parser: `Visitor::visit` does not accepts `null`

[nit.git] / src / poset.nit

diff --git a/src/poset.nit b/src/poset.nit
index b6346c7..0a4a4b9 100644 (file)
--- a/src/poset.nit
+++ b/src/poset.nit
@@ -26,13 +26,12 @@ class POSet[E: Object]
        super NaiveCollection[E]
        super AbstractSorter[E]
 
-       redef fun iterator do return nodes.iterator
+       redef fun iterator do return elements.keys.iterator
 
        # All the nodes
-       private var nodes: Set[E] = new HashSet[E]
        private var elements: HashMap[E, POSetElement[E]] = new HashMap[E, POSetElement[E]]
 
-       redef fun has(e) do return self.nodes.has(e)
+       redef fun has(e) do return self.elements.keys.has(e)
 
        # Add a node (an element) to the posed
        # The new element is added unconnected to any other nodes (it is both a new root and a new leaf).
@@ -40,9 +39,8 @@ class POSet[E: Object]
        # If `e' is already present in the POSet then just return the POSetElement (usually you will prefer []) is this case.
        fun add_node(e: E): POSetElement[E]
        do
-               if nodes.has(e) then return self.elements[e]
-               nodes.add(e)
-               var poe = new POSetElement[E](self, e, nodes.length)
+               if elements.keys.has(e) then return self.elements[e]
+               var poe = new POSetElement[E](self, e, elements.length)
                poe.tos.add(e)
                poe.froms.add(e)
                self.elements[e] = poe
@@ -62,7 +60,7 @@ class POSet[E: Object]
        # REQUIRE: has(e)
        fun [](e: E): POSetElement[E]
        do
-               assert nodes.has(e)
+               assert elements.keys.has(e)
                return self.elements[e]
        end
 
@@ -112,7 +110,7 @@ class POSet[E: Object]
        # Since the POSet is reflexive, true is returned if `f == t'.
        fun has_edge(f,t: E): Bool
        do
-               if not nodes.has(f) then return false
+               if not elements.keys.has(f) then return false
                var fe = self.elements[f]
                return fe.tos.has(t)
        end
@@ -121,7 +119,7 @@ class POSet[E: Object]
        # Note that because of loops, the result may not be the expected one.
        fun has_direct_edge(f,t: E): Bool
        do
-               if not nodes.has(f) then return false
+               if not elements.keys.has(f) then return false
                var fe = self.elements[f]
                return fe.dtos.has(t)
        end
@@ -134,7 +132,8 @@ class POSet[E: Object]
                var f = new OProcess("dot", "-Txlib")
                #var f = stdout
                f.write "digraph \{\n"
-               for x in nodes do
+               for x in elements.keys do
+                       f.write "\"{x}\";\n"
                        var xe = self.elements[x]
                        for y in xe.dtos do
                                if self.has_edge(y,x) then