Drop with + <indent> syntax

It's now `:` instead of the trailing `with`.

Author: odersky

community-build/community-projects/intent

@@ -646,15 +646,13 @@ object Parsers {
         else body()
       case _ => body()
 
-    /** If indentation is not significant, check that this is not the start of a
-     *  statement that's indented relative to the current region.
-     *  TODO: Drop if `with` is required before indented template definitions.
+    /** Check that this is not the start of a statement that's indented relative to the current region.
      */
     def checkNextNotIndented(): Unit = in.currentRegion match
       case r: IndentSignificantRegion if in.isNewLine =>
         val nextIndentWidth = in.indentWidth(in.next.offset)
         if r.indentWidth < nextIndentWidth then
-          warning(i"Line is indented too far to the right, or a `{` is missing", in.next.offset)
+          warning(i"Line is indented too far to the right, or a `{` or `:` is missing", in.next.offset)
       case _ =>
 
 /* -------- REWRITES ----------------------------------------------------------- */
@@ -1292,10 +1290,6 @@ object Parsers {
         in.nextToken()
         if in.token != INDENT then
           syntaxError(i"indented definitions expected")
-      else if in.token == WITH then
-        in.nextToken()
-        if in.token != LBRACE && in.token != INDENT then
-          syntaxError(i"indented definitions or `{` expected")
       else
         newLineOptWhenFollowedBy(LBRACE)
 

compiler/src/dotty/tools/dotc/parsing/Parsers.scala

@@ -257,7 +257,7 @@ object Tokens extends TokensCommon {
     AT, CASE)
 
   final val canEndStatTokens: TokenSet = atomicExprTokens | BitSet(
-    TYPE, GIVEN, RPAREN, RBRACE, RBRACKET, OUTDENT) // TODO: remove GIVEN once old import syntax is dropped
+    TYPE, RPAREN, RBRACE, RBRACKET, OUTDENT) // TODO: remove GIVEN once old import syntax is dropped
 
   /** Tokens that stop a lookahead scan search for a `<-`, `then`, or `do`.
    *  Used for disambiguating between old and new syntax.
@@ -272,7 +272,7 @@ object Tokens extends TokensCommon {
   final val closingRegionTokens = BitSet(RBRACE, CASE) | statCtdTokens
 
   final val canStartIndentTokens: BitSet =
-    statCtdTokens | BitSet(COLONEOL, EQUALS, ARROW, LARROW, WHILE, TRY, FOR, IF, WITH)
+    statCtdTokens | BitSet(COLONEOL, EQUALS, ARROW, LARROW, WHILE, TRY, FOR, IF)
       // `if` is excluded because it often comes after `else` which makes for awkward indentation rules  TODO: try to do without the exception
 
   /** Faced with the choice between a type and a formal parameter, the following

compiler/src/dotty/tools/dotc/parsing/Tokens.scala

@@ -121,7 +121,7 @@ class SemanticdbTests:
 
 end SemanticdbTests
 
-object SemanticdbTests with
+object SemanticdbTests:
   /** Prettyprint a text document with symbol occurrences next to each resolved identifier.
    *
    * Useful for testing purposes to ensure that SymbolOccurrence values make sense and are correct.