Note that in Perl 6 => constructs a Pair, it's not the same as a comma.

Assuming that you have a flat list, and not a list of pairs, it'll look like this in diplomatic idiomatic Perl 6: 

my $in = [ one => 1, two => 2, two => '2.003' ];
my %h;

for @$in -> $k, $v {
    %h{$k}.push: $v;
}

[download]

(not golfed).

Rakudo doesn't support this kind of autovivification yet, so the .push on the empty hash bucket fails. However this works in Rakudo: 

use v6;

my $in = [ 'one', 1, 'two', 2, 'two', '2.003' ];
my %h;

for @($in) -> $k, $v {
    if %h{$k} {
        %h{$k}.push: $v;
    } else {
        %h{$k} = [ $v ];
    }
}

say %h.perl;

# output:
# {"one" => [1], "two" => [2, "2.003"]}

[download]

if $in is an Array of pairs instead, you can loop over them, and access .key and .value (a method call with a leading dot but no invocant defaults to $_): 

use v6;

my $in = [ one => 1, two => 2, two => '2.003' ];
my %h;

for @($in) {
    if %h{.key} {
        %h{.key}.push: .value;
    } else {
        %h{.key} = [ .value ];
    }
}

say %h.perl;

# vim: ft=perl6 sw=4 ts=4 expandtab
# same output

[download]

Again, a complete Perl 6 implementation would allow it shorter like this: 

%h{.key}.push: .value for @$in:

[download]

Even nicer, but also not yet implement is 

my %h = $in.classify: { $_ };

[download]

See the documentation of classify for more information.

Update: A nicer way to write the first loop is 

for @($in) -> $k, $v {
    %h{$k} //= [];
    %h{$k}.push: $v;
}

[download]

In reply to Re: my array is almost a hash, but keys are not unique. (Perl 6) by moritz
in thread my array is almost a hash, but keys are not unique. by Boldra

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.