Better performance on long lists containing comments.
Fix #484.
R=tjblasi@google.com
Review URL: https://codereview.chromium.org//1595553004 .
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3e419b4..f0b9659 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# 0.2.4
+
+* Better handling for long collections with comments (#484).
+
# 0.2.3
* Support messages in assert() (#411).
diff --git a/bin/format.dart b/bin/format.dart
index 84794dd..705f3af 100644
--- a/bin/format.dart
+++ b/bin/format.dart
@@ -14,7 +14,7 @@
import 'package:dart_style/src/source_code.dart';
// Note: The following line of code is modified by tool/grind.dart.
-const version = "0.2.3";
+const version = "0.2.4";
void main(List<String> args) {
var parser = new ArgParser(allowTrailingOptions: true);
diff --git a/lib/src/chunk_builder.dart b/lib/src/chunk_builder.dart
index 54695cf..0f265ec 100644
--- a/lib/src/chunk_builder.dart
+++ b/lib/src/chunk_builder.dart
@@ -384,7 +384,11 @@
/// Ends the innermost rule.
void endRule() {
- _rules.removeLast();
+ if (_lazyRules.isNotEmpty) {
+ _lazyRules.removeLast();
+ } else {
+ _rules.removeLast();
+ }
}
/// Pre-emptively forces all of the current rules to become hard splits.
diff --git a/lib/src/source_visitor.dart b/lib/src/source_visitor.dart
index 529e420..48306ac 100644
--- a/lib/src/source_visitor.dart
+++ b/lib/src/source_visitor.dart
@@ -1880,25 +1880,42 @@
_startLiteralBody(leftBracket);
- // Always use a hard rule to split the elements. The parent chunk of
- // the collection will handle the unsplit case, so this only comes
- // into play when the collection is split.
- var rule = new Rule.hard();
- builder.startRule(rule);
-
// If a collection contains a line comment, we assume it's a big complex
// blob of data with some documented structure. In that case, the user
// probably broke the elements into lines deliberately, so preserve those.
var preserveNewlines = _containsLineComments(elements, rightBracket);
+ var rule;
+ var lineRule;
+ if (preserveNewlines) {
+ // Newlines are significant, so we'll explicitly write those. Elements
+ // on the same line all share an argument-list-like rule that allows
+ // splitting between zero, one, or all of them. This is faster in long
+ // lists than using individual splits after each element.
+ lineRule = new TypeArgumentRule();
+ builder.startLazyRule(lineRule);
+ } else {
+ // Newlines aren't significant, so use a hard rule to split the elements.
+ // The parent chunk of the collection will handle the unsplit case, so
+ // this only comes into play when the collection is split.
+ rule = new Rule.hard();
+ builder.startRule(rule);
+ }
+
for (var element in elements) {
if (element != elements.first) {
if (preserveNewlines) {
+ // See if the next element is on the next line.
if (_endLine(element.beginToken.previous) !=
_startLine(element.beginToken)) {
oneOrTwoNewlines();
+
+ // Start a new rule for the new line.
+ builder.endRule();
+ lineRule = new TypeArgumentRule();
+ builder.startLazyRule(lineRule);
} else {
- soloSplit();
+ lineRule.beforeArgument(split());
}
} else {
builder.split(nest: false, space: true);
diff --git a/pubspec.yaml b/pubspec.yaml
index ef995a4..fe4953b 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
name: dart_style
-version: 0.2.3
+version: 0.2.4
author: Dart Team <misc@dartlang.org>
description: Opinionated, automatic Dart source code formatter.
homepage: https://github.com/dart-lang/dart_style
diff --git a/test/regression/0400/0484.stmt b/test/regression/0400/0484.stmt
new file mode 100644
index 0000000..f52a190
--- /dev/null
+++ b/test/regression/0400/0484.stmt
@@ -0,0 +1,29 @@
+>>>
+var list = [
+ // comment
+ function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3), function(a: 1, b: 2, c: 3),
+];
+<<<
+var list = [
+ // comment
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+ function(a: 1, b: 2, c: 3),
+];
\ No newline at end of file
