[clang-format] parse C# object initialisers

[jbcoe]

Summary

Treat C# object initializers as braced lists.

Allow lambdas inside C# braced lists.

[krasimir]

clang/lib/Format/UnwrappedLineParser.cpp

1978

I don't understand why this is needed, and removing this if does not cause any tests to fail.
Please add a test case that will fail if we remove this if, or consider removing otherwise.

[jbcoe]

clang/lib/Format/UnwrappedLineParser.cpp

1978

I'll remove this for now and put together a follow up patch with test cases for more obscure object initializer use cases.

[jbcoe]

Remove code without test coverage.

[krasimir]

Thank you!

clang/lib/Format/UnwrappedLineParser.cpp

 
 bool UnwrappedLineParser::parseBracedList(bool ContinueOnSemicolons,
                                           tok::TokenKind ClosingBraceKind) {
   bool HasError = false;
 
   // FIXME: Once we have an expression parser in the UnwrappedLineParser,
   // replace this by using parseAssigmentExpression() inside.
   do {
+    if (Style.isCSharp()) {
+      if (FormatTok->is(TT_JsFatArrow)) {
+        nextToken();
+        // Fat arrows can be followed by simple expressions or by child blocks
+        // in curly braces.
+        if (FormatTok->is(tok::l_brace)) {
+          parseChildBlock();
+          continue;
+        }
+      }
+    }
     if (Style.Language == FormatStyle::LK_JavaScript) {
       if (FormatTok->is(Keywords.kw_function) ||
           FormatTok->startsSequence(Keywords.kw_async, Keywords.kw_function)) {
         tryToParseJSFunction();
         continue;
       }
       if (FormatTok->is(TT_JsFatArrow)) {
         nextToken();
if (FormatTok->Tok.is(tok::l_brace)) {
     if (ShouldBreakBeforeBrace(Style, InitialToken))
       addUnwrappedLine();
 
     bool AddLevel = Style.NamespaceIndentation == FormatStyle::NI_All ||
                     (Style.NamespaceIndentation == FormatStyle::NI_Inner &&
                      DeclarationScopeStack.size() > 1);
     parseBlock(/*MustBeDeclaration=*/true, AddLevel);
     // Munch the semicolon after a namespace. This is more common than one would
-    // think. Puttin the semicolon into its own line is very ugly.
+    // think. Putting the semicolon into its own line is very ugly.
     if (FormatTok->Tok.is(tok::semi))
       nextToken();
     addUnwrappedLine();
   }
   // FIXME: Add error handling.
 }
 
 void UnwrappedLineParser::parseNew() {
   assert(FormatTok->is(tok::kw_new) && "'new' expected");
   nextToken();
+
+  if (Style.isCSharp()) {
+    do {
+      if (FormatTok->is(tok::l_brace))
+        parseBracedList();
+
+      if (FormatTok->is(tok::l_paren))
+        parseParens();
+
+      if (FormatTok->isOneOf(tok::semi, tok::comma))
+        return;
+
+      nextToken();
+    } while (!eof());
+  }
+
   if (Style.Language != FormatStyle::LK_Java)
     return;
 
   // In Java, we can parse everything up to the parens, which aren't optional.
   do {
     // There should not be a ;, { or } before the new's open paren.
     if (FormatTok->isOneOf(tok::semi, tok::l_brace, tok::r_brace))
       return;

clang/unittests/Format/FormatTestCSharp.cpp

Shape[] shapes = new[] {
   // Omitted final `,`s will change the formatting.
   verifyFormat(R"(//
 Shape[] shapes = new[] { new Circle { Radius = 2.7281, Colour = Colours.Red },
                          new Square {
                              Side = 101.1,
                              Colour = Colours.Yellow,
                          } };)",
                Style);
+
+  // Lambdas can be supplied as initialiser arguments.
+  verifyFormat(R"(//
+private Transformer _transformer = new X.Y {
+    Filler = (Shape shape) => { return new Transform.Fill(shape, RED); },
+    Scaler = (Shape shape) => { return new Transform.Resize(shape, 0.1); },
+};)",
+               Style);
 }
 
 TEST_F(FormatTestCSharp, CSharpNamedArguments) {
   FormatStyle Style = getGoogleStyle(FormatStyle::LK_CSharp);
 
   verifyFormat(R"(//
 PrintOrderDetails(orderNum: 31, productName: "Red Mug",
                   sellerName: "Gift Shop");)",