Regular Expressions 101

Pro

Group 1( \( # Match all but characters `\`, `(` or `)` (?> [^\\()] | \\. | (?1) )* \) )

\(the literal ( (40₁₀ / 50₈ / 28₁₆)

Comment: Match all but characters `\`, `(` or `)`

Atomic Group(?> [^\\()] | \\. | (?1) )*

*repeats the group contents below any number of times:

1st Alternative [^\\()]

Negated Character Class[^\\()]

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

(the literal ( (40₁₀ / 50₈ / 28₁₆)

)the literal ) (41₁₀ / 51₈ / 29₁₆)

2nd Alternative \\.

\\the literal \ (92₁₀ / 134₈ / 5C₁₆)

.any character (except for line terminators)

3rd Alternative (?1)

(?1)calls group 1 as a subroutine

\)the literal ) (41₁₀ / 51₈ / 29₁₆)

Global pattern flags

g modifier: global. Finds all matches instead of stopping after the first

x modifier: extended. Ignores unescaped whitespace and comments outside character classes

Detailed match information will be displayed here automatically.

25 tokens

(
  \(
  # Match all but characters `\`, `(` or `)`
  (?> [^\\()]
  |   \\.
  |   (?1)
  )*
  \)
)

New

SHOULD MATCH:
()
(())
((()))
(\()  (\))
(\(\)\)\)\))

SHOULD NOT MATCH:
)
(
((((\)\)\)\)

SHOULD MATCH:
()
(())
((()))
(\()  (\))
(\(\)\)\)\))

SHOULD NOT MATCH:
)
(
((((\)\)\)\)