javascript - regexp excluye char -

i trying create regexp has following characteristics.

1. begin {{
2. may contain line breaks , character
3. may not contain }}

example

**this ok.

{{ dog car blue #hello#

this not ok.

{{ dog car blue }} #hello#

i tried regexp:

{{2}([\s\s]*?)[^\{]#hello# 

but returns ok

you need tempered greedy token solution because need first match multicharacter leading delimiter {{ , need match any text other #hello# , {{ (multicharacter sequences). if had negate 1 character, [^{] suffice. not case here.

use

/{{[^#}]*(?:}(?!})[^#}]*|#(?!hellow#)[^#}]*)*#hello#/g 

see regex demo

note unrolled variant of {{(?:(?!}}|#hellow#)[\s\s])*#hello# more readable highly inefficient , more prone catastrophic backtracking issue.

details:

• {{ - matches {{
• [^#}]* - 0+ characters other # , }
• (?:}(?!})[^#}]*|#(?!hellow#)[^#}]*)* - matches 0+ sequences of either
  • }(?!})[^#}]* - } not followed } , followed 1+ characters other # , }
  • | - or
  • #(?!hellow#)[^#}]* - # not followed hello# , followed 1+ characters other # , }
• #hello# - #hello#.