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Re: junctions and parenthesis

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Tobias Boege
June 22, 2020 19:14
Re: junctions and parenthesis
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On Mon, 22 Jun 2020, Joseph Brenner wrote:
> Patrick R. Michaud <> wrote:
> > The "any" function is just like any other function taking an arbitrary list
> > of arguments (including user-defined functions).  As such it parses with
> > lower precedence than comparison operators -- so "eq" binds more tightly
> > than "any".
> Thanks, makes sense.
> > I'm not exactly sure what sort of warning should go here, or how it'd be
> > detected.
> Yes, exactly.  From one point of view it's working as designed-- to me
> it felt pretty weird, though.
> Speculating wildly:  could there be a need for a different type of
> function with different precedence?

You can achieve this today by redefining &any to be a prefix operator
and provide it with tight enough precedence. In this example, I pick
infix multiplication as the argument stopper, which is in particular
tighter than the relevant eq operator; your mileage may vary:

  sub old-any (|c) { CORE::{'&any'}.(|c) }

  multi prefix:<any> (|c) is tighter(&infix:<*>) {
      old-any |c

  say so any <a b c> eq any <c d>;            # True (fixed)
  say so old-any(<a b c>) eq old-any(<c d>);  # True
  say so old-any <a b c>  eq old-any <c d>;   # False

Now I'd be interested to see how someone would turn this into a
frugal-sub declarator or an `is frugal` trait.


"There's an old saying: Don't change anything... ever!" -- Mr. Monk

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