Matching multiline regex in Sublime Text

Question

I was tried to write regex in Sublime Text that find three match in

A1
A2
A3
B1
B2
B3
C1
C2
C3

1 match

A1
A2
A3

2 match

B1
B2
B3

3 match

C1
C2
C3

Of course, It can be handled with for example

((?:A\d\n)+|(?:B\d\n)+|(?:C\d\n)+)

Is there more smart approach to do it instead of just enumerating?

Interactive demo

Answer 1

You may use

^([A-Z])\d+(?:\R\1\d+)*

See the PCRE regex demo (SublimeText3 uses PCRE regex engine).

Details

• ^ - start of a line
• ([A-Z]) - Group 1: any ASCII uppercase letter (just note that if Case sensitive option is off, this will also match lowercase letters)
• \d+ - 1+ digits
• (?:\R\1\d+)* - zero or more repetitions of:
  • \R - a line break
  • \1 - the same letter as in Group 1
  • \d+ - 1+ digits

Answer 2

Try this pattern: ([A-Z])\d\n\1\d\n\1\d.

Demo