Re: Recursive subroutines with sort

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Re^2: Recursive subroutines with sort by choroba (Cardinal) on Jul 08, 2019 at 10:52 UTC
I've investigated the deltas because of Syntax::Construct and it seemed it had been possible to use recursive subroutines in older Perls, too. 5.10 was just the version that documented the fact. `map{substr$_->[0],$_->[1]\|\|0,1}[\\|\|{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^ARGV,3]`	[reply] [d/l]
Re^2: Recursive subroutines with sort by holli (Abbot) on Jul 08, 2019 at 10:16 UTC
Hah. I didn't know that. I have exclusively used the BLOCK form to this date. It's nice being able to refer to a sub by name, but when is it useful that sub being able to recurse? holli You can lead your users to water, but alas, you cannot drown them.	[reply] [d/l]
Re^3: Recursive subroutines with sort by LanX (Saint) on Jul 08, 2019 at 12:46 UTC
> but when is it useful that sub being able to recurse? what comes to mind are chained comparisons in `sort` ° `sort { $a->[0] cmp $b->[0] or $a->[1] cmp $b->[1] # * or $a->[2] cmp $b->[2] # * or ... # * } @AoA # *) only check if former was equal == 0 == false` [download] if you don't know the number of fields, recursive comparisons come in handy. I'm bu-la-zy, so constructing the recursion is left as exercise. ;-) HTH! update In hindsight ... this particular case could also be solved in a loop. So think about a more complicated data structures like trees to be sorted. In the end it's about convenience ... every loop can be expressed as recursion and vice versa. Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery FootballPerl is like chess, only without the dice} °) see examples in code from line 39 onwards	[reply] [d/l]

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