remove most string concat, fixes #7

remove most string concat, fixes #7

This fixes most of the egregious cases of string concat in the HTML tokenizer:
* attribute names/values
* data/comments
* script/rawtext/rcdata

It also fixes adjacent text nodes in TreeBuilder, which happens whenever space characters are adjacent to characters.

There's still an issue of preserving char codes for longer, but this should get out of the O(N^2) at least.

R=sigmund@google.com

Committed: https://github.com/dart-lang/core-elements/commit/243cbc9c40e7022f35a0a108f488ff30bb735061

[Jennifer Messerly, 2015-03-05 21:15:31]

Patchset #1 (id:1) has been deleted

[Jennifer Messerly, 2015-03-05 21:16:55]

jmesserly@google.com changed reviewers:
+ sigmund@google.com

[Jennifer Messerly, 2015-03-05 21:17:48]

Patchset #1 (id:20001) has been deleted

[Siggi Cherem (dart-lang), 2015-03-05 23:01:56]

lgtm

https://codereview.chromium.org/987433005/diff/40001/lib/src/tokenizer.dart
File lib/src/tokenizer.dart (right):

https://codereview.chromium.org/987433005/diff/40001/lib/src/tokenizer.dart#n...
lib/src/tokenizer.dart:1396:
currentStringToken.add(data).add(stream.charsUntil("-\u0000"));
maybe use cascades here and below? (instead of returning the stringtoken from
add?)

[Jennifer Messerly, 2015-03-05 23:05:24]

Committed patchset #1 (id:40001) manually as
243cbc9c40e7022f35a0a108f488ff30bb735061 (presubmit successful).