do it in parts 

my $pat = q{
^([A-Z]+)$ # $1 global model name
|
( # $2 optional model name
[A-Z]+
)?
(.+)$ # $3 the rest of line
};
my @stack;
while( $input =~ m{$pat}gmsx ){
    my @token;
    if( $1 ){    push @token, ['global_model', $1 ];    }
    if( $2 ){    push @token, [ 'model', $1 ];    }
    if( $3 ){    push @token, [ 'pairs', split /\|/, "$3" ];    }
    push @stack, \@token;
}
use Data::Dump qw/ dd /;
dd( \@stack );
__END__

[download]

Shotgun Re: Count Quoted Words, Re^2: POD style regex for inline HTML elements, marpa scanless, Re: print output from the text file. (marpa scanless dsl calculator), Re^2: Help with regular expression ( m/\G/gc ), JSON parser as a single Perl Regex, Re^2: Help with regular expression, perlfaq6#What good is \G in a regular expression?, RFC: A walkthrough from JSON ABNF to Regexp::Grammars,Re^2: parsing XML fragments (xml log files) with... a regex

In reply to Re: Parse structured text using regex by Anonymous Monk
in thread Parse structured text using regex by trippledubs

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