Perl 6 - 用类来排序数组

有多列数据, 序号, 学校, 课程 … 年份这几列。要如果学校和课程相同就根据年份倒序排列。

先按学校排序, 再按课程排序, 然后按年份倒序排序。

我定义一个类来进行多列数据的排序, 很方便：

class Course {
  has Int $.numb;
  has Str $.univ;
  has Str $.dis;
  has Int $.paper;
  has Int $.cited;
  has Int $.year;
}

my @headers = ;
my @courses;

for $=finish.lines -> $line {
  next if $line ~~ /^num/;
  my @words  = $line.words;
  @words[0, 3,4,5] = @words[0,3,4,5]».Int;
  my %h =  @headers Z=> @words;
  my $course = Course.new(|%h);
  @courses.push($course);
}

my @sorted  = @courses.sort(*.univ).sort(*.dis).sort(-*.year);
for @sorted  {
  say join " ", .numb, .univ, .dis, .paper, .cited, .year;
}

=finish
num univ    dis paper   cited   year
1   Beijing Physics 193 4555    2005
2   Beijing Physics 197 2799    2006
3   Beijing Physics 240 2664    2007
4   Beijing Physics 200 3191    2008
5   Beijing Physics 268 2668    2009
6   Beijing Physics 249 2300    2010
7   Beijing Physics 262 2080    2011
8   Beijing Physics 230 2371    2012
9   Beijing Physics 309 1367    2013
10  Beijing Physics 284 615 2014
11  Beijing Chemistry   143 1650    2005
12  Beijing Chemistry   149 2379    2006
13  Beijing Chemistry   190 2566    2007
14  Beijing Chemistry   147 1888    2008
15  Beijing Chemistry   184 2146    2009
16  Beijing Chemistry   214 2568    2010
17  Beijing Chemistry   238 2874    2011
18  Beijing Chemistry   265 2097    2012
19  Beijing Chemistry   251 1303    2013
20  Beijing Chemistry   241 656 2014