Damian Conway wrote:

So I'm going to go on to propose that we create a fifth class of
Junction: the "transjunction", with corresponding keyword C<every>.
say (^10 G[<] one(3,7));
3 4 5 6

which could also be:

    say every(^10) < one(3,7);
    # Every value up to 10 that's greater than 3 or 7 but not both
I just think those all read much better than the (otherwise excellent)
meta-operator. In much the same way that the existing junctive types
read better than their functional or operator-oriented alternatives.

I think that the two proposals are equivalent, in the sense that either can be trivially implemented using the other. So it is indeed a question of which one reads better and fits in better. And I agree, your C<every> proposal does read better (at least to an English speaker).

However, I am a little concerned that the transjunction "magically" changes an operator that returns a Boolean value into one that returns a list. If the usage of a transjuction is non-local to its creation then this could result in surprises, and hence frustrating debugging sessions.

If I wanted to write intentionally confusing code (which sometimes happens due to carelessness) then I might take advantage of the fact that C<every> is, in English, a synonym for C<all>, not C<any>:

  if every(@values) < one(3..7) {...}

I'd like these in the core language (for performance and universal
accessibility), but if not, I already have a nearly-complete
implementation of a module implementing them, which runs successfully on
the current release of Rakudo*. I append said model for your amusement
(and suggestions!).



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