Regex find does not match on beginning and end of lines (missing multiline flag?)

[erikbra]

• VSCode Version: 1.4.0
• OS Version: Windows

Steps to Reproduce:

1. Search for regex including beginning or end of line matches. Examples:
   • ^\s*$\n (should match empty lines)
   • ^A.*B$ (should match every line starting with A and ending with B (e.g. A****************B)
2. Expected: match
3. Actual: No match.

Ref. issue #313, which is closed, but in essense the same, or at least very similar.

Esp. @alexandrudima 's comment, stating that this might be to a missing multiline flag passed to the Javascript regex engine.

#313 (comment)

[erikbra]

This does not work as expected in September (insiders build).

^\s*$\n matches on end-of-every-line. Should only match empty lines. It says:

^ - start of line
\s* - none or more whitespaces
$ - end of line
\n - newline

^\s*$\n matches empty lines in all other regex editors (sublime, Visual studio, regex testers)
^\s+$\n matches empty lines.

It looks as if ^\s*$\n starts matching on the previous line (I can tell from looking at the highlights). So it's not respecting the ^. See also #11575.

[sandy081]

@erikbra Thanks for reporting.. I will investigate this empty lines case.

[sandy081]

@erikbra You can use regex ^\s*$ also to match empty lines.

Filed #13355 for this particular case.

[erikbra]

Hi.

Thanks for looking into this.

^\s*$ does not do the trick. Instead of doing what I want. It only matches on the first occurence of empty lines. I don't really understand why, but that's what it does.

^\s*$\n does not seem to
respect the ^, as it seems to treat the newline on the previous line as part of the next line (see attached screenshot).

I have attached screenshots from another editor (Sublime, but this is common on all other regex-aware editors) which demonstrates the difference.

Test text used:

søflkjasdlkfj

           asdølfnasdøfln   
dasfsadf

asdfasdfasdf


gasgasdgasdgasd

[erikbra]

Maybe this is the problem? Looks like you do some sort of single/multi-line optimization on regexes? #9051 (comment)

[sandy081]

@erikbra I will have to check and confirm you. Thanks.