clang-format: [Java] Basic lambda support.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@222524 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Format/FormatToken.h

@@ -48,6 +48,7 @@ enum TokenType {
   TT_InheritanceColon,
   TT_InlineASMColon,
   TT_JavaAnnotation,
+  TT_LambdaArrow,
   TT_LambdaLSquare,
   TT_LeadingJavaAnnotation,
   TT_LineComment,
@@ -271,6 +272,8 @@ struct FormatToken {
 
   bool is(tok::TokenKind Kind) const { return Tok.is(Kind); }
 
+  bool is(TokenType TT) const { return Type == TT; }
+
   bool is(const IdentifierInfo *II) const {
     return II && II == Tok.getIdentifierInfo();
   }

lib/Format/TokenAnnotator.cpp

@@ -786,6 +786,9 @@ private:
         Current.Type = TT_StartOfName;
       } else if (Current.is(tok::kw_auto)) {
         AutoFound = true;
+      } else if (Current.is(tok::arrow) &&
+                 Style.Language == FormatStyle::LK_Java) {
+        Current.Type = TT_LambdaArrow;
       } else if (Current.is(tok::arrow) && AutoFound &&
                  Line.MustBeDeclaration && Current.NestingLevel == 0) {
         Current.Type = TT_TrailingReturnArrow;
@@ -1167,6 +1170,8 @@ private:
       else if (NextNonComment && NextNonComment->is(tok::colon) &&
                NextNonComment->Type == TT_DictLiteral)
         return prec::Comma;
+      else if (Current->is(TT_LambdaArrow))
+        return prec::Comma;
       else if (Current->is(tok::semi) || Current->Type == TT_InlineASMColon ||
                Current->Type == TT_SelectorName ||
                (Current->is(tok::comment) && NextNonComment &&
@@ -1701,6 +1706,8 @@ bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,
     if (Left.is(Keywords.kw_var))
       return true;
   } else if (Style.Language == FormatStyle::LK_Java) {
+    if (Left.is(TT_LambdaArrow) || Right.is(TT_LambdaArrow))
+      return true;
     if (Left.is(Keywords.kw_synchronized) && Right.is(tok::l_paren))
       return Style.SpaceBeforeParens != FormatStyle::SBPO_Never;
     if (Left.isOneOf(tok::kw_static, tok::kw_public, tok::kw_private,

unittests/Format/FormatTestJava.cpp

@@ -317,5 +317,20 @@ TEST_F(FormatTestJava, NeverAlignAfterReturn) {
                getStyleWithColumns(40));
 }
 
+TEST_F(FormatTestJava, FormatsLambdas) {
+  verifyFormat("(aaaaaaaaaa, bbbbbbbbbb) -> aaaaaaaaaa + bbbbbbbbbb;");
+  verifyFormat("(aaaaaaaaaa, bbbbbbbbbb)\n"
+               "    -> aaaaaaaaaa + bbbbbbbbbb;",
+               getStyleWithColumns(40));
+  verifyFormat("Runnable someLambda = () -> DoSomething();");
+  verifyFormat("Runnable someLambda = () -> {\n"
+               "  DoSomething();\n"
+               "}");
+
+  verifyFormat("Runnable someLambda =\n"
+               "    (int aaaaa) -> DoSomething(aaaaa);",
+               getStyleWithColumns(40));
+}
+
 } // end namespace tooling
 } // end namespace clang