KT-337 Can't break a line before a dot

compiler/frontend/src/org/jetbrains/jet/lang/parsing/JetExpressionParsing.java

@@ -178,7 +178,10 @@ public class JetExpressionParsing extends AbstractJetParsing {
         }
     }
 
+    public static final TokenSet ALLOW_NEWLINE_OPERATIONS = TokenSet.create(DOT, SAFE_ACCESS);
+
     public static final TokenSet ALL_OPERATIONS;
+
     static {
         Set<IElementType> operations = new HashSet<IElementType>();
         Precedence[] values = Precedence.values();
@@ -272,7 +275,7 @@ public class JetExpressionParsing extends AbstractJetParsing {
 
         precedence.parseHigherPrecedence(this);
 
-        while (!myBuilder.newlineBeforeCurrentToken() && atSet(precedence.getOperations())) {
+        while (!breakedWithNewLine() && atSet(precedence.getOperations())) {
             IElementType operation = tt();
 
             parseOperationReference();
@@ -328,7 +331,7 @@ public class JetExpressionParsing extends AbstractJetParsing {
         PsiBuilder.Marker expression = mark();
         parseAtomicExpression();
         while (true) {
-            if (myBuilder.newlineBeforeCurrentToken()) {
+            if (breakedWithNewLine()) {
                 break;
             }
             else if (at(LBRACKET)) {
@@ -1704,4 +1707,8 @@ public class JetExpressionParsing extends AbstractJetParsing {
     protected JetParsing create(SemanticWhitespaceAwarePsiBuilder builder) {
         return myJetParsing.create(builder);
     }
+
+    private boolean breakedWithNewLine() {
+        return !ALLOW_NEWLINE_OPERATIONS.contains(tt()) && myBuilder.newlineBeforeCurrentToken();
+    }
 }

compiler/frontend/src/org/jetbrains/jet/lang/parsing/JetParsing.java

@@ -124,9 +124,11 @@ public class JetParsing extends AbstractJetParsing {
             parseNamespaceName();
 
             if (at(LBRACE)) {
+                // Because it's blocked namespace and it will be parsed as one of top level objects
                 firstEntry.rollbackTo();
                 return;
             }
+
             firstEntry.drop();
 
             consumeIf(SEMICOLON);
@@ -134,6 +136,7 @@ public class JetParsing extends AbstractJetParsing {
             firstEntry.rollbackTo();
         }
 
+        // TODO: Duplicate with parsing imports in parseToplevelDeclarations
         while (at(IMPORT_KEYWORD)) {
             parseImportDirective();
         }

compiler/frontend/src/org/jetbrains/jet/lang/parsing/SemanticWhitespaceAwarePsiBuilderImpl.java

@@ -25,27 +25,37 @@ public class SemanticWhitespaceAwarePsiBuilderImpl extends PsiBuilderAdapter imp
 
     @Override
     public boolean newlineBeforeCurrentToken() {
+
         if (!newlinesEnabled.peek()) return false;
+
         if (eof()) return true;
-        // TODO: maybe, memoize this somehow?
+
+        // TODO: maybe, memorize this somehow?
         for (int i = 1; i <= getCurrentOffset(); i++) {
             IElementType previousToken = rawLookup(-i);
+
             if (previousToken == JetTokens.BLOCK_COMMENT
                     || previousToken == JetTokens.DOC_COMMENT
                     || previousToken == JetTokens.EOL_COMMENT) {
                 continue;
             }
+
             if (previousToken != TokenType.WHITE_SPACE) {
                 break;
             }
+
             int previousTokenStart = rawTokenTypeStart(-i);
             int previousTokenEnd = rawTokenTypeStart(-i + 1);
+
             assert previousTokenStart >= 0;
             assert previousTokenEnd < getOriginalText().length();
+
             for (int j = previousTokenStart; j < previousTokenEnd; j++) {
-                if (getOriginalText().charAt(j) == '\n') return true;
+                if (getOriginalText().charAt(j) == '\n')
+                    return true;
             }
         }
+
         return false;
     }
 

compiler/testData/checkerWithErrorTypes/quick/regressions/kt337.jet

@@ -0,0 +1,14 @@
+//KT-337 Can't break a line before a dot
+
+class A() {
+    fun foo() {}
+}
+
+fun test() {
+    val a = A()
+
+    a
+
+      .foo() // Should be a valid expression
+
+}

compiler/testData/psi/NewLinesValidOperations.jet

@@ -0,0 +1,11 @@
+fun test() {
+    val str = ""
+
+    str
+
+        .length
+
+    str
+
+        ?.length
+}

compiler/testData/psi/NewLinesValidOperations.txt

@@ -0,0 +1,41 @@
+JetFile: NewLinesValidOperations.jet
+  NAMESPACE
+    FUN
+      PsiElement(fun)('fun')
+      PsiWhiteSpace(' ')
+      PsiElement(IDENTIFIER)('test')
+      VALUE_PARAMETER_LIST
+        PsiElement(LPAR)('(')
+        PsiElement(RPAR)(')')
+      PsiWhiteSpace(' ')
+      BLOCK
+        PsiElement(LBRACE)('{')
+        PsiWhiteSpace('\n    ')
+        PROPERTY
+          PsiElement(val)('val')
+          PsiWhiteSpace(' ')
+          PsiElement(IDENTIFIER)('str')
+          PsiWhiteSpace(' ')
+          PsiElement(EQ)('=')
+          PsiWhiteSpace(' ')
+          STRING_TEMPLATE
+            PsiElement(OPEN_QUOTE)('"')
+            PsiElement(CLOSING_QUOTE)('"')
+        PsiWhiteSpace('\n\n    ')
+        DOT_QUALIFIED_EXPRESSION
+          REFERENCE_EXPRESSION
+            PsiElement(IDENTIFIER)('str')
+          PsiWhiteSpace('\n\n        ')
+          PsiElement(DOT)('.')
+          REFERENCE_EXPRESSION
+            PsiElement(IDENTIFIER)('length')
+        PsiWhiteSpace('\n\n    ')
+        SAFE_ACCESS_EXPRESSION
+          REFERENCE_EXPRESSION
+            PsiElement(IDENTIFIER)('str')
+          PsiWhiteSpace('\n\n        ')
+          PsiElement(SAFE_ACCESS)('?.')
+          REFERENCE_EXPRESSION
+            PsiElement(IDENTIFIER)('length')
+        PsiWhiteSpace('\n')
+        PsiElement(RBRACE)('}')