Double-click selection matches some escaped characters

[anticore]

Issue Type: Bug

If you have a string with the "\t", "\n", etc. sequences followed by a word, double-clicking the word will select the escaped character as well:

VS Code version: Code 1.21.0 (9a199d7, 2018-03-07T11:01:43.521Z)
OS version: Linux x64 4.10.0-42-generic

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz (8 x 3142)
Load (avg)	0, 1, 1
Memory (System)	15.56GB (3.82GB free)
Process Argv	/usr/share/code/code --unity-launch
Screen Reader	no
VM	0%

Extensions (7)

Extension	Author (truncated)	Version
vscode-icontheme-nomo-dark	be5	1.3.5
vscode-eslint	dba	1.4.7
githistory	don	0.4.0
auto-close-tag	for	0.5.6
docthis	joe	0.6.0
python	ms-	2018.2.0
color-highlight	nau	2.3.0

(1 theme extensions excluded)

Reproduces without extensions

[Louis-DR]

I also experienced this issue. If we could specify mutliple character length patterns in editor.wordSeparators, it would solve this issue and also allow things like double underscore __ to be considered a word separator but not a single underscore _. This is useful with snake case : assert_main_loop__wrong_input for instance.

[Lexikos]

I regularly encounter this problem both with word select and word delete (ctrl-backspace).

I think that it would be ideal to have default behaviour that respects the boundaries already determined by the syntax highlighter.

In my case the escape sequence is usually `n rather than \n.

If we could specify mutliple character length patterns

If "patterns" means regex (as opposed to just strings of characters), perhaps it would cover #54571 and #147651 as well.