my @delim = ( ["A", -3, "C"], ["C", -4, "B"] );
my @data  = (
  ["A", -4, "A"],
  ["A", -1, "C"],
  ["C", -4, "D"],
  ["D", -4, "B"],
  ["B", -3, "C"],
  ["C", -2, "B"],
  ["B", -1, "E"]
);

##</code><code>##

#!/usr/bin/perl -l
use Algorithm::Loops 'NestedLoops';

my @delim = ...
my @data  = ...

my $N = $#data;
my $D = $#delim;

NestedLoops(
  [        [0    .. $N],  sub {[$_ .. $N]},
    ( sub {[$_+1 .. $N]}, sub {[$_ .. $N]} ) x $D
  ],
  { OnlyWhen => sub {
       return 0 if @_ < 2*@delim;
       for my $d (0 .. $D) {
         return 0 if $data[ $_[ $d*2     ] ][0] ne $delim[$d][0]
                  or $data[ $_[ $d*2 + 1 ] ][2] ne $delim[$d][2]
       }
       return 1;
  } },
  sub {
    my @ranges = map { [@data[ $_[2*$_] .. $_[2*$_+1] ]] } 0 .. $D;
    print join " / ",
          map { my $range = $_; join " ", map "[@$_]", @$range } @ranges;
  }
);

##</code><code>##

NestedLoops(
  [        [0    .. $N],  sub {[$_ .. $N]},
    ( sub {[$_+1 .. $N]}, sub {[$_ .. $N]} ) x $D
  ],

##</code><code>##

for my $i0 ( 0 .. $N ) {
  for my $i1 ( $i0 .. $N ) {
    for my $i2 ( $i1+1 .. $N ) {
      for my $i3 ( $i2 .. $N ) {
        ...

##</code><code>##

  { OnlyWhen => sub {
       return 0 if @_ < 2*@delim;
       for my $d (0 .. $D) {
         return 0 if $data[ $_[ $d*2     ] ][0] ne $delim[$d][0]
                  or $data[ $_[ $d*2 + 1 ] ][2] ne $delim[$d][2]
       }
       return 1;
  } },

##</code><code>##

  sub {
    my @ranges = map { [@data[ $_[2*$_] .. $_[2*$_+1] ]] } 0 .. $D;
    print join " / ",
          map { my $range = $_; join " ", map "[@$_]", @$range } @ranges;
  }

##</code><code>##

[A -4 A] [A -1 C] / [C -4 D] [D -4 B]
[A -4 A] [A -1 C] / [C -4 D] [D -4 B] [B -3 C] [C -2 B]
[A -4 A] [A -1 C] / [C -2 B]
[A -4 A] [A -1 C] [C -4 D] [D -4 B] [B -3 C] / [C -2 B]
[A -1 C] / [C -4 D] [D -4 B]
[A -1 C] / [C -4 D] [D -4 B] [B -3 C] [C -2 B]
[A -1 C] / [C -2 B]
[A -1 C] [C -4 D] [D -4 B] [B -3 C] / [C -2 B]

##</code><code>##

my @intervals = NestedLoops(
  ..
  sub {
    return [ map { [@data[ $_[2*$_] .. $_[2*$_+1] ]] } 0 .. $D ]
  }
);