Backtrack explicitly across an optional namespace prefix - #14
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The optional prefix ident matches the `url` of `url(...)`, and the rule only parses because it then backtracks to give the prefix up. That only works because a quantifier followed by whitespace in a rule is currently not ratcheted, which rakudo may change in the future. `?!` asks for the backtracking explicitly, so the rule keeps parsing either way.
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The optional prefix ident matches the
urlofurl(...), and the rule only parses because it then backtracks to give the prefix up. That only works because a quantifier followed by whitespace in a rule is currently not ratcheted, which rakudo may change in the future.?!asks for the backtracking explicitly, so the rule keeps parsing either way.