From: Matt S Trout <mst@shadowcat.co.uk>
Date: Mon, 3 Feb 2014 11:23:22 +0000 (+0000)
Subject: introduce root set
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=scpubgit%2FDKit.git;a=commitdiff_plain;h=d95799c4cfce222bcb8bffd07dd88a5d2d1e69ab

introduce root set
---

diff --git a/lib/DX/Op/MemberOf.pm b/lib/DX/Op/MemberOf.pm
index 3bcca39..776ecf9 100644
--- a/lib/DX/Op/MemberOf.pm
+++ b/lib/DX/Op/MemberOf.pm
@@ -17,8 +17,7 @@ sub run {
   my ($member, $of) = @args{qw(member of)};
   die "member bound" if $member->is_bound;
   my $set = $state->facts->{$of->bound_value};
-  my $stream = $set->to_stream;
-  return $state->bind_stream_then($member, $stream, $self->next);
+  return $state->bind_root_set_then($member, $set, $self->next);
 }
 
 1;
diff --git a/lib/DX/State.pm b/lib/DX/State.pm
index 9f4bf6b..106bbfc 100644
--- a/lib/DX/State.pm
+++ b/lib/DX/State.pm
@@ -74,6 +74,15 @@ sub bind_stream_then {
   )->mark_choice($bound);
 }
 
+sub bind_root_set_then {
+  my ($self, $var, $set, $then) = @_;
+  my $bound = $var->with_root_set($set);
+  $self->but(
+    by_id => { %{$self->by_id}, $var->id => $bound },
+    next_op => $then
+  )->mark_choice($bound);
+}
+
 sub mark_choice {
   my ($self, $var) = @_;
   $self->but(last_choice => [ $self, $var ]);
diff --git a/lib/DX/Var.pm b/lib/DX/Var.pm
index d17f375..2a1f83c 100644
--- a/lib/DX/Var.pm
+++ b/lib/DX/Var.pm
@@ -4,7 +4,15 @@ use Moo;
 
 has id => (is => 'ro', required => 1);
 
-has bound_stream => (is => 'ro');
+has root_set => (is => 'ro', predicate => 1);
+
+has bound_stream => (
+  is => 'lazy', predicate => 1, clearer => 1,
+  builder => sub {
+    my ($self) = @_;
+    $self->root_set->to_stream;
+  }
+);
 
 has bound_value => (is => 'lazy', predicate => 1, clearer => 1, builder => sub {
   if (defined(my $next = $_[0]->bound_stream->next)) {
@@ -18,7 +26,7 @@ has action => (is => 'ro');
 
 sub is_bound {
   my ($self) = @_;
-  $self->has_bound_value || $self->bound_stream;
+  $self->has_bound_value || $self->has_bound_stream || $self->has_root_set;
 }
 
 sub with_stream {
@@ -36,6 +44,11 @@ sub with_action {
   $self->new(%$self, action => $action);
 }
 
+sub with_root_set {
+  my ($self, $set) = @_;
+  $self->new(%$self, root_set => $set);
+}
+
 sub copy {
   my ($self) = @_;
   ref($self)->new(%$self);