( x = ? OR ( y = ? OR z = ? ) OR key = ? OR lit() )
[ 1, 2, 3, 'value' ]
+=head1 Default Expanders
+
+=head2 bool
+
+Turns the old -bool syntax into the value expression, i.e.
+
+ # expr
+ { -bool => { -ident => 'foo' } }
+
+ # aqt
+ { -ident => [ 'foo' ] }
+
+ # query
+ foo
+ []
+
+behaves the same way as the now-directly-supported
+
+ # expr
+ { -ident => 'foo' }
+
+ # aqt
+ { -ident => [ 'foo' ] }
+
+ # query
+ foo
+ []
+
+=head2 row
+
+Expands the elements of the value arrayref:
+
+ # expr
+ { -row => [ 1, { -ident => 'foo' }, 2, 3 ] }
+
+ # aqt
+ { -row => [
+ { -bind => [ undef, 1 ] }, { -ident => [ 'foo' ] },
+ { -bind => [ undef, 2 ] }, { -bind => [ undef, 3 ] },
+ ] }
+
+ # query
+ (?, foo, ?, ?)
+ [ 1, 2, 3 ]
+
+=head2 op
+
+If an expander is registered for the op name, delegates to the expander; if
+not, expands the argument values:
+
+ # expr
+ { -op => [ 'ident', 'foo.bar' ] }
+
+ # aqt
+ { -ident => [ 'foo', 'bar' ] }
+
+ # query
+ foo.bar
+ []
+
+ # expr
+ { -op => [ '=', { -ident => 'foo' }, 3 ] }
+
+ # aqt
+ { -op => [ '=', { -ident => [ 'foo' ] }, { -bind => [ undef, 3 ] } ] }
+
+ # query
+ foo = ?
+ [ 3 ]
+
=cut