On Sun, 27 Aug 2017 10:03:52 -0700, sml...@gmail.com wrote: > 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.
At this stage, something's presence in one of the SYN doesn't mandate that it needs to be present in rakudo. Tagged ticket as RFC. -- Will "Coke" Coleda
