Simple constructors get converted to verbose javascript

[DartBot]

This issue was originally filed by k.nei...@gmail.com

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What steps will reproduce the problem?

When running:
dart2js --out=bugreport.js example.dart
java -jar compiler.jar --js bugreport.js --js_output_file bugreport.min.js --warning_level QUIET --language_in ECMASCRIPT5

I tried using the --minify parameter, but it was not helpful.
The closure compiler could not compress it much.

This dart code:

class BadPerson{
  String _name;
  int _age;
  BadPerson(String name, int age){
    this._name = name;
    this._age = age;
  }
  String getName() => _name;
  int getAge() => _age;
  toString() => "{BadPerson " + _name + " " + _age.toString() + "}";
}

class GoodPerson{
  final String name;
  final int age;
  const GoodPerson(this.name, this.age);
  String getName() => name;
  int getAge() => age;
  toString() => "{GoodPerson " + name + " " + age.toString() + "}";
}

var badPeople = [
  new BadPerson('Kimberly', 14),
  new BadPerson('Bertha', 22),
  new BadPerson('Roberto', 30),
  new BadPerson('Gordon', 6),
  new BadPerson('Lisa', 27),
  new BadPerson('Gaye', 8),
  new BadPerson('Marian', 11),
  new BadPerson('Julie', 5),
  new BadPerson('June', 16),
  new BadPerson('John', 6)
];

var goodPeople = [
  new GoodPerson('Barbara', 14),
  new GoodPerson('Joshua', 24),
  new GoodPerson('Bertha', 20),
  new GoodPerson('Gary', 15),
  new GoodPerson('William', 16),
  new GoodPerson('Stanley', 11),
  new GoodPerson('Kelli', 30),
  new GoodPerson('Joanna', 2),
  new GoodPerson('Sylvia', 2),
  new GoodPerson('Amber', 29),
  new GoodPerson('Charlene', 19)
];

Gets compiled to this javascript:

Isolate.$lazy($, "badPeople", "badPeople", "get$badPeople", function() {
  var t1, t2, t3, t4, t5, t6, t7, t8, t9, t10;
  t1 = new D.BadPerson(null, null);
  t1._name = "Kimberly";
  t1._age = 14;
  t2 = new D.BadPerson(null, null);
  t2._name = "Bertha";
  t2._age = 22;
  t3 = new D.BadPerson(null, null);
  t3._name = "Roberto";
  t3._age = 30;
  t4 = new D.BadPerson(null, null);
  t4._name = "Gordon";
  t4._age = 6;
  t5 = new D.BadPerson(null, null);
  t5._name = "Lisa";
  t5._age = 27;
  t6 = new D.BadPerson(null, null);
  t6._name = "Gaye";
  t6._age = 8;
  t7 = new D.BadPerson(null, null);
  t7._name = "Marian";
  t7._age = 11;
  t8 = new D.BadPerson(null, null);
  t8._name = "Julie";
  t8._age = 5;
  t9 = new D.BadPerson(null, null);
  t9._name = "June";
  t9._age = 16;
  t10 = new D.BadPerson(null, null);
  t10._name = "John";
  t10._age = 6;
  return [t1, t2, t3, t4, t5, t6, t7, t8, t9, t10];
});
Isolate.$lazy($, "goodPeople", "goodPeople", "get$goodPeople", function() {
  return [new D.GoodPerson("Barbara", 14), new D.GoodPerson("Joshua", 24), new D.GoodPerson("Bertha", 20), new D.GoodPerson("Gary", 15), new D.GoodPerson("William", 16), new D.GoodPerson("Stanley", 11), new D.GoodPerson("Kelli", 30), new D.GoodPerson("Joanna", 2), new D.GoodPerson("Sylvia", 2), new D.GoodPerson("Amber", 29), new D.GoodPerson("Charlene", 19)];
});

What is the expected output? What do you see instead?

The BadPerson class is just as simple as the GoodPerson class.
I would expect them to convert to somewhat similar javascript.
This can make a huge filesize difference when large arrays of Person objects are constructed.
Simply using final and const changed my .js filesize from 3 MB to 1 MB.

What version of the product are you using? On what operating system?
Dart 1.0.0.3_r30188 on Windows 7, 64bit

Please provide any additional information below.

In attachment you'll find a simple example which clearly shows compilation to javascript generates much larger files while there doesn't seem to be any need for it.

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Attachment:
bugreport.7z (2.60 MB)

[sethladd]

Added Area-Dart2JS, Triaged labels.

[DartBot]

This comment was originally written by ngeoffray@google.com

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Set owner to ngeoffray@google.com.
Added Accepted label.

[peter-ahe-google]

I believe this is a duplicate of 9757 (which describes the problem of inlining constructors (and other things) when this doesn't pay off).

But I think k.neirynck can get much better code without waiting for 9757 to be fixed. Simply change:

  BadPerson(String name, int age){
    this._name = name;
    this._age = age;
  }

to:

  BadPerson(String name, int age)
      : this._name = name,
        this._age = age;

or even shorter:

  BadPerson(this._name, this._age);

This generates:

Isolate.$lazy($, "badPeople", "badPeople", "get$badPeople", function() {
  return [new V.BadPerson("Kimberly", 14), new V.BadPerson("Bertha", 22), new V.BadPerson("Roberto", 30), new V.BadPerson("Gordon", 6), new V.BadPerson("Lisa", 27), new V.BadPerson("Gaye", 8), new V.BadPerson("Marian", 11), new V.BadPerson("Julie", 5), new V.BadPerson("June", 16), new V.BadPerson("John", 6)];
});
Isolate.$lazy($, "goodPeople", "goodPeople", "get$goodPeople", function() {
  return [new V.GoodPerson("Barbara", 14), new V.GoodPerson("Joshua", 24), new V.GoodPerson("Bertha", 20), new V.GoodPerson("Gary", 15), new V.GoodPerson("William", 16), new V.GoodPerson("Stanley", 11), new V.GoodPerson("Kelli", 30), new V.GoodPerson("Joanna", 2), new V.GoodPerson("Sylvia", 2), new V.GoodPerson("Amber", 29), new V.GoodPerson("Charlene", 19)];
});

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Added Duplicate label.
Marked as being merged into #9757.