[string] Refactor String::GetSubstitution

[string] Refactor String::GetSubstitution

Remove deep nesting and repeated code by using a switch-based structure
(instead of if-based), use clearer variable names, and separate cleanly between
immutable and mutable variables.

BUG=v8:5437
Review-Url: https://codereview.chromium.org/2776123002
Cr-Commit-Position: refs/heads/master@{#44147}
Committed: https://chromium.googlesource.com/v8/v8/+/fc44d57bcbd8c851e7be6c9513edb6e42cb8c245

[jgruber, 2017-03-27 10:39:22]

The CQ bit was checked by jgruber@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-03-27 10:39:26]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[jgruber, 2017-03-27 10:47:30]

jgruber@chromium.org changed reviewers:
+ yangguo@chromium.org

[jgruber, 2017-03-27 10:47:31]

Some refactoring prior to named-capture support.

As an aside: GetSubstitution is just slow atm (mostly due to NewSubString and
IndexOf in runtime). We should both avoid calls to it as much as possible and
fix the worst offenders (IndexOf).

https://codereview.chromium.org/2776123002/diff/1/src/objects.cc
File src/objects.cc (left):

https://codereview.chromium.org/2776123002/diff/1/src/objects.cc#oldcode11466
src/objects.cc:11466: builder.AppendCharacter('$');
The if-pattern forces deep nesting that's confusing to read.

[commit-bot: I haz the power, 2017-03-27 10:55:59]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-03-27 10:56:01]

Dry run: Try jobs failed on following builders:
  v8_win_rel_ng on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_win_rel_ng/builds/25002)
  v8_win_rel_ng_triggered on master.tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_win_rel_ng_triggered/bui...)

[jgruber, 2017-03-27 11:12:38]

The CQ bit was checked by jgruber@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-03-27 11:12:45]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-27 11:35:42]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-03-27 11:35:43]

Dry run: This issue passed the CQ dry run.

[Yang, 2017-03-27 13:01:00]

On 2017/03/27 10:47:31, jgruber wrote:
> Some refactoring prior to named-capture support.
> 
> As an aside: GetSubstitution is just slow atm (mostly due to NewSubString and
> IndexOf in runtime). We should both avoid calls to it as much as possible and
> fix the worst offenders (IndexOf).
> 
> https://codereview.chromium.org/2776123002/diff/1/src/objects.cc
> File src/objects.cc (left):
> 
> https://codereview.chromium.org/2776123002/diff/1/src/objects.cc#oldcode11466
> src/objects.cc:11466: builder.AppendCharacter('$');
> The if-pattern forces deep nesting that's confusing to read.

lgtm

[jgruber, 2017-03-27 13:04:08]

The CQ bit was checked by jgruber@chromium.org

[commit-bot: I haz the power, 2017-03-27 13:04:16]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-27 13:19:23]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1490619848411710,
"parent_rev": "960c2a1f851383748e00e454ff50398d48cd554c", "commit_rev":
"fc44d57bcbd8c851e7be6c9513edb6e42cb8c245"}

[commit-bot: I haz the power, 2017-03-27 13:19:30]

Description was changed from

==========
[string] Refactor String::GetSubstitution

Remove deep nesting and repeated code by using a switch-based structure
(instead of if-based), use clearer variable names, and separate cleanly between
immutable and mutable variables.

BUG=v8:5437
==========

to

==========
[string] Refactor String::GetSubstitution

Remove deep nesting and repeated code by using a switch-based structure
(instead of if-based), use clearer variable names, and separate cleanly between
immutable and mutable variables.

BUG=v8:5437

Review-Url: https://codereview.chromium.org/2776123002
Cr-Commit-Position: refs/heads/master@{#44147}
Committed:
https://chromium.googlesource.com/v8/v8/+/fc44d57bcbd8c851e7be6c9513edb6e42cb...
==========

[commit-bot: I haz the power, 2017-03-27 13:19:31]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/v8/v8/+/fc44d57bcbd8c851e7be6c9513edb6e42cb...