my $all_known_re = join("\n\t|\n",
$expr_start_re,
$binary_op_re,
- "$op_look_behind (?i: AND|OR|NOT ) $op_look_ahead",
- (map { quotemeta $_ } qw/, ( ) */),
+ "$op_look_behind (?i: AND|OR|NOT|\\* ) $op_look_ahead",
+ (map { quotemeta $_ } qw/, ( )/),
$placeholder_re,
);
# FIXME - terrible name for a user facing API
sub unparse {
my ($self, $tree, $bindargs) = @_;
+ $self->_parenthesis_unroll($tree);
$self->_unparse($tree, [@{$bindargs||[]}], 0);
}
}
}
+# All of these keywords allow their parameters to be specified with or without parenthesis without changing the semantics
+my @unrollable_ops = (
+ 'ON',
+ 'WHERE',
+ 'GROUP \s+ BY',
+ 'HAVING',
+ 'ORDER \s+ BY',
+);
+my $unrollable_ops_re = join ' | ', @unrollable_ops;
+$unrollable_ops_re = qr/$unrollable_ops_re/xi;
+
+sub _parenthesis_unroll {
+ my $self = shift;
+ my $ast = shift;
+
+ #return if $self->parenthesis_significant;
+ return unless (ref $ast and ref $ast->[1]);
+
+ my $changes;
+ do {
+ my @children;
+ $changes = 0;
+
+ for my $child (@{$ast->[1]}) {
+ # the current node in this loop is *always* a PAREN
+ if (not ref $child or not $child->[0] eq 'PAREN') {
+ push @children, $child;
+ next;
+ }
+
+ # unroll nested parenthesis
+ while ( @{$child->[1]} && $child->[1][0][0] eq 'PAREN') {
+ $child = $child->[1][0];
+ $changes++;
+ }
+
+ # if the parenthesis are wrapped around an AND/OR matching the parent AND/OR - open the parenthesis up and merge the list
+ if (
+ ( $ast->[0] eq 'AND' or $ast->[0] eq 'OR')
+ and
+ $child->[1][0][0] eq $ast->[0]
+ ) {
+ push @children, @{$child->[1][0][1]};
+ $changes++;
+ }
+
+ # if the parent operator explcitly allows it nuke the parenthesis
+ elsif ( $ast->[0] =~ $unrollable_ops_re ) {
+ push @children, $child->[1][0];
+ $changes++;
+ }
+
+ # only *ONE* LITERAL or placeholder element
+ elsif (
+ @{$child->[1]} == 1 && (
+ $child->[1][0][0] eq 'LITERAL'
+ or
+ $child->[1][0][0] eq 'PLACEHOLDER'
+ )
+ ) {
+ push @children, $child->[1][0];
+ $changes++;
+ }
+
+ # only one element in the parenthesis which is a binary op
+ # and has exactly two grandchildren
+ # the only time when we can *not* unroll this is when both
+ # the parent and the child are mathops (in which case we'll
+ # break precedence) or when the child is BETWEEN (special
+ # case)
+ elsif (
+ @{$child->[1]} == 1
+ and
+ $child->[1][0][0] =~ SQL::Abstract::Tree::_binary_op_re()
+ and
+ $child->[1][0][0] ne 'BETWEEN'
+ and
+ @{$child->[1][0][1]} == 2
+ and
+ ! (
+ $child->[1][0][0] =~ SQL::Abstract::Tree::_math_op_re()
+ and
+ $ast->[0] =~ SQL::Abstract::Tree::_math_op_re()
+ )
+ ) {
+ push @children, $child->[1][0];
+ $changes++;
+ }
+
+ # a function binds tighter than a mathop - see if our ancestor is a
+ # mathop, and our content is:
+ # a single non-mathop child with a single PAREN grandchild which
+ # would indicate mathop ( nonmathop ( ... ) )
+ # or a single non-mathop with a single LITERAL ( nonmathop foo )
+ # or a single non-mathop with a single PLACEHOLDER ( nonmathop ? )
+ elsif (
+ @{$child->[1]} == 1
+ and
+ @{$child->[1][0][1]} == 1
+ and
+ $ast->[0] =~ SQL::Abstract::Tree::_math_op_re()
+ and
+ $child->[1][0][0] !~ SQL::Abstract::Tree::_math_op_re
+ and
+ (
+ $child->[1][0][1][0][0] eq 'PAREN'
+ or
+ $child->[1][0][1][0][0] eq 'LITERAL'
+ or
+ $child->[1][0][1][0][0] eq 'PLACEHOLDER'
+ )
+ ) {
+ push @children, $child->[1][0];
+ $changes++;
+ }
+
+
+ # otherwise no more mucking for this pass
+ else {
+ push @children, $child;
+ }
+ }
+
+ $ast->[1] = \@children;
+
+ } while ($changes);
+
+}
+
sub format { my $self = shift; $self->unparse($self->parse($_[0]), $_[1]) }
1;