Formatter line continuation awareness hooks.

pkg/analyzer/lib/src/services/formatter_impl.dart

Index: pkg/analyzer/lib/src/services/formatter_impl.dart
===================================================================
--- pkg/analyzer/lib/src/services/formatter_impl.dart	(revision 31147)
+++ pkg/analyzer/lib/src/services/formatter_impl.dart	(working copy)
@@ -397,7 +397,9 @@
 
   visitArgumentList(ArgumentList node) {
     token(node.leftParenthesis);
-    visitCommaSeparatedNodes(node.arguments);
+    allowContinuedLines((){
+      visitCommaSeparatedNodes(node.arguments);
+    });
     token(node.rightParenthesis);
   }
 
@@ -422,8 +424,10 @@
     visit(node.leftHandSide);
     space();
     token(node.operator);
-    space();
-    visit(node.rightHandSide);
+    allowContinuedLines((){
+      space();
+      visit(node.rightHandSide);
+    });
   }
 
   visitBinaryExpression(BinaryExpression node) {
@@ -492,11 +496,13 @@
     token(node.classKeyword);
     space();
     visit(node.name);
-    visit(node.typeParameters);
-    visitNode(node.extendsClause, precededBy: space);
-    visitNode(node.withClause, precededBy: space);
-    visitNode(node.implementsClause, precededBy: space);
-    space();
+    allowContinuedLines((){
+      visit(node.typeParameters);
+      visitNode(node.extendsClause, precededBy: space);
+      visitNode(node.withClause, precededBy: space);
+      visitNode(node.implementsClause, precededBy: space);
+      space();
+    });
     token(node.leftBracket);
     indent();
     visitNodes(node.members, precededBy: newlines, separatedBy: newlines);
@@ -554,12 +560,14 @@
     visit(node.condition);
     space();
     token(node.question);
-    space();
-    visit(node.thenExpression);
-    space();
-    token(node.colon);
-    space();
-    visit(node.elseExpression);
+    allowContinuedLines((){
+      space();
+      visit(node.thenExpression);
+      space();
+      token(node.colon);
+      space();
+      visit(node.elseExpression);
+    });
   }
 
   visitConstructorDeclaration(ConstructorDeclaration node) {
@@ -663,8 +671,10 @@
     token(node.whileKeyword);
     space();
     token(node.leftParenthesis);
-    visit(node.condition);
-    token(node.rightParenthesis);
+    allowContinuedLines((){
+      visit(node.condition);
+      token(node.rightParenthesis);
+    });
     token(node.semicolon);
   }
 
@@ -684,7 +694,9 @@
     token(node.keyword);
     space();
     visit(node.uri);
-    visitNodes(node.combinators, precededBy: space, separatedBy: space);
+    allowContinuedLines((){
+      visitNodes(node.combinators, precededBy: space, separatedBy: space);
+    });
     token(node.semicolon);
   }
 
@@ -837,11 +849,13 @@
   visitIfStatement(IfStatement node) {
     var hasElse = node.elseStatement != null;
     token(node.ifKeyword);
+    allowContinuedLines((){
+      space();
+      token(node.leftParenthesis);
+      visit(node.condition);
+      token(node.rightParenthesis);
+    });
     space();
-    token(node.leftParenthesis);
-    visit(node.condition);
-    token(node.rightParenthesis);
-    space();
     if (hasElse) {
       printAsBlock(node.thenStatement);
       space();
@@ -864,8 +878,10 @@
     space();
     visit(node.uri);
     token(node.asToken, precededBy: space, followedBy: space);
-    visit(node.prefix);
-    visitNodes(node.combinators, precededBy: space, separatedBy: space);
+    allowContinuedLines((){
+      visit(node.prefix);
+      visitNodes(node.combinators, precededBy: space, separatedBy: space);
+    });
     token(node.semicolon);
   }
 
@@ -1073,9 +1089,11 @@
       token(node.semicolon);
     } else {
       token(node.keyword);
-      space();
-      expression.accept(this);
-      token(node.semicolon);
+      allowContinuedLines((){
+        space();
+        expression.accept(this);
+        token(node.semicolon);
+      });
     }
   }
 
@@ -1209,8 +1227,16 @@
     if (node.initializer != null) {
       space();
       token(node.equals);
-      space();
-      visit(node.initializer);
+      var initializer = node.initializer;
+      if (initializer is! ListLiteral && initializer is! MapLiteral) {
+        allowContinuedLines((){
+          space();
+          visit(initializer);
+        });
+      } else {
+        space();
+        visit(initializer);
+      }
     }
   }
 
@@ -1229,8 +1255,10 @@
     token(node.keyword);
     space();
     token(node.leftParenthesis);
-    visit(node.condition);
-    token(node.rightParenthesis);
+    allowContinuedLines((){
+      visit(node.condition);
+      token(node.rightParenthesis);
+    });
     if (node.body is! EmptyStatement) {
       space();
     }
@@ -1316,6 +1344,12 @@
     }
   }
 
+  /// Allow [code] to be continued across lines.
+  allowContinuedLines(code()) {
+    indent(2);

[Brian Wilkerson, 2013/12/13 22:38:03]

Do we want to increase the indentation if allowContinuedLines is called
recursively? For example, we call it both in an assignment expression and in a
conditional expression, so the indent will be N + 4 while processing the 'then'
and 'else' conditions in the following:

  a = b ? c : d;

+    code();
+    unindent(2);
+  }
 
   /// Emit the given [modifier] if it's non null, followed by non-breaking
   /// whitespace.