From: Jean Privat <jean@pryen.org>
Date: Sat, 11 Apr 2015 17:11:40 +0000 (+0700)
Subject: lib/a_star: avoid bad autocast
X-Git-Tag: v0.7.4~26^2~4
X-Git-Url: http://nitlanguage.org

lib/a_star: avoid bad autocast

Seriously, this one case might be a strong argument against autocasts

~~~
frontier_node = frontier_node.best_source.as(not null)
~~~

is auto-casted as

~~~
frontier_node = frontier_node.best_source.as(not null).as(N)
~~~

bun since the N is `nullable Node`, the not-null information was lost in the
cast.

Signed-off-by: Jean Privat <jean@pryen.org>
---

diff --git a/lib/a_star.nit b/lib/a_star.nit
index 2cbd7cf..9735d90 100644
--- a/lib/a_star.nit
+++ b/lib/a_star.nit
@@ -147,7 +147,8 @@ class Node
 
 				while frontier_node != self do
 					path.nodes.unshift(frontier_node)
-					frontier_node = frontier_node.best_source.as(not null)
+					frontier_node = frontier_node.best_source
+					assert frontier_node != null
 				end
 
 				return path