From 50a445f82ffb83bfee63ab1381c891d87d873245 Mon Sep 17 00:00:00 2001
From: Gregory Todd Williams <greg@evilfunhouse.com>
Date: Fri, 12 Feb 2016 10:20:57 -0800
Subject: [PATCH] Fix Attean::Algebra::Update->blank_nodes (#70).

---
 lib/Attean/Algebra.pm | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/lib/Attean/Algebra.pm b/lib/Attean/Algebra.pm
index 2e854887..789ff612 100644
--- a/lib/Attean/Algebra.pm
+++ b/lib/Attean/Algebra.pm
@@ -1403,6 +1403,19 @@ package Attean::Algebra::Update 0.012 {
 		}
 	}
 	
+	around 'blank_nodes' => sub {
+		my $orig	= shift;
+		my $self	= shift;
+		my @blanks	= $orig->($self, @_);
+		my %seen	= map { $_->value => 1 } @blanks;
+		foreach my $data ($self->insert, $self->delete) {
+			my @triples	= @{ $data };
+			my @b	= grep { $_->does('Attean::API::Blank') } map { $_->values } @triples;
+			push(@blanks, grep { not $seen{$_->value}++ } @b);
+		}
+		return @blanks;
+	};
+	
 	sub algebra_as_string {
 		my $self	= shift;
 		state $S	= {
@@ -1482,8 +1495,6 @@ package Attean::Algebra::Update 0.012 {
 	}
 }
 
-# DELETE WHERE
-
 1;
 
 __END__