align fasta.PrecedenceInfo.precedence with analyzer.TokenType.precedence

align fasta.PrecedenceInfo.precedence with analyzer.TokenType.precedence

This updates fasta precedence to match analyzer:

* '!'   0  --> 15
* '~'   0  --> 15

* '--'  15 --> 16
* '++'  15 --> 16
* '.'   15 --> 16
* '?.'  15 --> 16
* '('   15 --> 16
* '['   15 --> 16

And updates analyzer precedence to match fasta:

* '--'  15 --> 16
* '++'  15 --> 16

* '[]'  16 --> 0
* '[]=' 16 --> 0

R=ahe@google.com, brianwilkerson@google.com

Committed: https://github.com/dart-lang/sdk/commit/d7c4cad542a8314491d13b685312f7926ecfeeee

[danrubel, 2017-03-15 11:18:37]

Description was changed from

==========
align fasta.PrecedenceInfo.precedence with analyzer.TokenType.precedence

This updates the fasta precedence to match analyzer:

* '!'   0  --> 15
* '[]'  0  --> 15
* '~'   0  --> 15

* '--'  unchanged 15
* '++'  unchanged 15

* '[]=' 0  --> 16

* '.'   15 --> 16
* '?.'  15 --> 16
* '('   15 --> 16
* '['   15 --> 16
==========

to

==========
align fasta.PrecedenceInfo.precedence with analyzer.TokenType.precedence

This updates fasta precedence to match analyzer:

* '!'   0  --> 15
* '[]'  0  --> 15
* '~'   0  --> 15

* '[]=' 0  --> 16
* '--'  15 --> 16
* '++'  15 --> 16
* '.'   15 --> 16
* '?.'  15 --> 16
* '('   15 --> 16
* '['   15 --> 16

And updates analyzer precedence to match fasta:

* '--'  15 --> 16
* '++'  15 --> 16
==========

[danrubel, 2017-03-15 11:21:21]

danrubel@google.com changed reviewers:
+ ahe@google.com, brianwilkerson@google.com, paulberry@google.com

[ahe, 2017-03-15 12:25:36]

I'm always in trouble when it comes to precedence order.

How do we test that this doesn't break dart2js? Have you found any language
tests that would be sensitive to dart2js being broken with respect to precedence
order?

[danrubel, 2017-03-15 13:32:42]

On 2017/03/15 12:25:36, ahe wrote:
> I'm always in trouble when it comes to precedence order.
> 
> How do we test that this doesn't break dart2js? Have you found any language
> tests that would be sensitive to dart2js being broken with respect to
precedence
> order?

Yes. My first attempt (patch set 1) breaks a plethora of dart2js tests.

To make this work, I changed all the fasta precedence level 15 to 16, then
changed analyzer ++/-- precedence from TokenClass.UNARY_PREFIX_OPERATOR (15) to
TokenClass.UNARY_POSTFIX_OPERATOR (16) so that they matched fasta.

Tests pass, but suggestions for additional precedence related tests that should
be added to both analyzer and fasta are most welcome.

[Brian Wilkerson, 2017-03-15 13:50:33]

https://codereview.chromium.org/2755433004/diff/20001/pkg/front_end/lib/src/s...
File pkg/front_end/lib/src/scanner/token.dart (right):

https://codereview.chromium.org/2755433004/diff/20001/pkg/front_end/lib/src/s...
pkg/front_end/lib/src/scanner/token.dart:1012: const TokenType._('MINUS_MINUS',
TokenClass.UNARY_POSTFIX_OPERATOR, '--');
I'm not sure what the right answer is here. Note that both '--' and '++' are
both prefix and postfix operators. I don't know whether using the smaller or
larger of the two is the right solution, nor am I convinced that it makes a
difference.

I'm confident that it doesn't matter for analyzer's parser, because it doesn't
use any precedence information for anything. I'd have to do a code search to see
where analyzer / server does use this information.

[danrubel, 2017-03-17 18:19:12]

Description was changed from

==========
align fasta.PrecedenceInfo.precedence with analyzer.TokenType.precedence

This updates fasta precedence to match analyzer:

* '!'   0  --> 15
* '[]'  0  --> 15
* '~'   0  --> 15

* '[]=' 0  --> 16
* '--'  15 --> 16
* '++'  15 --> 16
* '.'   15 --> 16
* '?.'  15 --> 16
* '('   15 --> 16
* '['   15 --> 16

And updates analyzer precedence to match fasta:

* '--'  15 --> 16
* '++'  15 --> 16
==========

to

==========
align fasta.PrecedenceInfo.precedence with analyzer.TokenType.precedence

This updates fasta precedence to match analyzer:

* '!'   0  --> 15
* '~'   0  --> 15

* '--'  15 --> 16
* '++'  15 --> 16
* '.'   15 --> 16
* '?.'  15 --> 16
* '('   15 --> 16
* '['   15 --> 16

And updates analyzer precedence to match fasta:

* '--'  15 --> 16
* '++'  15 --> 16

* '[]'  16 --> 0
* '[]=' 16 --> 0
==========

[danrubel, 2017-03-18 14:38:36]

Added test and updated precedence per discussions.

PTAL.

[Brian Wilkerson, 2017-03-18 16:11:28]

lgtm

https://codereview.chromium.org/2755433004/diff/80001/tests/language/preceden...
File tests/language/precedence_test.dart (right):

https://codereview.chromium.org/2755433004/diff/80001/tests/language/preceden...
tests/language/precedence_test.dart:6: library precedence_test;
Unless the library directive is useful to the test runner, consider dropping it.

[ahe, 2017-03-20 12:19:46]

lgtm

https://codereview.chromium.org/2755433004/diff/80001/tests/language/preceden...
File tests/language/precedence_test.dart (right):

https://codereview.chromium.org/2755433004/diff/80001/tests/language/preceden...
tests/language/precedence_test.dart:20: void testBang() {
I don't feel this is as well tested as the others.

The problem is that `(!true) == false` is the same as `!(true == false)`.

On the other hand, this will cause an error if precedence is wrong:

Expect.isFalse(!x == x);

Or like this:

Expect.equals(!x == x, !(x == x));

[danrubel, 2017-03-20 13:06:49]

https://codereview.chromium.org/2755433004/diff/80001/tests/language/preceden...
File tests/language/precedence_test.dart (right):

https://codereview.chromium.org/2755433004/diff/80001/tests/language/preceden...
tests/language/precedence_test.dart:6: library precedence_test;
On 2017/03/18 16:11:28, Brian Wilkerson wrote:
> Unless the library directive is useful to the test runner, consider dropping
it.

I don't believe its needed. Removed.

https://codereview.chromium.org/2755433004/diff/80001/tests/language/preceden...
tests/language/precedence_test.dart:20: void testBang() {
On 2017/03/20 12:19:45, ahe wrote:
> I don't feel this is as well tested as the others.
> 
> The problem is that `(!true) == false` is the same as `!(true == false)`.
> 
> On the other hand, this will cause an error if precedence is wrong:
> 
> Expect.isFalse(!x == x);
> 
> Or like this:
> 
> Expect.equals(!x == x, !(x == x));

Good point.  Test updated.

[danrubel, 2017-03-20 16:47:39]

Description was changed from

==========
align fasta.PrecedenceInfo.precedence with analyzer.TokenType.precedence

This updates fasta precedence to match analyzer:

* '!'   0  --> 15
* '~'   0  --> 15

* '--'  15 --> 16
* '++'  15 --> 16
* '.'   15 --> 16
* '?.'  15 --> 16
* '('   15 --> 16
* '['   15 --> 16

And updates analyzer precedence to match fasta:

* '--'  15 --> 16
* '++'  15 --> 16

* '[]'  16 --> 0
* '[]=' 16 --> 0
==========

to

==========
align fasta.PrecedenceInfo.precedence with analyzer.TokenType.precedence

This updates fasta precedence to match analyzer:

* '!'   0  --> 15
* '~'   0  --> 15

* '--'  15 --> 16
* '++'  15 --> 16
* '.'   15 --> 16
* '?.'  15 --> 16
* '('   15 --> 16
* '['   15 --> 16

And updates analyzer precedence to match fasta:

* '--'  15 --> 16
* '++'  15 --> 16

* '[]'  16 --> 0
* '[]=' 16 --> 0

R=ahe@google.com, brianwilkerson@google.com

Committed:
https://github.com/dart-lang/sdk/commit/d7c4cad542a8314491d13b685312f7926ecfeeee
==========

[danrubel, 2017-03-20 16:47:40]

Committed patchset #6 (id:100001) manually as
d7c4cad542a8314491d13b685312f7926ecfeeee (presubmit successful).