return $keyword
}
+sub whitespace {
+ my ($self, $keyword, $depth) = @_;
+ if (lc $keyword eq 'from') {
+ return ['', "\n"];
+ }
+ return ['', ''];
+}
+
+sub newline { "\n" }
+
+sub indent { ' ' x $_[1] }
+
sub unparse {
- my ($self, $tree) = @_;
+ my ($self, $tree, $depth) = @_;
+
+ $depth ||= 1;
if (not $tree ) {
return '';
}
- elsif (ref $tree->[0]) {
- return join (" ", map $self->unparse ($_), @$tree);
+
+ my $car = $tree->[0];
+ my $cdr = $tree->[1];
+
+ if (ref $car) {
+ return join (" ", map $self->unparse($_), @$tree);
}
- elsif ($tree->[0] eq 'LITERAL') {
- return $tree->[1][0];
+ elsif ($car eq 'LITERAL') {
+ return $cdr->[0];
}
- elsif ($tree->[0] eq 'PAREN') {
- return sprintf '(%s)', join (" ", map $self->unparse($_), @{$tree->[1]});
+ elsif ($car eq 'PAREN') {
+ return '(' . $self->newline .
+ join(' ',
+ map $self->indent($depth) . $self->unparse($_, $depth + 1), @{$cdr})
+ . $self->newline . ')';
}
- elsif ($tree->[0] eq 'OR' or $tree->[0] eq 'AND' or (grep { $tree->[0] =~ /^ $_ $/xi } @binary_op_keywords ) ) {
- return join (" $tree->[0] ", map $self->unparse($_), @{$tree->[1]});
+ elsif ($car eq 'OR' or $car eq 'AND' or (grep { $car =~ /^ $_ $/xi } @binary_op_keywords ) ) {
+ return join (" $car ", map $self->unparse($_), @{$cdr});
}
else {
- return sprintf '%s %s', $self->format_keyword($tree->[0]), $self->unparse ($tree->[1]);
+ my ($l, $r) = @{$self->whitespace($car, $depth)};
+ return sprintf "%s %s$r", $self->format_keyword($car), $self->unparse($cdr);
}
}