil
case r == '\\':
esc = true
case esc && r == 'n':
cmd += "\n"
esc = false
default:
if esc {
cmd += "\\"
}
cmd += string(r)
esc = false
}
}
}
// readSpace reads a single space
func readSpace(r io.RuneScanner) error {
ch, _, err := r.ReadRune()
if err != nil {
return err
}
if ch != ' ' {
return BadFormat("expected space")
}
return nil
}
// readVersion reads the version string fails if it isn't `1`
func (m *Message) readVersion(r io.RuneScanner) error {
ch, _, err := r.ReadRune()
if err != nil {
return err
}
if ch != '1' {
return BadFormat("Version")
}
return nil
}
func chompBOM(r io.RuneScanner) (err error) {
for {
c, _, err := r.ReadRune()
if err != nil {
return err
}
if c != BOM {
r.UnreadRune()
return nil
}
}
}
func chompWhitespace(r io.RuneScanner) (err error) {
for {
c, _, err := r.ReadRune()
if err != nil {
return err
}
if !unicode.IsSpace(c) {
r.UnreadRune()
return nil
}
}
}
func skipSingleNewline(rs io.RuneScanner) error {
// Eat a single trailing newline.
switch r, _, err := rs.ReadRune(); {
case err == io.EOF:
return nil
case err != nil:
return err
case r == '\n':
return nil
default:
return rs.UnreadRune()
}
}
func (d *Dec) scan(r io.RuneScanner) error {
d.coef.hi = 0
d.coef.lo = 0
d.scale = 0
ch, _, err := r.ReadRune()
if err != nil {
return err
}
var neg bool
switch ch {
case '-':
neg = true
case '+':
default:
r.UnreadRune()
}
var dec bool
for {
ch, _, err = r.ReadRune()
if err == io.EOF {
goto ExitLoop
}
if err != nil {
return err
}
switch {
case ch == '.':
if dec {
r.UnreadRune()
goto ExitLoop
}
dec = true
case ch >= '0' && ch <= '9':
d.coef.Mul(&d.coef, intTen)
var z Int128
z.SetInt64(int64(ch - '0'))
d.coef.Add(&d.coef, &z)
if dec {
d.scale++
}
default:
r.UnreadRune()
goto ExitLoop
}
}
ExitLoop:
if neg {
d.Neg(d)
}
return nil
}
func parseMarkRune(rs io.RuneScanner) (rune, error) {
for {
switch r, _, err := rs.ReadRune(); {
case err == io.EOF:
return '.', nil
case err != nil:
return 0, err
case unicode.IsSpace(r):
continue
default:
return r, nil
}
}
}
// readSdParam reads a PARAM-NAME as defined by RFC-5424
// SD-PARAM = PARAM-NAME "=" %d34 PARAM-VALUE %d34
// PARAM-NAME = SD-NAME
// SD-NAME = 1*32PRINTUSASCII except '=', SP, ']', %d34 (")
func readSdParamName(r io.RuneScanner) (string, error) {
rv := &bytes.Buffer{}
for {
ch, _, err := r.ReadRune()
if err != nil {
return "", err
}
if ch == '=' {
r.UnreadRune()
return string(rv.Bytes()), nil
}
rv.WriteRune(ch)
}
}
func readNumber(b int, r io.RuneScanner) interface{} {
s := string(b)
for {
rune := readRune(r)
if rune == -1 || isWhiteSpace(rune) || rune == ')' {
r.UnreadRune()
return s
}
s = s + string(rune)
}
return matchNumer(s)
}
func stringReader(flag int, r io.RuneScanner) interface{} {
var s string = ""
for {
rune, _, err := r.ReadRune()
if err != nil {
panic("err")
}
if rune == '"' {
return s
}
s = s + string(rune)
}
return s
}
func parseNegation(r io.RuneScanner, glob *globImpl) error {
for {
char, _, err := r.ReadRune()
if err != nil {
return err
} else if char == '!' {
glob.negated = !glob.negated
} else {
r.UnreadRune()
return nil
}
}
}
// SkipSpace consumes and ignores non-newline whitespace.
// Terminates if a newline is encountered.
// The terminating newline remains consumed.
func skipSpace(rs io.RuneScanner) error {
for {
switch r, _, err := rs.ReadRune(); {
case err == io.EOF:
return nil
case err != nil:
return err
case r != '\n' && unicode.IsSpace(r):
continue
default:
return rs.UnreadRune()
}
}
}
func scanDigits(rs io.RuneScanner) (string, error) {
var s string
for {
switch r, _, err := rs.ReadRune(); {
case err == io.EOF:
return s, nil
case err != nil:
return "", err
case !unicode.IsDigit(r):
return s, rs.UnreadRune()
default:
s += string(r)
}
}
}
func parseMarkAddr(rs io.RuneScanner) (SimpleAddress, error) {
for {
switch r, _, err := rs.ReadRune(); {
case err == io.EOF:
return nil, errors.New("bad mark: EOF")
case err != nil:
return nil, err
case !unicode.IsSpace(r) || r == '\n':
if !isMarkRune(r) {
return nil, errors.New("bad mark: " + string(r))
}
return Mark(r), nil
}
}
}
func parseText(rs io.RuneScanner) (string, error) {
for {
switch r, _, err := rs.ReadRune(); {
case err == io.EOF:
return "", nil
case err != nil:
return "", err
case r == '\n':
return parseLines(rs)
case unicode.IsSpace(r):
continue
default:
return parseDelimited(r, rs)
}
}
}
func parseLines(rs io.RuneScanner) (string, error) {
var s string
var nl bool
for {
switch r, _, err := rs.ReadRune(); {
case err == io.EOF:
return s, nil
case err != nil:
return "", err
case nl && r == '.':
return s, nil
default:
s += string(r)
nl = r == '\n'
}
}
}
// ScanBareIdent reads bare identifier from a rune reader.
func ScanBareIdent(r io.RuneScanner) string {
// Read every ident character into the buffer.
// Non-ident characters and EOF will cause the loop to exit.
var buf bytes.Buffer
for {
ch, _, err := r.ReadRune()
if err != nil {
break
} else if !isIdentChar(ch) {
r.UnreadRune()
break
} else {
_, _ = buf.WriteRune(ch)
}
}
return buf.String()
}
// readWord reads `r` until it encounters a space (0x20)
func readWord(r io.RuneScanner) (string, error) {
rv := &bytes.Buffer{}
for {
ch, _, err := r.ReadRune()
if err != nil {
return "", err
} else if ch != ' ' {
rv.WriteRune(ch)
} else {
r.UnreadRune()
rvString := string(rv.Bytes())
if rvString == "-" {
rvString = ""
}
return rvString, nil
}
}
}
// readSdParam reads an SD-PARAM as defined by RFC-5424
// SD-PARAM = PARAM-NAME "=" %d34 PARAM-VALUE %d34
// SD-ID = SD-NAME
// PARAM-NAME = SD-NAME
// PARAM-VALUE = UTF-8-STRING ; characters '"', '\' and ']' MUST be escaped.
// SD-NAME = 1*32PRINTUSASCII except '=', SP, ']', %d34 (")
func readSdParam(r io.RuneScanner) (sdp *SDParam, err error) {
sdp = &SDParam{}
sdp.Name, err = readSdParamName(r)
if err != nil {
return nil, err
}
ch, _, err := r.ReadRune()
if err != nil {
return nil, err // hard to reach
}
if ch != '=' {
return nil, BadFormat("StructuredData[].Parameters") // not reachable
}
sdp.Value, err = readSdParamValue(r)
if err != nil {
return nil, err
}
return sdp, nil
}
func ReadList(in io.RuneScanner) Sexper {
ch, _, _ := ReadChar(in)
chstr := string(ch)
switch chstr {
case ")":
return NIL
case ".":
list := ReadList(in)
if list == NIL || fn_cdr(list) != NIL {
panic(ERROR_DOT)
}
return fn_car(list)
default:
in.UnreadRune()
scar := ReadSexp(in)
scdr := ReadList(in)
return List{scar, scdr}
}
}
// scanEscapeCommand scans to the end of the current escape sequence. The scanner
// must be positioned at an escape rune (esc or the unicode CSI).
func scanEscapeCommand(s io.RuneScanner) (Command, error) {
csi := false
esc, _, err := s.ReadRune()
if err != nil {
return nil, err
}
if esc != escape && esc != monogramCsi {
panic(fmt.Errorf("not positioned at beginning of escape sequence, saw: %v", esc))
}
if esc == monogramCsi {
csi = true
}
var args bytes.Buffer
quote := false
for i := 0; ; i++ {
r, _, err := s.ReadRune()
if err != nil {
return nil, err
}
if i == 0 && r == '[' {
csi = true
continue
}
if !csi {
return escapeCommand{r, ""}, nil
} else if quote == false && unicode.Is(csEnd, r) {
return escapeCommand{r, args.String()}, nil
}
if r == '"' {
quote = !quote
}
// Otherwise, we're still in the args, and this rune is one of those args.
if _, err := args.WriteRune(r); err != nil {
panic(err) // WriteRune cannot return an error from bytes.Buffer.
}
}
}
func ReadSexp(in io.RuneScanner) Sexper {
ch, _, _ := ReadChar(in)
switch string(ch) {
case "\"":
return ReadString(in)
case "(":
return ReadList(in)
case "'":
return fn_cons(Atom{"quote"}, fn_cons(ReadSexp(in), NIL))
case ")":
panic("unexcepted ')' found")
default:
in.UnreadRune()
if unicode.IsDigit(ch) {
return ReadNumber(in)
} else {
return ReadAtom(in)
}
}
}
