add slice stability requirement code

[dbsrgits/Data-Query.git] / lib / Data / Query / ExprBuilder.pm

diff --git a/lib/Data/Query/ExprBuilder.pm b/lib/Data/Query/ExprBuilder.pm
index a1767f1..0c8ee7b 100644 (file)
--- a/lib/Data/Query/ExprBuilder.pm
+++ b/lib/Data/Query/ExprBuilder.pm
@@ -1,6 +1,49 @@
 package Data::Query::ExprBuilder;
 
 use strictures 1;
+use Scalar::Util ();
+use Data::Query::ExprHelpers qw(perl_scalar_value perl_operator);
+
+use overload (
+  # unary operators
+  (map {
+    my $op = $_;
+    $op => sub {
+      Data::Query::ExprBuilder->new({
+        expr => perl_operator($op => $_[0]->{expr})
+      });
+    }
+  } qw(! neg)),
+  # binary operators
+  (map {
+    my ($overload, $as) = ref($_) ? @$_ : ($_, $_);
+    $overload => sub {
+      Data::Query::ExprBuilder->new({
+        expr => perl_operator(
+           $as,
+           map {
+             (Scalar::Util::blessed($_)
+             && $_->isa('Data::Query::ExprBuilder'))
+               ? $_->{expr}
+               : perl_scalar_value($_)
+              # we're called with ($left, $right, 0) or ($right, $left, 1)
+            } $_[2] ? @_[1,0] : @_[0,1]
+          )
+      });
+    }
+  }
+    qw(+ - * / % ** << >> . < > == != lt le gt ge eq ne),
+
+    # since 'and' and 'or' aren't operators we borrow the bitwise ops
+    [ '&' => 'and' ], [ '|' => 'or' ],
+  ),
+  # unsupported
+  (map {
+    my $op = $_;
+    $op => sub { die "Can't use operator $op on a ".ref($_[0]) }
+   } qw(<=> cmp x ^ ~)
+  ),
+); 
 
 sub new {
   bless({ %{$_[1]} }, (ref($_[0])||$_[0]));