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package toml
func scanFollows(b []byte, pattern string) bool {
n := len(pattern)
return len(b) >= n && string(b[:n]) == pattern
}
func scanFollowsMultilineBasicStringDelimiter(b []byte) bool {
return scanFollows(b, `"""`)
}
func scanFollowsMultilineLiteralStringDelimiter(b []byte) bool {
return scanFollows(b, `'''`)
}
func scanFollowsTrue(b []byte) bool {
return scanFollows(b, `true`)
}
func scanFollowsFalse(b []byte) bool {
return scanFollows(b, `false`)
}
func scanFollowsInf(b []byte) bool {
return scanFollows(b, `inf`)
}
func scanFollowsNan(b []byte) bool {
return scanFollows(b, `nan`)
}
func scanUnquotedKey(b []byte) ([]byte, []byte) {
// unquoted-key = 1*( ALPHA / DIGIT / %x2D / %x5F ) ; A-Z / a-z / 0-9 / - / _
for i := 0; i < len(b); i++ {
if !isUnquotedKeyChar(b[i]) {
return b[:i], b[i:]
}
}
return b, b[len(b):]
}
func isUnquotedKeyChar(r byte) bool {
return (r >= 'A' && r <= 'Z') || (r >= 'a' && r <= 'z') || (r >= '0' && r <= '9') || r == '-' || r == '_'
}
func scanLiteralString(b []byte) ([]byte, []byte, error) {
// literal-string = apostrophe *literal-char apostrophe
// apostrophe = %x27 ; ' apostrophe
// literal-char = %x09 / %x20-26 / %x28-7E / non-ascii
for i := 1; i < len(b); {
switch b[i] {
case '\'':
return b[:i+1], b[i+1:], nil
case '\n', '\r':
return nil, nil, newDecodeError(b[i:i+1], "literal strings cannot have new lines")
}
size := utf8ValidNext(b[i:])
if size == 0 {
return nil, nil, newDecodeError(b[i:i+1], "invalid character")
}
i += size
}
return nil, nil, newDecodeError(b[len(b):], "unterminated literal string")
}
func scanMultilineLiteralString(b []byte) ([]byte, []byte, error) {
// ml-literal-string = ml-literal-string-delim [ newline ] ml-literal-body
// ml-literal-string-delim
// ml-literal-string-delim = 3apostrophe
// ml-literal-body = *mll-content *( mll-quotes 1*mll-content ) [ mll-quotes ]
//
// mll-content = mll-char / newline
// mll-char = %x09 / %x20-26 / %x28-7E / non-ascii
// mll-quotes = 1*2apostrophe
for i := 3; i < len(b); {
switch b[i] {
case '\'':
if scanFollowsMultilineLiteralStringDelimiter(b[i:]) {
i += 3
// At that point we found 3 apostrophe, and i is the
// index of the byte after the third one. The scanner
// needs to be eager, because there can be an extra 2
// apostrophe that can be accepted at the end of the
// string.
if i >= len(b) || b[i] != '\'' {
return b[:i], b[i:], nil
}
i++
if i >= len(b) || b[i] != '\'' {
return b[:i], b[i:], nil
}
i++
if i < len(b) && b[i] == '\'' {
return nil, nil, newDecodeError(b[i-3:i+1], "''' not allowed in multiline literal string")
}
return b[:i], b[i:], nil
}
case '\r':
if len(b) < i+2 {
return nil, nil, newDecodeError(b[len(b):], `need a \n after \r`)
}
if b[i+1] != '\n' {
return nil, nil, newDecodeError(b[i:i+2], `need a \n after \r`)
}
i += 2 // skip the \n
continue
}
size := utf8ValidNext(b[i:])
if size == 0 {
return nil, nil, newDecodeError(b[i:i+1], "invalid character")
}
i += size
}
return nil, nil, newDecodeError(b[len(b):], `multiline literal string not terminated by '''`)
}
func scanWindowsNewline(b []byte) ([]byte, []byte, error) {
const lenCRLF = 2
if len(b) < lenCRLF {
return nil, nil, newDecodeError(b, "windows new line expected")
}
if b[1] != '\n' {
return nil, nil, newDecodeError(b, `windows new line should be \r\n`)
}
return b[:lenCRLF], b[lenCRLF:], nil
}
func scanWhitespace(b []byte) ([]byte, []byte) {
for i := 0; i < len(b); i++ {
switch b[i] {
case ' ', '\t':
continue
default:
return b[:i], b[i:]
}
}
return b, b[len(b):]
}
//nolint:unparam
func scanComment(b []byte) ([]byte, []byte, error) {
// comment-start-symbol = %x23 ; #
// non-ascii = %x80-D7FF / %xE000-10FFFF
// non-eol = %x09 / %x20-7F / non-ascii
//
// comment = comment-start-symbol *non-eol
for i := 1; i < len(b); {
if b[i] == '\n' {
return b[:i], b[i:], nil
}
if b[i] == '\r' {
if i+1 < len(b) && b[i+1] == '\n' {
return b[:i+1], b[i+1:], nil
}
return nil, nil, newDecodeError(b[i:i+1], "invalid character in comment")
}
size := utf8ValidNext(b[i:])
if size == 0 {
return nil, nil, newDecodeError(b[i:i+1], "invalid character in comment")
}
i += size
}
return b, b[len(b):], nil
}
func scanBasicString(b []byte) ([]byte, bool, []byte, error) {
// basic-string = quotation-mark *basic-char quotation-mark
// quotation-mark = %x22 ; "
// basic-char = basic-unescaped / escaped
// basic-unescaped = wschar / %x21 / %x23-5B / %x5D-7E / non-ascii
// escaped = escape escape-seq-char
escaped := false
i := 1
for ; i < len(b); i++ {
switch b[i] {
case '"':
return b[:i+1], escaped, b[i+1:], nil
case '\n', '\r':
return nil, escaped, nil, newDecodeError(b[i:i+1], "basic strings cannot have new lines")
case '\\':
if len(b) < i+2 {
return nil, escaped, nil, newDecodeError(b[i:i+1], "need a character after \\")
}
escaped = true
i++ // skip the next character
}
}
return nil, escaped, nil, newDecodeError(b[len(b):], `basic string not terminated by "`)
}
func scanMultilineBasicString(b []byte) ([]byte, bool, []byte, error) {
// ml-basic-string = ml-basic-string-delim [ newline ] ml-basic-body
// ml-basic-string-delim
// ml-basic-string-delim = 3quotation-mark
// ml-basic-body = *mlb-content *( mlb-quotes 1*mlb-content ) [ mlb-quotes ]
//
// mlb-content = mlb-char / newline / mlb-escaped-nl
// mlb-char = mlb-unescaped / escaped
// mlb-quotes = 1*2quotation-mark
// mlb-unescaped = wschar / %x21 / %x23-5B / %x5D-7E / non-ascii
// mlb-escaped-nl = escape ws newline *( wschar / newline )
escaped := false
i := 3
for ; i < len(b); i++ {
switch b[i] {
case '"':
if scanFollowsMultilineBasicStringDelimiter(b[i:]) {
i += 3
// At that point we found 3 apostrophe, and i is the
// index of the byte after the third one. The scanner
// needs to be eager, because there can be an extra 2
// apostrophe that can be accepted at the end of the
// string.
if i >= len(b) || b[i] != '"' {
return b[:i], escaped, b[i:], nil
}
i++
if i >= len(b) || b[i] != '"' {
return b[:i], escaped, b[i:], nil
}
i++
if i < len(b) && b[i] == '"' {
return nil, escaped, nil, newDecodeError(b[i-3:i+1], `""" not allowed in multiline basic string`)
}
return b[:i], escaped, b[i:], nil
}
case '\\':
if len(b) < i+2 {
return nil, escaped, nil, newDecodeError(b[len(b):], "need a character after \\")
}
escaped = true
i++ // skip the next character
case '\r':
if len(b) < i+2 {
return nil, escaped, nil, newDecodeError(b[len(b):], `need a \n after \r`)
}
if b[i+1] != '\n' {
return nil, escaped, nil, newDecodeError(b[i:i+2], `need a \n after \r`)
}
i++ // skip the \n
}
}
return nil, escaped, nil, newDecodeError(b[len(b):], `multiline basic string not terminated by """`)
}
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