Anytime you can say "I want my data arranged so that...", all you need to do is find the comparison subroutine that expresses what you said. Since this isn't a standard routine, you're right, it has to be "scratch-written".

Of course, on occasion, the subroutine will need a bit of helper data. In this case, we need a mapping of days of month -> sort ordering. 

# the initial array
my @AOH=(
   {dayOfMonth=>19, clockReading=>02},
   {dayOfMonth=>21, clockReading=>12},
   {dayOfMonth=>15, clockReading=>04},
   {dayOfMonth=>19, clockReading=>05},
   {dayOfMonth=>15, clockReading=>23},
   {dayOfMonth=>19, clockReading=>12}
);

# here's where you specify the ordering for the days of the
# month...
my %dayOfMonthMap=(
   21 => 1,
   17 => 2,
   14 => 3,
   15 => 4,
#...
   19 => 21, # let's say
);

# For speed, let's remap that to an array, with the index
# being the day of the month
my @dayOfMonthRemap;
foreach(keys %dayOfMonthMap) {
    $dayOfMonthRemap[$_]=$dayOfMonthMap{$_};
}

#ok, now we're ready to sort!
my @sortedArray=sort {
                        # if it's the same day, the || will make
                        # this compare by clockReading
                        $dayOfMonthRemap[$a->{dayOfMonth}] <=> $dayOfM
+onthRemap[$b->{dayOfMonth}] ||
                        $a->{clockReading} <=> $b->{clockReading}
                     } @AOH;

# Let's print out the result to make sure it's sane...
foreach(@sortedArray) {
    print "$_->{dayOfMonth} : $_->{clockReading}\n";
}

[download]

--
Mike

In reply to Re: Sorting into a Specific Order by RMGir
in thread Sorting into a Specific Order by Anonymous Monk

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.