You could decouple the parsing and building steps, as
nothingmuch suggested:
sub parse_brackets {
my @out;
foreach my $line ( @_ ) {
$line_no ++;
$line =~ s/\A\s+//;
$line =~ s/\s+\Z//;
if ( $line !~ /\S/ ) {
next;
} elsif ( $line =~ s/\s*\{$// ) {
push @out, 'open' => [ split ' ', $line ];
} elsif ( $line eq '}' ) {
push @out, 'close' => 1;
} else {
push @out, 'line' => $line;
}
}
return @out;
}
sub build_brackets {
my @parse;
my @stack = \@parse;
while ( scalar @_ ) {
my ( $type, $value ) = splice( @_, 0, 2 );
if ( $type eq 'open' ) {
my %node = ( type => shift(@$value), ( @$value ? ( name => shift
+(@$value) ) : () ) );
push @{ $stack[0] }, \%node;
unshift @stack, do { $node{contents} = [] };
} elsif ( $type eq 'close' ) {
shift @stack;
scalar @stack or die("Too many right brackets");
} else {
push @{ $stack[0] }, $value;
}
}
scalar @stack == 1 or die("Too few right brackets");
return @parse;
}
use Data::Dumper;
print Dumper( build_brackets( parse_brackets( @lines ) ) );
I'm not sure this is a big win for your case, but if you need the extra flexiblity...