-- Warning: tests/warn/i16072.scala:4:2 --------------------------------------------------------------------------------4 | def x = 1 // warn too far right
 | ^
 | Line is indented too far to the right, or a `{` or `:` is missing
-- [E222] Syntax Warning: tests/warn/i16072.scala:3:7 ------------------------------------------------------------------3 |object Hello_: // warn colon in name without backticks because the body is empty
 | ^^^^^^^
 | name `Hello_:` should be enclosed in backticks

 def checkNextNotIndented(): Unit =
- if in.isNewLine then
+ if testNextNotIndented() then
+ warning(em"Line is indented too far to the right, or a `{` or `:` is missing", in.next.offset)
+
+ def testNextNotIndented(): Boolean =
+ in.isNewLine && {
 val nextIndentWidth = in.indentWidth(in.next.offset)
- if in.currentRegion.indentWidth < nextIndentWidth then
- warning(em"Line is indented too far to the right, or a `{` or `:` is missing", in.next.offset)
+ in.currentRegion.indentWidth < nextIndentWidth
+ }
+ // Catch inadvertent fusion of punctuation as operator char (name_:)
+ private def checkSuspiciousColon(name: Name, offset: Offset): Unit =
+ if name.endsWith(":") && testNextNotIndented() then
+ warning(em"name ends in `:` before indented line", offset-1)
+
 def classDef(start: Offset, mods: Modifiers): TypeDef = atSpan(start, nameStart) {
- classDefRest(start, mods, ident().toTypeName)
+ val name = ident()
+ checkSuspiciousColon(name, nameStart)
+ classDefRest(start, mods, name.toTypeName)
 }

Welcome to Scala 3.8.0-RC1-bin-SNAPSHOT-nonbootstrapped-git-d394833 (23.0.2, Java OpenJDK 64-Bit Server VM).
Type in expressions for evaluation. Or try :help.
scala> locally {
 | val x = 42
 | val y = 27
 | }
1 warning found
-- [E223] Syntax Warning: ------------------------------------------------------
3 | val y = 27
 | ^
 | Line is indented too far to the left, or a '}' is missing
 |
 | longer explanation available when compiling with `-explain`
scala>
➜ snips scala-cli repl --server=false -S 3.7.2
Welcome to Scala 3.7.2 (23.0.2, Java OpenJDK 64-Bit Server VM).
Type in expressions for evaluation. Or try :help.
scala> locally {
 | val x = 42
 | val y = 27
 | }
1 warning found
-- Warning: --------------------------------------------------------------------
3 | val y = 27
 | ^
 | Line is indented too far to the left, or a `}` is missing