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~$ raku -e 'my regex H { "======" <alpha>**3 "======" \v };  \
            my @a = slurp.comb( / <H> [ \V+ \v]+? <?before <H> | $ > /).pairs;  \
            .raku.put for flat @a[0..1,(2..3).sort.reverse,4..*];'  file
0 => "======abc======\ndata1\ndata2\ndata3\n"
1 => "======def======\ndata4\n"
3 => "======jkl======\ndata7\n"
2 => "======ghi======\ndata5\ndata6\n"
4 => "======mno======\ndata8\n"

#OR (another way of flattening):

~$ raku -e 'my regex H { "======" <alpha>**3 "======" \v };  \
            my @a = slurp.comb( / <H> [ \V+ \v]+? <?before <H> | $ > /).pairs;  \
            .raku.put for @a[flat(0..1;(2..3).sort.reverse;[email protected])];'  file
0 => "======abc======\ndata1\ndata2\ndata3\n"
1 => "======def======\ndata4\n"
3 => "======jkl======\ndata7\n"
2 => "======ghi======\ndata5\ndata6\n"
4 => "======mno======\ndata8\n"

~$ raku -e 'my regex H { "======" <alpha>**3 "======" \v };  \
            my @a = slurp.comb( / <H> [ \V+ \v]+? <?before <H> | $ > /).pairs;  \
            .raku.put for flat @a[0..1,(2..3).sort.reverse,4..*];'  file
0 => "======abc======\ndata1\ndata2\ndata3\n"
1 => "======def======\ndata4\n"
3 => "======jkl======\ndata7\n"
2 => "======ghi======\ndata5\ndata6\n"
4 => "======mno======\ndata8\n"

#OR (flattening by a different method):

~$ raku -e 'my regex H { "======" <alpha>**3 "======" \v };  \
            my @a = slurp.comb( / <H> [ \V+ \v]+? <?before <H> | $ > /).pairs;  \
            .raku.put for @a[flat(0..1;(2..3).sort.reverse;[email protected])];'  file
0 => "======abc======\ndata1\ndata2\ndata3\n"
1 => "======def======\ndata4\n"
3 => "======jkl======\ndata7\n"
2 => "======ghi======\ndata5\ndata6\n"
4 => "======mno======\ndata8\n"

~$ raku -e 'my @a = slurp.comb( / "======" (<alpha>**3) "======" \v [ \V+ \v]+? <?before "======" | $ > /);  \
            .print for flat @a[0..1,(2..3).sort.reverse,4..*];'  file

~$ raku -e 'my regex H { "======" <alpha>**3 "======" \v };  \
            my @a = slurp.comb( / <H> [ \V+ \v ]+? <?before <H> | $ > /);  \
            .print for flat @a[0..1,(2..3).sort.reverse,4..*]'  file

~$ raku -e 'my regex H { "======" <alpha>**3 "======" \v };  \
            my @a = slurp.comb( / <H> [ \V+ \v]+? <?before <H> | $ > /).pairs;  \
            .raku.put for flat @a[0..1,(2..3).sort.reverse,4..*];'  file
0 => "======abc======\ndata1\ndata2\ndata3\n"
1 => "======def======\ndata4\n"
3 => "======jkl======\ndata7\n"
2 => "======ghi======\ndata5\ndata6\n"
4 => "======mno======\ndata8\n"

~$ raku -e 'my @a = slurp.comb( / "======" (<alpha>**3) "======" \v [ \V+ \v]+? <?before "======" | $ > /);  \
            .print for flat @a[0..1,(2..3).sort.reverse,4..*];'  file

~$ raku -e 'my regex H { "======" <alpha>**3 "======" \v };  \
            my @a = slurp.comb( / <H> [ \V+ \v ]+? <?before <H> | $ > /);  \
            .print for flat @a[0..1,(2..3).sort.reverse,4..*]'  file

~$ raku -e 'my regex H { "======" <alpha>**3 "======" \v };  \
            my @a = slurp.comb( / <H> [ \V+ \v]+? <?before <H> | $ > /).pairs;  \
            .raku.put for flat @a[0..1,(2..3).sort.reverse,4..*];'  file
0 => "======abc======\ndata1\ndata2\ndata3\n"
1 => "======def======\ndata4\n"
3 => "======jkl======\ndata7\n"
2 => "======ghi======\ndata5\ndata6\n"
4 => "======mno======\ndata8\n"

#OR (another way of flattening):

~$ raku -e 'my regex H { "======" <alpha>**3 "======" \v };  \
            my @a = slurp.comb( / <H> [ \V+ \v]+? <?before <H> | $ > /).pairs;  \
            .raku.put for @a[flat(0..1;(2..3).sort.reverse;[email protected])];'  file
0 => "======abc======\ndata1\ndata2\ndata3\n"
1 => "======def======\ndata4\n"
3 => "======jkl======\ndata7\n"
2 => "======ghi======\ndata5\ndata6\n"
4 => "======mno======\ndata8\n"

NOTE: When re-arranging [ … ] indices within an @-sigiled array, it is very important to flatten the resulting sequence and/or object, since Raku (unlike Perl) does not auto-flatten by default.

NOTE: When re-arranging [ … ] indices within an @-sigiled array, it is very important to flatten the resulting sequence and/or object, since Raku (unlike Perl) does not auto-flatten by default.