# New Ticket Created by Sam S. # Please include the string: [perl #131973] # in the subject line of all future correspondence about this issue. # <URL: https://rt.perl.org/Ticket/Display.html?id=131973 >
Based on S05, these test-cases should all pass: is "ab" ~~ / [ab | a ] b /, "ab", 'normal backtracking'; is "ab" ~~ / [ab | a ]: b /, Nil, 'locally disabled backtracking'; is "ab" ~~ / :r [ab | a ] b /, Nil, 'globally disabled backtracking'; is "ab" ~~ / :r [ab | a ]:! b /, "ab", 'globally disabled but locally re-enabled backtracking'; In current Rakudo, the first three pass but the last one fails (it refuses to backtrack into the alternation and thus returns no Match). According to S05 that's a bug: "The new :r or :ratchet modifier causes this regex to not backtrack by default. [...] Explicit backtracking modifiers on quantified atoms[...] will override this. -- http://design.perl6.org/S05.html#line_624 Related to RT #130117.