commonMain.moe.tlaster.twitter.parser.tokenizer.State.kt Maven / Gradle / Ivy
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package moe.tlaster.twitter.parser.tokenizer
private val asciiUppercase = 'A'..'Z'
private val asciiLowercase = 'a'..'z'
private val asciiAlpha = asciiUppercase + asciiLowercase
private val asciiDigit = '0'..'9'
private val asciiAlphanumeric = asciiAlpha + asciiDigit
private val asciiAlphanumericUnderscore = asciiAlphanumeric + '_'
private val asciiAlphanumericUnderscoreDash = asciiAlphanumericUnderscore + '-'
private val asciiAlphanumericUnderscoreDashPlus = asciiAlphanumericUnderscoreDash + '+'
private val asciiUpperHexDigit = 'A'..'F'
private val asciiLowerHexDigit = 'a'..'f'
private val asciiHexDigit = asciiUpperHexDigit + asciiLowerHexDigit
private const val NULL = '\u0000'
private const val TAB = '\u0009'
private const val LF = '\u000A'
private val emptyChar = listOf(TAB, LF, '\u000C', '\u0020', ' ')
private val asciiAlphanumericAndEmpty = asciiAlphanumeric + ' ' + TAB + LF
private val urlChar = asciiAlphanumeric + "-._~:/?#[]@!\$&'()*+,;=".toList()
private fun prevIsSpace(reader: Reader): Boolean {
return prevIsIn(reader, emptyChar)
}
private fun prevIsIn(reader: Reader, chars: List): Boolean {
// position == 1 means it is at the beginning of the string, since we consume the first character
return reader.position == 1 || reader.readAt(reader.position - 2) in chars
}
internal sealed interface State {
fun read(tokenizer: Tokenizer, reader: Reader)
}
internal data object DataState : State {
override fun read(tokenizer: Tokenizer, reader: Reader) {
when (val current = reader.consume()) {
'h' -> tokenizer.switch(HState)
'$', '＄' -> tokenizer.switch(DollarState)
'@', '＠' -> tokenizer.switch(AtState)
'.' -> tokenizer.switch(DotState)
'#', '＃' -> tokenizer.switch(HashState)
':' -> tokenizer.switch(ColonState)
eof -> tokenizer.emit(TokenCharacterType.Eof, reader.position)
else -> tokenizer.emit(TokenCharacterType.Character, reader.position)
}
}
}
internal data object ColonState : State {
override fun read(tokenizer: Tokenizer, reader: Reader) {
val current = reader.consume()
if (current in asciiAlphanumericUnderscore && tokenizer.enableEmoji) {
tokenizer.emit(TokenCharacterType.Emoji, reader.position - 1)
tokenizer.switch(EmojiState)
reader.pushback()
} else {
tokenizer.emit(TokenCharacterType.Character, reader.position - 1)
tokenizer.switch(DataState)
reader.pushback()
}
}
}
internal data object EmojiState : State {
override fun read(tokenizer: Tokenizer, reader: Reader) {
when (val current = reader.consume()) {
in asciiAlphanumericUnderscore -> {
tokenizer.emit(TokenCharacterType.Emoji, reader.position)
}
':' -> {
tokenizer.emit(TokenCharacterType.Emoji, reader.position)
tokenizer.accept()
tokenizer.switch(DataState)
}
else -> {
// reject
var start = reader.position - 1
while (start > 0) {
if (tokenizer.readAt(start - 1) != TokenCharacterType.Emoji) {
break
}
start--
}
tokenizer.emitRange(TokenCharacterType.Character, start, reader.position)
tokenizer.accept()
tokenizer.switch(DataState)
reader.pushback()
}
}
}
}
internal data object HState : State {
override fun read(tokenizer: Tokenizer, reader: Reader) {
if (reader.isFollowedBy("ttps://", ignoreCase = true)) {
tokenizer.emitRange(TokenCharacterType.Url, reader.position - 1, reader.position - 1 + "https://".length)
tokenizer.switch(UrlState)
reader.consume("ttps://".length)
} else if (reader.isFollowedBy("ttp://", ignoreCase = true)) {
tokenizer.emitRange(TokenCharacterType.Url, reader.position - 1, reader.position - 1 + "http://".length)
tokenizer.switch(UrlState)
reader.consume("ttp://".length)
} else {
tokenizer.emit(TokenCharacterType.Character, reader.position)
tokenizer.switch(DataState)
}
}
}
internal data object UrlState : State {
private val urlEscapeChars = listOf(
'!',
'~',
'*',
'\'',
'(',
')',
';',
':',
'+',
',',
'%',
'[',
']',
)
private fun urlCheck(tokenizer: Tokenizer, reader: Reader) {
var index = reader.position - 2
while (index > 0) {
if (tokenizer.readAt(index) != TokenCharacterType.Url) {
break
}
index--
}
val url = reader.readAt(index, reader.position - index)
if (!url.contains(".")) {
tokenizer.emitRange(TokenCharacterType.Character, index, reader.position)
tokenizer.switch(DataState)
reader.pushback()
} else {
tokenizer.accept()
tokenizer.switch(DataState)
reader.pushback()
}
}
override fun read(tokenizer: Tokenizer, reader: Reader) {
when (val current = reader.consume()) {
in emptyChar + eof -> {
urlCheck(tokenizer, reader)
}
':' -> {
if (tokenizer.enableEscapeInUrl) {
tokenizer.emit(TokenCharacterType.Url, reader.position)
} else {
val next = reader.next()
if (next in asciiDigit) {
tokenizer.emit(TokenCharacterType.Url, reader.position)
tokenizer.switch(UrlPortState)
} else {
// tokenizer.accept()
// tokenizer.switch(DataState)
// reader.pushback()
urlCheck(tokenizer, reader)
}
}
}
else -> {
if (current in urlEscapeChars) {
if (tokenizer.enableEscapeInUrl) {
val next = reader.next()
if (next in emptyChar + eof) {
// tokenizer.accept()
// tokenizer.switch(DataState)
// reader.pushback()
urlCheck(tokenizer, reader)
} else {
tokenizer.emit(TokenCharacterType.Url, reader.position)
}
} else {
// tokenizer.accept()
// tokenizer.switch(DataState)
// reader.pushback()
urlCheck(tokenizer, reader)
}
} else {
if (!current.isLetterOrDigit() && current != '/') {
val next = reader.next()
if (next in emptyChar + eof) {
// tokenizer.accept()
// tokenizer.switch(DataState)
// reader.pushback()
urlCheck(tokenizer, reader)
} else {
tokenizer.emit(TokenCharacterType.Url, reader.position)
}
} else {
if (tokenizer.enableNonAsciiInUrl) {
tokenizer.emit(TokenCharacterType.Url, reader.position)
} else {
if (current in urlChar) {
tokenizer.emit(TokenCharacterType.Url, reader.position)
} else {
// tokenizer.accept()
// tokenizer.switch(DataState)
// reader.pushback()
urlCheck(tokenizer, reader)
}
}
}
}
}
}
}
}
internal data object UrlPortState : State {
override fun read(tokenizer: Tokenizer, reader: Reader) {
when (val current = reader.consume()) {
in asciiDigit -> {
tokenizer.emit(TokenCharacterType.Url, reader.position)
}
in listOf('/', '?') -> {
tokenizer.emit(TokenCharacterType.Url, reader.position)
tokenizer.switch(UrlState)
}
in emptyChar + eof -> {
tokenizer.accept()
tokenizer.switch(DataState)
reader.pushback()
}
else -> {
tokenizer.accept()
tokenizer.switch(DataState)
reader.pushback()
}
}
}
}
internal data object DollarState : State {
override fun read(tokenizer: Tokenizer, reader: Reader) {
if (prevIsSpace(reader)) {
when (val current = reader.consume()) {
in asciiAlphanumeric -> {
tokenizer.emit(TokenCharacterType.Cash, reader.position - 1)
tokenizer.switch(CashTagState)
reader.pushback()
}
else -> {
tokenizer.emit(TokenCharacterType.Character, reader.position - 1)
tokenizer.switch(DataState)
reader.pushback()
}
}
} else {
tokenizer.emit(TokenCharacterType.Character, reader.position)
tokenizer.switch(DataState)
}
}
}
internal data object CashTagState : State {
private fun cashCheck(tokenizer: Tokenizer, reader: Reader) {
var index = reader.position - 2
while (index > 0) {
if (tokenizer.readAt(index) != TokenCharacterType.Cash) {
break
}
index--
}
val cash = reader.readAt(index + 1, reader.position - index - 2).trimStart('$').trimStart('＄')
if (cash.all { it in asciiDigit }) {
tokenizer.emitRange(TokenCharacterType.Character, index, reader.position)
tokenizer.switch(DataState)
reader.pushback()
} else {
tokenizer.accept()
tokenizer.switch(DataState)
reader.pushback()
}
}
override fun read(tokenizer: Tokenizer, reader: Reader) {
when (val current = reader.consume()) {
in asciiAlphanumeric -> {
tokenizer.emit(TokenCharacterType.Cash, reader.position)
}
else -> {
cashCheck(tokenizer, reader)
// tokenizer.accept()
// tokenizer.switch(DataState)
// reader.pushback()
}
}
}
}
internal data object AtState : State {
override fun read(tokenizer: Tokenizer, reader: Reader) {
if (prevIsSpace(reader) || !prevIsIn(reader, asciiAlphanumericUnderscore + listOf('@'))) {
val userNameTokens = asciiAlphanumericUnderscore + tokenizer.validMarkInUserName
when (val current = reader.consume()) {
in userNameTokens -> {
tokenizer.emit(TokenCharacterType.UserName, reader.position - 1)
tokenizer.switch(UserNameState)
reader.pushback()
}
else -> {
tokenizer.emit(TokenCharacterType.Character, reader.position - 1)
tokenizer.switch(DataState)
reader.pushback()
}
}
} else {
tokenizer.emit(TokenCharacterType.Character, reader.position)
tokenizer.switch(DataState)
}
}
}
internal data object UserNameState : State {
override fun read(tokenizer: Tokenizer, reader: Reader) {
val userNameTokens = asciiAlphanumericUnderscore
when (val current = reader.consume()) {
in userNameTokens -> {
tokenizer.emit(TokenCharacterType.UserName, reader.position)
}
in tokenizer.validMarkInUserName -> {
val next = reader.next()
if (next.isLetterOrDigit()) {
tokenizer.emit(TokenCharacterType.UserName, reader.position)
} else {
tokenizer.accept()
tokenizer.switch(DataState)
reader.pushback()
}
}
else -> {
tokenizer.accept()
tokenizer.switch(DataState)
reader.pushback()
}
}
}
}
private fun findBackwardValidUrl(reader: Reader): Int {
var position = reader.position
while (position > 0) {
if (reader.readAt(position - 1) !in urlChar) {
// not -1 because we want the position right after the text
return position
}
position--
}
// is at the beginning of the string
return 0
}
internal data object DotState : State {
override fun read(tokenizer: Tokenizer, reader: Reader) {
if (reader.readAt(reader.position) in asciiAlphanumeric && tokenizer.enableDomainDetection &&
reader.position > 1 &&
tokenizer.readAt(reader.position - 2) == TokenCharacterType.Character) {
val start = findBackwardValidUrl(reader)
if (!reader.readAt(start).isLetterOrDigit()) {
tokenizer.emit(TokenCharacterType.Character, reader.position)
tokenizer.switch(DataState)
} else {
tokenizer.emitRange(TokenCharacterType.Url, start, reader.position)
tokenizer.switch(HeadlessUrlState)
}
} else {
tokenizer.emit(TokenCharacterType.Character, reader.position)
tokenizer.switch(DataState)
}
}
}
internal data object HeadlessUrlState : State {
override fun read(tokenizer: Tokenizer, reader: Reader) {
when (val current = reader.consume()) {
!in asciiAlphanumeric -> {
reader.pushback()
val start = findBackwardValidUrl(reader)
val value = reader.readAt(start, reader.position - start).split('.').lastOrNull()?.takeWhile {
it in asciiAlpha
}
if (value != null && DomainList.any { it.equals(value, ignoreCase = true) }) {
tokenizer.emitRange(TokenCharacterType.Url, start, reader.position)
} else {
tokenizer.emitRange(TokenCharacterType.Character, start, reader.position)
}
tokenizer.accept()
tokenizer.switch(DataState)
}
else -> {
tokenizer.emit(TokenCharacterType.Url, reader.position)
}
}
}
}
internal data object HashState : State {
override fun read(tokenizer: Tokenizer, reader: Reader) {
if (prevIsSpace(reader)) {
val current = reader.consume()
if (current.isLetterOrDigit() || current == '_') {
tokenizer.emit(TokenCharacterType.HashTag, reader.position - 1)
tokenizer.switch(HashTagState)
reader.pushback()
} else {
tokenizer.emit(TokenCharacterType.Character, reader.position - 1)
tokenizer.switch(DataState)
reader.pushback()
}
} else {
tokenizer.emit(TokenCharacterType.Character, reader.position)
tokenizer.switch(DataState)
}
}
}
internal data object HashTagState : State {
override fun read(tokenizer: Tokenizer, reader: Reader) {
val current = reader.consume()
if (current.isLetterOrDigit() || current == '_') {
tokenizer.emit(TokenCharacterType.HashTag, reader.position)
} else {
tokenizer.accept()
tokenizer.switch(DataState)
reader.pushback()
}
}
}