converting generation format to parent child format (recursive)

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

Dear Monks,

Here's a question I'd like to solve in Perl :

Any tips welcome for changing this formating (generation ordered http://download.oracle.com/docs/cd/E12825_01/epm.111/esb_dbag/dotdimb.htm#dotdimb1060220) :

gen2   gen3   gen4   gen5   gen6
A   B   C   D   E

into this one (recursively ordered http://download.oracle.com/docs/cd/E12825_01/epm.111/esb_dbag/dotdimb.htm#dotdimb1060462) :

Parent   Child
   A
A   B
B   C
C   D

My question/problem is how do I "navigate" between tab separated columns using Perl, how getting dynamically next or previous columns ... hmm array is the key it seems but then how to permute making it recursive!

Many thanks for guidance.

SRx

Comment on converting generation format to parent child format (recursive)

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Re: converting generation format to parent child format (recursive) by Util (Priest) on Apr 13, 2011 at 18:19 UTC
I see no permutation or recursion in your example; In what way would this code be insufficient? : `#!/usr/bin/perl use strict; use warnings; while (<DATA>) { chomp; my @fields = split /\s+/; # Change to /\t/ for production? # You can walk the array like this: print "\t$fields[0]\n"; for my $i ( 1 .. $#fields ) { print "$fields[$i-1]\t$fields[$i]\n"; } # Or like this: # my $last_field = ''; # for my $field (@fields) { # print "$last_field\t$field\n"; # $last_field = $field; # } print "\n"; } __DATA__ A B C D E Foo Bar Baz Senior Junior TheThird` [download] Output: `A A B B C C D D E Foo Foo Bar Bar Baz Senior Senior Junior Junior TheThird` [download]	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re: converting generation format to parent child format (recursive)
by Util (Priest) on Apr 13, 2011 at 18:19 UTC

I see no permutation or recursion in your example; In what way would this code be insufficient? :

#!/usr/bin/perl
use strict;
use warnings;

while (<DATA>) {
    chomp;
    my @fields = split /\s+/; # Change to /\t/ for production?


    # You can walk the array like this:
    print "\t$fields[0]\n";
    for my $i ( 1 .. $#fields ) {
        print "$fields[$i-1]\t$fields[$i]\n";
    }
    # Or like this:
#    my $last_field = '';
#    for my $field (@fields) {
#        print "$last_field\t$field\n";
#        $last_field = $field;
#    }


    print "\n";
}

__DATA__
A   B   C   D   E
Foo Bar Baz
Senior  Junior  TheThird
[download]

    A
A   B
B   C
C   D
D   E

    Foo
Foo Bar
Bar Baz

        Senior
Senior  Junior
Junior  TheThird
[download]

[reply]
[d/l]
[select]