* lib/tsort.rb (TSort.tsort): Extracted from TSort#tsort.

(TSort.tsort_each): Extracted from TSort#tsort_each.
  (TSort.strongly_connected_components): Extracted from
  TSort#strongly_connected_components.
  (TSort.each_strongly_connected_component): Extracted from
  TSort#each_strongly_connected_component.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@43342 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,12 @@
+Fri Oct 18 00:57:07 2013  Tanaka Akira  <akr@fsij.org>
+
+	* lib/tsort.rb (TSort.tsort): Extracted from TSort#tsort.
+	  (TSort.tsort_each): Extracted from TSort#tsort_each.
+	  (TSort.strongly_connected_components): Extracted from
+	  TSort#strongly_connected_components.
+	  (TSort.each_strongly_connected_component): Extracted from
+	  TSort#each_strongly_connected_component.
+
 Thu Oct 17 18:50:08 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* gc.c (CALC_EXACT_MALLOC_SIZE_CHECK_OLD_SIZE): introduced.

NEWS

@@ -246,6 +246,10 @@ with all sufficient information, see the ChangeLog file.
 
 * TSort
   * New methods:
+    * TSort.tsort
+    * TSort.tsort_each
+    * TSort.strongly_connected_components
+    * TSort.each_strongly_connected_component
     * TSort.each_strongly_connected_component_from
 
 * WEBrick

lib/tsort.rb

@@ -145,8 +145,34 @@ module TSort
   #   p graph.tsort # raises TSort::Cyclic
   #
   def tsort
+    each_node = method(:tsort_each_node)
+    each_child = method(:tsort_each_child)
+    TSort.tsort(each_node, each_child)
+  end
+
+  # Returns a topologically sorted array of nodes.
+  # The array is sorted from children to parents, i.e.
+  # the first element has no child and the last node has no parent.
+  #
+  # The graph is represented by _each_node_ and _each_child_.
+  # _each_node_ should have +call+ method which yields for each node in the graph.
+  # _each_child_ should have +call+ method which takes a node argument and yields for each child node.
+  #
+  # If there is a cycle, TSort::Cyclic is raised.
+  #
+  #   g = {1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]}
+  #   each_node = lambda {|&b| g.each_key(&b) }
+  #   each_child = lambda {|n, &b| g[n].each(&b) }
+  #   p TSort.tsort(each_node, each_child) #=> [4, 2, 3, 1]
+  #
+  #   g = {1=>[2], 2=>[3, 4], 3=>[2], 4=>[]}
+  #   each_node = lambda {|&b| g.each_key(&b) }
+  #   each_child = lambda {|n, &b| g[n].each(&b) }
+  #   p TSort.tsort(each_node, each_child) # raises TSort::Cyclic
+  #
+  def TSort.tsort(each_node, each_child)
     result = []
-    tsort_each {|element| result << element}
+    TSort.tsort_each(each_node, each_child) {|element| result << element}
     result
   end
 
@@ -173,8 +199,29 @@ module TSort
   #   #   3
   #   #   1
   #
-  def tsort_each # :yields: node
-    each_strongly_connected_component {|component|
+  def tsort_each(&block) # :yields: node
+    each_node = method(:tsort_each_node)
+    each_child = method(:tsort_each_child)
+    TSort.tsort_each(each_node, each_child, &block)
+  end
+
+  # The iterator version of the TSort.tsort method.
+  #
+  # The graph is represented by _each_node_ and _each_child_.
+  # _each_node_ should have +call+ method which yields for each node in the graph.
+  # _each_child_ should have +call+ method which takes a node argument and yields for each child node.
+  #
+  #   g = {1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]}
+  #   each_node = lambda {|&b| g.each_key(&b) }
+  #   each_child = lambda {|n, &b| g[n].each(&b) }
+  #   TSort.tsort_each(each_node, each_child) {|n| p n }
+  #   #=> 4
+  #   #   2
+  #   #   3
+  #   #   1
+  #
+  def TSort.tsort_each(each_node, each_child) # :yields: node
+    TSort.each_strongly_connected_component(each_node, each_child) {|component|
       if component.size == 1
         yield component.first
       else
@@ -203,8 +250,34 @@ module TSort
   #   p graph.strongly_connected_components #=> [[4], [2, 3], [1]]
   #
   def strongly_connected_components
+    each_node = method(:tsort_each_node)
+    each_child = method(:tsort_each_child)
+    TSort.strongly_connected_components(each_node, each_child)
+  end
+
+  # Returns strongly connected components as an array of arrays of nodes.
+  # The array is sorted from children to parents.
+  # Each elements of the array represents a strongly connected component.
+  #
+  # The graph is represented by _each_node_ and _each_child_.
+  # _each_node_ should have +call+ method which yields for each node in the graph.
+  # _each_child_ should have +call+ method which takes a node argument and yields for each child node.
+  #
+  #   g = {1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]}
+  #   each_node = lambda {|&b| g.each_key(&b) }
+  #   each_child = lambda {|n, &b| g[n].each(&b) }
+  #   p TSort.strongly_connected_components(each_node, each_child)
+  #   #=> [[4], [2], [3], [1]]
+  #
+  #   g = {1=>[2], 2=>[3, 4], 3=>[2], 4=>[]}
+  #   each_node = lambda {|&b| g.each_key(&b) }
+  #   each_child = lambda {|n, &b| g[n].each(&b) }
+  #   p TSort.strongly_connected_components(each_node, each_child)
+  #   #=> [[4], [2, 3], [1]]
+  #
+  def TSort.strongly_connected_components(each_node, each_child)
     result = []
-    each_strongly_connected_component {|component| result << component}
+    TSort.each_strongly_connected_component(each_node, each_child) {|component| result << component}
     result
   end
 
@@ -237,12 +310,41 @@ module TSort
   #   #   [2, 3]
   #   #   [1]
   #
-  def each_strongly_connected_component # :yields: nodes
+  def each_strongly_connected_component(&block) # :yields: nodes
+    each_node = method(:tsort_each_node)
+    each_child = method(:tsort_each_child)
+    TSort.each_strongly_connected_component(each_node, each_child, &block)
+  end
+
+  # The iterator version of the TSort.strongly_connected_components method.
+  #
+  # The graph is represented by _each_node_ and _each_child_.
+  # _each_node_ should have +call+ method which yields for each node in the graph.
+  # _each_child_ should have +call+ method which takes a node argument and yields for each child node.
+  #
+  #   g = {1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]}
+  #   each_node = lambda {|&b| g.each_key(&b) }
+  #   each_child = lambda {|n, &b| g[n].each(&b) }
+  #   TSort.each_strongly_connected_component(each_node, each_child) {|scc| p scc }
+  #   #=> [4]
+  #   #   [2]
+  #   #   [3]
+  #   #   [1]
+  #
+  #   g = {1=>[2], 2=>[3, 4], 3=>[2], 4=>[]}
+  #   each_node = lambda {|&b| g.each_key(&b) }
+  #   each_child = lambda {|n, &b| g[n].each(&b) }
+  #   TSort.each_strongly_connected_component(each_node, each_child) {|scc| p scc }
+  #   #=> [4]
+  #   #   [2, 3]
+  #   #   [1]
+  #
+  def TSort.each_strongly_connected_component(each_node, each_child) # :yields: nodes
     id_map = {}
     stack = []
-    tsort_each_node {|node|
+    each_node.call {|node|
       unless id_map.include? node
-        each_strongly_connected_component_from(node, id_map, stack) {|c|
+        TSort.each_strongly_connected_component_from(node, each_child, id_map, stack) {|c|
           yield c
         }
       end
@@ -285,7 +387,7 @@ module TSort
   #
   # _node_ is the first node.
   # _each_child_ should have +call+ method which takes a node argument
-  # and yields for each adjacent node.
+  # and yields for each child node.
   #
   # Return value is unspecified.
   #

test/test_tsort.rb

@@ -41,7 +41,53 @@ class TSortTest < Test::Unit::TestCase # :nodoc:
       a.strongly_connected_components.map {|nodes| nodes.sort})
   end
 
-  def test_noclass
+  def test_s_tsort
+    g = {1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]}
+    each_node = lambda {|&b| g.each_key(&b) }
+    each_child = lambda {|n, &b| g[n].each(&b) }
+    assert_equal([4, 2, 3, 1], TSort.tsort(each_node, each_child))
+    g = {1=>[2], 2=>[3, 4], 3=>[2], 4=>[]}
+    assert_raise(TSort::Cyclic) { TSort.tsort(each_node, each_child) }
+  end
+
+  def test_s_tsort_each
+    g = {1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]}
+    each_node = lambda {|&b| g.each_key(&b) }
+    each_child = lambda {|n, &b| g[n].each(&b) }
+    r = []
+    TSort.tsort_each(each_node, each_child) {|n| r << n }
+    assert_equal([4, 2, 3, 1], r)
+  end
+
+  def test_s_strongly_connected_components
+    g = {1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]}
+    each_node = lambda {|&b| g.each_key(&b) }
+    each_child = lambda {|n, &b| g[n].each(&b) }
+    assert_equal([[4], [2], [3], [1]],
+                 TSort.strongly_connected_components(each_node, each_child))
+    g = {1=>[2], 2=>[3, 4], 3=>[2], 4=>[]}
+    assert_equal([[4], [2, 3], [1]],
+                 TSort.strongly_connected_components(each_node, each_child))
+  end
+
+  def test_s_each_strongly_connected_component
+    g = {1=>[2, 3], 2=>[4], 3=>[2, 4], 4=>[]}
+    each_node = lambda {|&b| g.each_key(&b) }
+    each_child = lambda {|n, &b| g[n].each(&b) }
+    r = []
+    TSort.each_strongly_connected_component(each_node, each_child) {|scc|
+      r << scc
+    }
+    assert_equal([[4], [2], [3], [1]], r)
+    g = {1=>[2], 2=>[3, 4], 3=>[2], 4=>[]}
+    r = []
+    TSort.each_strongly_connected_component(each_node, each_child) {|scc|
+      r << scc
+    }
+    assert_equal([[4], [2, 3], [1]], r)
+  end
+
+  def test_s_each_strongly_connected_component_from
     g = {1=>[2], 2=>[3, 4], 3=>[2], 4=>[]}
     each_child = lambda {|n, &b| g[n].each(&b) }
     r = []