Rules / Types, classes & roles / composite

Slip Reference

A kind of List that automatically flattens into an outer container

What it is #

Routines #

Signatures are reproduced from the documentation, including their declared return types. A routine listed here is part of the type's published interface; whether Raku++ implements it is a separate question, answered by the examples below.

method List #

multi method List(Slip:D: --> List:D)

Returns List:D.

Turns it into a list.

sub slip #

multi slip(--> Empty)
multi slip(@args --> Slip:D)
multi slip(+args --> Slip:D)

Returns Empty or Slip:D.

Creates a Slip from its arguments by calling .Slip on the object formed by them. Returns Empty if called with void arguments.

Examples, run three ways #

Every example below comes from the official documentation, together with the output that documentation asserts. Each was then executed by Rakudo and by Raku++ when this page was built. Where the three agree, one result is shown; where they do not, all three are — because which of them is wrong is exactly the information worth having.

4 no-output · 4 ok

class Slip is List {}

Not executed: the documentation states no expected output for this example.

say <a b c>.map({ ($_, $_.uc).Slip }).join('|');        # OUTPUT: «a|A|b|B|c|C␤»
Output
a|A|b|B|c|C

Documentation, Rakudo and Raku++ all agree.

say <a b c>.map({ $_, $_.uc }).join('|');               # OUTPUT: «a A|b B|c C␤»
Output
a A|b B|c C

Documentation, Rakudo and Raku++ all agree.

# This says "1" and then says "2", rather than saying "(1 2)"
.say for gather {
    take slip(1, 2);
}

Not executed: the documentation states no expected output for this example.

my $l = (1, 2, 3);
say (1, slip 2, 3).raku;  # says (1, 2, 3)          , slips 2, 3 into (1, …)
say (0, slip $l, 4).raku; # says (0, $(1, 2, 3), 4) , $l does not break apart
say (0, slip $l).raku;    # says (0, 1, 2, 3)       , slips from $l into (0, …)
say (0, $l.Slip).raku;    # says (0, 1, 2, 3)       , slips from $l into (0, …)
say (0, $l.Slip, 4).raku; # says (0, 1, 2, 3, 4)    , slips from $l into (0, …, 4)
say (|$l).raku;           # says slip(1, 2, 3)      , breaks apart $l
say (0, (|$l, 4), 5);     # says (0 (1 2 3 4) 5)    , slips from $l into (…, 4)
say (0, ($l.Slip, 4), 5); # says (0 (1 2 3 4) 5)    , slips from $l into (…, 4)
say (0, (slip $l, 4), 5); # says (0 (1 2 3) 4 5)    , slips ($l, 4) into (0, …, 5)
say (0, ($l, 4).Slip, 5); # says (0 (1 2 3) 4 5)    , slips ($l, 4) into (0, …, 5)

Not executed: the documentation states no expected output for this example.

my \l = gather for 1..10 -> $a, $b { take |($a, $b) }; say l.raku;
# OUTPUT: «((1, 2), (3, 4), (5, 6), (7, 8), (9, 10)).Seq␤»
my \m= gather for 1..10 -> $a, $b { take ($a, $b).Slip }; say m.raku;
# OUTPUT: «(1, 2, 3, 4, 5, 6, 7, 8, 9, 10).Seq␤»
Output
((1, 2), (3, 4), (5, 6), (7, 8), (9, 10)).Seq
(1, 2, 3, 4, 5, 6, 7, 8, 9, 10).Seq

Documentation, Rakudo and Raku++ all agree.

say "".comb ~~ Empty;
# OUTPUT: «True␤»
Output
True

Documentation, Rakudo and Raku++ all agree.

do if 0 {};
(42 if 0);
do with Any {};
(42 with Any);

Not executed: the documentation states no expected output for this example.