Marking endpoints and specs thereof

lib/treetop/runtime/interval_skip_list.rb

@@ -27,6 +27,7 @@ def containing(n)
   def insert(range, marker)
     first_node = insert_node(range.first)
     last_node = insert_node(range.last)
+    last_node.endpoint_of.push(marker)
 
     cur_node = first_node
     cur_level = first_node.height - 1
@@ -131,12 +132,13 @@ def initialize(height)
   end
 
   class Node < HeadNode
-    attr_reader :key, :markers
+    attr_reader :key, :markers, :endpoint_of
 
     def initialize(key, height, path)
       super(height)
       @key = key
       @markers = []
+      @endpoint_of = []
 
       update_forward_pointers(path)
       promote_markers(path)

spec/runtime/interval_skip_list_spec.rb

@@ -89,6 +89,10 @@ def confirm_containing_intervals(range, *markers)
       it "has no markers" do
         node.markers.should be_empty
       end
+
+      it "is not an endpoint of any interval" do
+        node.endpoint_of.should be_empty
+      end
     end
 
     describe " #nodes[1]" do
@@ -110,6 +114,10 @@ def confirm_containing_intervals(range, *markers)
       it "has :a as its only marker" do
         node.markers.should have_marker(:a)
       end
+
+      it "is an endpoint of only :a" do
+        node.endpoint_of.should have_marker(:a)
+      end
     end
 
     describe ", and then :b is inserted on 1..5" do
@@ -154,6 +162,10 @@ def confirm_containing_intervals(range, *markers)
         it "has no markers" do
           node.markers.should be_empty
         end
+
+        it "is not an endpoint of any interval" do
+          node.endpoint_of.should be_empty
+        end
       end
 
       describe " #nodes[1]" do
@@ -177,6 +189,10 @@ def confirm_containing_intervals(range, *markers)
         it "has :a and :b as its only markers" do
           node.markers.should have_markers(:a, :b)
         end
+
+        it "is an endpoint of only :b" do
+          node.endpoint_of.should have_marker(:b)
+        end
       end
 
       describe " #nodes[2]" do
@@ -198,6 +214,10 @@ def confirm_containing_intervals(range, *markers)
         it "has :a its only marker" do
           node.markers.should have_marker(:a)
         end
+
+        it "is an endpoint of only :a" do
+          node.endpoint_of.should have_marker(:a)
+        end
       end
 
       describe ", and then :c is inserted on 1..3" do
@@ -226,6 +246,10 @@ def confirm_containing_intervals(range, *markers)
           it "has no markers" do
             node.markers.should be_empty
           end
+
+          it "is not an endpoint of any interval" do
+            node.endpoint_of.should be_empty
+          end
         end
 
         describe " #nodes[1]" do
@@ -253,6 +277,10 @@ def confirm_containing_intervals(range, *markers)
           it "has :a, :b, and :c as its only markers" do
             node.markers.should have_markers(:a, :b, :c)
           end
+
+          it "is an endpoint of only :c" do
+            node.endpoint_of.should have_marker(:c)
+          end
         end
 
         describe " #nodes[2]" do
@@ -273,6 +301,10 @@ def confirm_containing_intervals(range, *markers)
           it "has :b as its only markers" do
             node.markers.should have_marker(:b)
           end
+
+          it "is an endpoint of only :b" do
+            node.endpoint_of.should have_marker(:b)
+          end
         end
 
         describe " #nodes[3]" do
@@ -294,6 +326,10 @@ def confirm_containing_intervals(range, *markers)
           it "has :a as its only marker" do
             node.markers.should have_marker(:a)
           end
+
+          it "is an endpoint of only :a" do
+            node.endpoint_of.should have_marker(:a)
+          end
         end
 
         describe ", and then :d is inserted on 1..9" do
@@ -322,6 +358,10 @@ def confirm_containing_intervals(range, *markers)
             it "has no markers" do
               node.markers.should be_empty
             end
+
+            it "is not an endpoint of any interval" do
+              node.endpoint_of.should be_empty
+            end
           end
 
           describe " #nodes[1]" do
@@ -349,6 +389,10 @@ def confirm_containing_intervals(range, *markers)
             it "has :a, :b, :c, :d as its only markers" do
               node.markers.should have_markers(:a, :b, :c, :d)
             end
+
+            it "is an endpoint of only :c" do
+              node.endpoint_of.should have_marker(:c)
+            end
           end
 
           describe " #nodes[2]" do
@@ -369,6 +413,10 @@ def confirm_containing_intervals(range, *markers)
             it "has :b as its only marker" do
               node.markers.should have_marker(:b)
             end
+
+            it "is an endpoint of only :b" do
+              node.endpoint_of.should have_marker(:b)
+            end      
           end
 
           describe " #nodes[3]" do
@@ -393,6 +441,10 @@ def confirm_containing_intervals(range, *markers)
             it "has :a, :d as its only markers" do
               node.markers.should have_markers(:a, :d)
             end
+
+            it "is an endpoint of only :a" do
+              node.endpoint_of.should have_marker(:a)
+            end
           end
 
           describe " #nodes[4]" do
@@ -412,6 +464,10 @@ def confirm_containing_intervals(range, *markers)
             it "has :d as its only marker" do
               node.markers.should have_marker(:d)
             end
+
+            it "is an endpoint of only :d" do
+              node.endpoint_of.should have_marker(:d)
+            end
           end
         end
       end