ietf-mta-filters
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Re: {} in if/else

1997-11-06 10:20:08
Tim Showalter <tjs(_at_)andrew(_dot_)cmu(_dot_)edu> writes:
What happens in this script --

if false keep; else if false fileinto "foo"; else trash

  trash.  You only run into ambiguities if you can write things like

    if false if false fileinto "foo"; else trash

  where it's not clear which "if" the else belongs to.

  (The problem is that if-then-else is hard to specify unambiguously
in a context-free grammar (although it's certainly possible).  In
practice, though, it tends to work fine - yacc, for instance, will
complain about the shift/reduce conflict, but will default to shifting
the else token, which is exactly what should happen.)

  )Rob

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