in reply to Perl not BNF-able??

On that note, I would like to ask a related question.

Will Perl6 be BNF-able?

I seem to recall reading somewhere that eventually all perl6 parsing will be implemented in perl6, using one (monster) perl6 rule.

Is that right or borked?

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Re^2: Perl not BNF-able??
by merlyn (Sage) on Jul 01, 2005 at 14:56 UTC
    In a recent conversation with TheDamian, he admitted that Perl6's goal of being able to be lexed and parsed separately was unrealistic. Perl6 will therefore inherit Perl5's necessity of a tight coupling between the lexer and the parser. Oh well.

    -- Randal L. Schwartz, Perl hacker
    Be sure to read my standard disclaimer if this is a reply.

[reply]
      Perl6 will therefore inherit Perl5's necessity of a tight coupling between the lexer and the parser. Oh well.

      We do at least have an explicit parser/lexer system to play with in Perl 6, which should enable us to more easily write Perl programs that parse Perl.

[reply]
Re: Perl not BNF-able??
by jonadab (Parson) on Jul 02, 2005 at 22:27 UTC
    Will Perl6 be BNF-able?

    Not on your life. In Perl6 you can rewrite the very grammar of the language ("All's fair if you predeclare"), and there's absolutely no way BNF can handle that.

    "In adjectives, with the addition of inflectional endings, a changeable long vowel (Qamets or Tsere) in an open, propretonic syllable will reduce to Vocal Shewa. This type of change occurs when the open, pretonic syllable of the masculine singular adjective becomes propretonic with the addition of inflectional endings."  — Pratico & Van Pelt, BBHG, p68
[reply]

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