Perl 6 implementation of the following Perl 5 code

konnjuta has asked for the wisdom of the Perl Monks concerning the following question:

Problem:

Given list of files delimited by whitespaces and following a format similar to the below example

ID    SOURCE    SCORE1    SCORE2    SCORE3    .....    SCOREN
66521    SRC1        12        34        27            67
88921    SRC2        34        56        59            88
66524    SRC1        56        66    
3341    SRC1        44        59        67
[download]

Print out all SRC1 records in reverse column order delimited by a single space and sorted by the last score then sorted by ID.

Perl 5 (Possible Solution):

print join " ",  reverse split foreach  
    map  { $_->[0] } 
    sort { $a->[1]<=>$b->[1] || $a->[0] <=> $b->[0] } 
    map  { [ $_ , (split)[-1] ] } 
    grep { /SRC1/ } <> ;
[download]

How can I do it in Perl 6?

UPDATE: Here's are possible one-liner solutions thanks to moritz

Functional Approach

say reverse .words for map *[2], sort map {[.words[*-1,0],$_]}, grep /SRC1/, lines;

Object-Oriented Approach

say .words.reverse for lines.grep(/ICSE/).map({[.words[*-1,0],$_]}).sort.map(*[2]);

The Perl 6 syntax is much cleaner.

Comment on Perl 6 implementation of the following Perl 5 code Select or Download Code

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Re: Perl 6 implementation of the following Perl 5 code by moritz (Cardinal) on May 27, 2013 at 11:13 UTC
A solution similar to yours in style: `use v6; print join ' ', reverse .words for lines.grep(/SRC1/)\ .map({ [+<<.words[-1, 0], $_]})\ .sort\ .map([2])` [download] And a version using feeds (note that feeds support in Rakudo is still somewhat lacking and experimental, but this one works:) `use v6; lines() ==> grep(/SRC1/) ==> map({ [+<<.words[-1, 0], $_]}) ==> sort() ==> map([2]) ==> my @lines; print ~.words.reverse for @lines;` [download] And here is another solution: `class Line { has $.str handles 'words'; method Str { self.words.reverse.join(' ') } } multi infix:<cmp>(Line $a, Line $b) { $a.words[-1] <=> $b.words[-1] \|\| $a.words[0] <=> $b.words[0]; } print lines().map({Line.new(str => $_)}).grep(/SRC1/).sort;` [download] (Which admittedly doesn't do the Schwartz Transform). (Update: added second version, tested and fixed third version) Perl 6 - the future is here, just unevenly distributed	[reply] [d/l] [select]
Re^2: Perl 6 implementation of the following Perl 5 code by Jenda (Abbot) on May 27, 2013 at 12:27 UTC
Waitasec?!? What's the backslash at the end of the lines in the first solution? Looks suspiciously like a line continuation character in the worst tradition of Visual Basic and Ruby?!? Jenda Enoch was right! Enjoy the last years of Rome.	[reply]
Re^3: Perl 6 implementation of the following Perl 5 code by duelafn (Parson) on May 27, 2013 at 14:03 UTC
It is "unspace". Whitespace is not allowed before subscripts or ".". Apparently this is required to allow "if" conditions without parens and is part of the "space is sometimes significant" path that was taken. (See: Synopsis 3 and the linked Synopsis 2) Update: Below, moritz clarifies that "if" without parens was not the reason for forbidding whitespace around "." methods calls, merely another of the consequences. Good Day, Dean	[reply]
Re^4: Perl 6 implementation of the following Perl 5 code by BrowserUk (Patriarch) on May 27, 2013 at 14:17 UTC
Re^5: Perl 6 implementation of the following Perl 5 code by moritz (Cardinal) on May 27, 2013 at 15:32 UTC
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Re^5: Perl 6 implementation of the following Perl 5 code by hdb (Monsignor) on May 27, 2013 at 14:28 UTC
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Re^5: Perl 6 implementation of the following Perl 5 code by ww (Archbishop) on May 27, 2013 at 15:23 UTC
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Re^2: Perl 6 implementation of the following Perl 5 code by konnjuta (Acolyte) on May 28, 2013 at 00:34 UTC
The 1st/2nd Perl 6 solution is interesting because you read it from left to right treating map,grep and sort as object methods. The Perl 5 version is read from right to left treating map,grep and sort as functions. I've attempted to do it the functional way in Perl 6 and got the following to work on Rakudo. `use v6; say reverse .words for map {.[1]} ,sort( map { [.words[*-1],$_] } ,grep {/SRC1/} ,lines() );` [download] The syntax for doing Perl 6 functionally seems to be more untidy than the Perl 5 version and make it a bit harder to read. The required comma, the required parenthesis around sort. Its not too bad though. Will get some getting use to.	[reply] [d/l]
Re^3: Perl 6 implementation of the following Perl 5 code by moritz (Cardinal) on May 28, 2013 at 05:26 UTC
If you make the commas stand out by putting them up front, it looks untidy, yes. As they say, the key is to play to Perl's strengths, not to its weaknesses. And if you include unnecessary punctuation, it also looks untidy. This one seems to work fine: `use v6; say reverse .words for map [1], sort map { [.words[-1],$_] }, grep /SRC1/, lines;` [download] Perl 6 - the future is here, just unevenly distributed	[reply] [d/l]
Re^4: Perl 6 implementation of the following Perl 5 code by konnjuta (Acolyte) on May 28, 2013 at 07:23 UTC