factor variable expansion out of assignment

diff --git a/lib/DX/State.pm b/lib/DX/State.pm
index 6f8a1f5..c430176 100644 (file)
--- a/lib/DX/State.pm
+++ b/lib/DX/State.pm
@@ -27,24 +27,33 @@ sub scope_var {
 }
 
 sub allocate_var {
-  my ($self, $name, $var) = @_;
-  my $id = join('_', $name, ++($self->id_gen->{$name}));
+  my ($self, $name, $var, $id_gen) = @_;
+  my $id = join('_', $name, ++($id_gen->{$name}||='000'));
   DX::Var->new(id => $id, %$var);
 }
 
-sub assign_vars {
+sub expand_vars {
   my ($self, %vars) = @_;
   my %by_id = %{$self->by_id};
-  my $state = $self->but(id_gen => { %{$self->id_gen} });
+  my %id_gen = %{$self->id_gen};
   foreach my $name (keys %vars) {
     unless (blessed($vars{$name})) {
-      my $var = $vars{$name} = $state->allocate_var($name, $vars{$name});
+      my $var = $vars{$name} = $self->allocate_var(
+        $name, $vars{$name}, \%id_gen
+      );
       $by_id{$var->id} = $var;
     }
   }
+  $self->but(
+    by_id => \%by_id, id_gen => \%id_gen,
+  ), %vars;
+}
+
+sub assign_vars {
+  my ($self, %vars) = @_;
+  my ($state, %expanded) = $self->expand_vars(%vars);
   $state->but(
-    by_id => \%by_id,
-    scope => { %{$self->scope}, map +($_ => $vars{$_}->id), keys %vars }
+    scope => { %{$self->scope}, map +($_ => $expanded{$_}->id), keys %expanded }
   );
 }