Jun 27, 2022 · Jun 25, 2022 · Jun 25, 2022
diff --git a/compiler/src/dotty/tools/dotc/parsing/Parsers.scala b/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
     */
    def selfType(): ValDef =
      if (in.isIdent || in.token == THIS)
 && in.lookahead.isColon && followingIsSelfType()
            || in.lookahead.token == ARROW
        &&(in.lookahead.isColon && followingIsSelfType()
            || in.lookahead.token == ARROW)
      then
        atSpan(in.offset) {
          val selfName =
diff --git a/compiler/src/dotty/tools/dotc/parsing/Scanners.scala b/compiler/src/dotty/tools/dotc/parsing/Scanners.scala
          true
        else token == COLONfollow && (inTemplate || fewerBracesEnabled)
      if enabled then
 lookAhead()
 peekAhead()
        val atEOL = isAfterLineEnd || token == EOF
        reset()
        if atEOL then token = COLONeol
        insert(OUTDENT, offset)
      case _ =>

    deflookAhead() =
    defpeekAhead() =
      prev.copyFrom(this)
      getNextToken(token)
      if token == END && !isEndMarker then token = IDENTIFIER

    def reset() = {
    def reset() =
      next.copyFrom(this)
      this.copyFrom(prev)
    }

    def closeIndented() = currentRegion match
      case r: Indented if !r.isOutermost => insert(OUTDENT, offset)
      }
      (token: @switch) match {
        case CASE =>
 lookAhead()
 peekAhead()
          if (token == CLASS) fuse(CASECLASS)
          else if (token == OBJECT) fuse(CASEOBJECT)
          else reset()
        case SEMI =>
 lookAhead()
 peekAhead()
          if (token != ELSE) reset()
        case COMMA =>
          def isEnclosedInParens(r: Region): Boolean = r match
            case r: Indented if isEnclosedInParens(r.outer) =>
              insert(OUTDENT, offset)
            case _ =>
 lookAhead()
 peekAhead()
              if isAfterLineEnd
                 && currentRegion.commasExpected
                 && (token == RPAREN || token == RBRACKET || token == RBRACE || token == OUTDENT)
     *  The token is computed via fetchToken, so complex two word
     *  tokens such as CASECLASS are not recognized.
     *  Newlines and indent/unindent tokens are skipped.
     *
     *  Restriction: `lookahead` is illegal if the current token is INTERPOLATIONID
     */
 def lookahead: TokenData =
    def lookahead: TokenData =
      if next.token == EMPTY then
        lookAhead()
        assert(token != INTERPOLATIONID)
          // INTERPOLATONIDs are followed by a string literal, which can set next
          // in peekAhead(). In that case, the following reset() would forget that token.
        peekAhead()
        reset()
      next

diff --git a/tests/pos/i15514.scala b/tests/pos/i15514.scala

 object Main { s"Hello $Main.toStr!" }

 object Alt { s"Hello ${Alt}.toStr!" }
Original file line number	Diff line number	Diff line change
Expand Up		@@ -3957,8 +3957,8 @@ object Parsers {
		*/
		def selfType(): ValDef =
		if (in.isIdent \|\| in.token == THIS)
		&& in.lookahead.isColon && followingIsSelfType()
		\|\| in.lookahead.token == ARROW
		&&(in.lookahead.isColon && followingIsSelfType()
		\|\| in.lookahead.token == ARROW)
		then
		atSpan(in.offset) {
		val selfName =
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -662,7 +662,7 @@ object Scanners {
		true
		else token == COLONfollow && (inTemplate \|\| fewerBracesEnabled)
		if enabled then
		lookAhead()
		peekAhead()
		val atEOL = isAfterLineEnd \|\| token == EOF
		reset()
		if atEOL then token = COLONeol
Expand DownExpand Up		@@ -690,15 +690,14 @@ object Scanners {
		insert(OUTDENT, offset)
		case _ =>

		deflookAhead() =
		defpeekAhead() =
		prev.copyFrom(this)
		getNextToken(token)
		if token == END && !isEndMarker then token = IDENTIFIER

		def reset() = {
		def reset() =
		next.copyFrom(this)
		this.copyFrom(prev)
		}

		def closeIndented() = currentRegion match
		case r: Indented if !r.isOutermost => insert(OUTDENT, offset)
Expand All		@@ -717,12 +716,12 @@ object Scanners {
		}
		(token: @switch) match {
		case CASE =>
		lookAhead()
		peekAhead()
		if (token == CLASS) fuse(CASECLASS)
		else if (token == OBJECT) fuse(CASEOBJECT)
		else reset()
		case SEMI =>
		lookAhead()
		peekAhead()
		if (token != ELSE) reset()
		case COMMA =>
		def isEnclosedInParens(r: Region): Boolean = r match
Expand All		@@ -733,7 +732,7 @@ object Scanners {
		case r: Indented if isEnclosedInParens(r.outer) =>
		insert(OUTDENT, offset)
		case _ =>
		lookAhead()
		peekAhead()
		if isAfterLineEnd
		&& currentRegion.commasExpected
		&& (token == RPAREN \|\| token == RBRACKET \|\| token == RBRACE \|\| token == OUTDENT)
Expand DownExpand Up		@@ -1083,11 +1082,14 @@ object Scanners {
		* The token is computed via fetchToken, so complex two word
		* tokens such as CASECLASS are not recognized.
		* Newlines and indent/unindent tokens are skipped.
		*
		* Restriction: `lookahead` is illegal if the current token is INTERPOLATIONID
		*/
		def lookahead: TokenData =
		def lookahead: TokenData =
		if next.token == EMPTY then
		lookAhead()
		assert(token != INTERPOLATIONID)
		// INTERPOLATONIDs are followed by a string literal, which can set next
		// in peekAhead(). In that case, the following reset() would forget that token.
		peekAhead()
		reset()
		next

Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,4 @@

		object Main { s"Hello $Main.toStr!" }

		object Alt { s"Hello ${Alt}.toStr!" }