tests: add some runtime error in nitin.input

[nit.git] / lib / a_star.nit

diff --git a/lib/a_star.nit b/lib/a_star.nit
index 9780e12..cc0cba3 100644 (file)
--- a/lib/a_star.nit
+++ b/lib/a_star.nit
@@ -14,9 +14,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Services related to pathfinding of graphs using A*
-# A single graph may have different properties according to the `PathContext` used
+# A* pathfinding in graphs
 #
+# A single graph may have different properties according to the `PathContext` used
 #
 # Usage:
 #
@@ -188,13 +188,21 @@ class Node
                end
        end
 
+       # Find the closest node accepted by `cond` under `max_cost`
+       fun find_closest(max_cost: Int, context: PathContext, cond: nullable TargetCondition[N]): nullable N
+       do
+               var path = path_to_alts(null, max_cost, context, cond)
+               if path == null then return null
+               return path.nodes.last
+       end
+
        # We customize the serialization process to avoid problems with recursive
        # serialization engines. These engines, such as `JsonSerializer`,
        # are at danger to serialize the graph as a very deep tree.
        # With a large graph it can cause a stack overflow.
        #
        # Instead, we serialize the nodes first and then the links.
-       redef fun core_serialize_to(serializer: Serializer)
+       redef fun core_serialize_to(serializer)
        do
                serializer.serialize_attribute("graph", graph)
        end
@@ -265,7 +273,7 @@ class Graph[N: Node, L: Link]
        # Used to check if nodes have been searched in one pathfinding
        private var pathfinding_current_evocation: Int = 0
 
-       redef fun core_serialize_to(serializer: Serializer)
+       redef fun core_serialize_to(serializer)
        do
                serializer.serialize_attribute("nodes", nodes)
                serializer.serialize_attribute("links", links)
@@ -316,7 +324,7 @@ class AStarPath[N]
 end
 
 # Context related to an evocation of pathfinding
-class PathContext
+abstract class PathContext
        serialize
 
        # Type of the nodes in `graph`
@@ -380,7 +388,7 @@ class WeightedPathContext
                self.worst_cost = worst_cost
        end
 
-       redef var worst_cost: Int is noinit
+       redef var worst_cost is noinit
 
        redef fun cost(l) do
                return l.weight
@@ -400,7 +408,7 @@ class WeightedLink
 end
 
 # Advanced path conditions with customizable accept states
-class TargetCondition[N: Node]
+abstract class TargetCondition[N: Node]
        serialize
 
        # Should the pathfinding accept `node` as a goal?