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embed_ruby_code_in_regex

🛠️ Embed Ruby Logic with Code Extensions​

Oniguruma in Ruby allows embedding Ruby snippets inside a pattern with (?{ ... }) and dynamic fragments via (??{ ... }). This lets you build contexts or decisions at match time.

counter = 0
regex = /
  (\w+)(?{ counter += 1 })  # increment for each match
/x

"a b c".scan(regex)
p counter  # => 3

Dynamic pattern generation:

words = %w[foo bar]
regex = /(??{ Regexp.union(words) })baz/
p "foobaz".match?(regex)  # => true