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Note that there was no need to actually create an infix operator, as you can use any code as an infix operator if you surround it with `[&( )]`.

    say $filter «[&(  -> $l, $r { $l and $r }  )]» $source
Golfing it down a bit, the shortest I was able to get was

    say $filter «[&(   &[and]   )]» $source;
The `&[and]` references the infix `and` operator.

I think the reason the following doesn't work that way is that `and` is too thunky.

    say $filter «and» $source;
    say $filter «[and]» $source; # identical to previous line
(Note that `and` is supposed to be thunky, so that isn't a bug.)


I personally would write this:

    sub infix:<l-when-r> -> $_, $r {
      # note that the value to be matched with must be in $_
      # prior to using the `when` keyword.
      # it was done in the signature for conciseness

      $_ when $r
Then the conditions can be code objects, regexes (which are a form of code object in Perl6), or literals. (I tried to get it to work with bare Junctions, but I was unable to get the `«»` part to pass it into the operator.)

It does mean that you have to use `True` rather than `1`.

    my $filter = {
        f2 => True,
        f3 => *.contains('data'),
        f5 => {
            f6 => /data/,
        f10 => * == (0 | 1 | 42), # only match these values
        f11 => 42, # only match something equal to 42

    say $source «l-when-r» $filter;

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