Add vectors, neighbor and incident lookups

lib/steffi/edge_set.rb

@@ -26,7 +26,7 @@ def [] n
     end
 
     def each
-      0.upto size do |i|
+      0.upto size - 1 do |i|
         yield self[i]
       end
     end
@@ -35,5 +35,19 @@ def find pair, error=false
       id = FFI::MemoryPointer.new :int
       Igraph.get_eid @graph.pointer, id, pair.first, pair.last, @graph.directed?, error
     end
+
+    # def find_pairs *pairs
+    #   edges = Vector.new
+    #   error = false
+    #   Igraph.get_eids @graph.pointer, edges.pointer, Vector.from_a(pairs), nil, @graph.directed?, error
+    #   edges
+    # end
+
+    # def find_path *vertices
+    #   edges = Vector.new
+    #   error = false
+    #   Igraph.get_eids @graph.pointer, edges.pointer, nil, Vector.from_a(pairs), nil, @graph.directed?, error
+    #   edges
+    # end
   end
 end

lib/steffi/ffi.rb

@@ -34,13 +34,13 @@ def self.method_missing name, *args, &block
       end
     end
 
-    # 2.1 Graph constructors and deconstructors
+    # 4.2.1 Graph constructors and deconstructors
     bind :empty,       [:pointer, :int, :bool]
     bind :empty_attrs, [:pointer, :int, :bool, :pointer] # graph, vertex count, directed?, (void *) attributes
     bind :copy,        [:pointer, :pointer]
     bind :destroy,     [:pointer]
 
-    # 2.2 Basic query operations
+    # 4.2.2 Basic query operations
     bind :vcount,  [:pointer], :int
     bind :ecount,  [:pointer], :int
     bind :edge,    [:pointer, :int, :pointer, :pointer]
@@ -52,21 +52,65 @@ def self.method_missing name, *args, &block
     # graph, &[edge #]. &[pairs], &[path], directed?, error?
     bind :get_eids_multi, [:pointer, :pointer, :pointer, :pointer, :bool, :bool]
 
-    bind :neighbors,   [:pointer, :pointer, :int, :int] # graph, &[result], node, mode
-    bind :incident,    [:pointer, :pointer, :int, :int] # graph, &[result], node, mode
+    bind :neighbors,   [:pointer, :pointer, :int, :int]
+    bind :incident,    [:pointer, :pointer, :int, :int] 
     bind :is_directed, [:pointer], :bool
 
     # graph, &[results], vids, mode, loops?
     bind :degree, [:pointer, :pointer, :int, :bool]
 
-    # 2.3 Adding and deleting vertices and edges
+    # 4.2.3 Adding and deleting vertices and edges
     bind :add_edge,        [:pointer, :int, :int]
     bind :add_edges,       [:pointer, :pointer, :pointer] # graph, [edges], (void *) attrs
     bind :add_vertices,    [:pointer, :int, :pointer]     # graph, id, (void *) attr
     bind :delete_edges,    [:pointer, :pointer]           # graph, eids
     bind :delete_vertices, [:pointer, :pointer]           # graph, vids
 
-    # 2.4 Deprecated
-    # igraph_adjacent
+    # 7.2.2
+    bind :vector_init,      [:pointer, :long]            # vector, size
+    bind :vector_init_copy, [:pointer, :pointer, :long]  # vector, data, length
+    bind :vector_init_seq,  [:pointer, :double, :double] # vector, from, to
+    bind :vector_copy,      [:pointer, :pointer]         # from, to
+    bind :vector_destroy,   [:pointer]                   # vector
+
+    # 7.2.3 Initializing elements
+    bind :vector_null, [:pointer],          :void # vector
+    bind :vector_fill, [:pointer, :double], :void # vector, value
+
+    # 7.2.4 Accessing elements
+    bind :vector_e,     [:pointer, :long], :double        # vector, pos => value
+    bind :vector_e_ptr, [:pointer, :long], :pointer       # vector, pos => address
+    bind :vector_set,   [:pointer, :long, :double], :void # vector, pos, value
+    bind :vector_tail,  [:pointer], :double               # vector => value
+
+    # 7.2.5 Vector views
+    bind :vector_view, [:pointer, :pointer, :long], :pointer # vector, data, len => vector
+
+    # 7.2.6 Copying vectors
+    bind :vector_copy_to, [:pointer, :pointer], :void # vector, array
+    bind :vector_update,  [:pointer, :pointer]        # to, from
+    bind :vector_append,  [:pointer, :pointer]        # to, from
+    bind :vector_swap,    [:pointer, :pointer]        # v1, v2
+
+    # 7.2.7 Exchanging elements
+    # ...
+    # 7.2.8 Vector operations
+    # ...
+    # 7.2.9 Vector comparisons
+    # ...
+    # 7.2.10 Finding minimum and maximum
+    # ...
+    # 7.2.11 Vector properties
+    # ...
+    # 7.2.12 Searching for elements
+    # ...
+    # 7.2.13 Resizing operations
+    # ...
+    # 7.2.14 Sorting
+    # ...
+    # 7.2.15 Set operations on sorted vectors
+    # ...
+    # 7.2.16 Pointer vectors
+    # ...
   end
 end

lib/steffi/vector.rb

@@ -1,16 +1,10 @@
 module Steffi
-
   module Igraph
-    bind :vector_init, [:pointer, :long], :int
-    bind :vector_e, [:pointer, :long], :double
-    bind :vector_set, [:pointer, :long, :double], :void
-    bind :vector_size, [:pointer], :long
-    bind :vector_push_back, [:pointer, :double], :int
-    bind :vector_destroy, [:pointer], :void
+    bind :vector_push_back, [:pointer, :double]
+    bind :vector_size,      [:pointer], :int
   end
 
   class Vector
-
     class Struct < FFI::ManagedStruct
       layout :stor_begin, :pointer,
              :stor_end,   :pointer,
@@ -21,45 +15,56 @@ def self.release ptr
       end
     end
 
+    def self.null
+      new { |v| Igraph.vector_init v.pointer, 0 }
+    end
+
+    def self.from_a ary
+      v = new  { |v| Igraph.vector_init v.pointer, 0 }
+      ary.each { |i| v << i}
+      v
+    end
+
     include Enumerable
 
-    attr_reader :ptr
+    attr_reader :pointer
 
     def initialize
-      @ptr = FFI::MemoryPointer.new Vector::Struct
-      Igraph.vector_init ptr, 0
+      @pointer = FFI::MemoryPointer.new Vector::Struct
+      yield self if block_given?
+      self
     end
 
-    def << obj
-      Igraph.vector_push_back ptr, obj.to_f
+    def length
+      Igraph.vector_size @pointer
     end
 
-    def [] i
-      Igraph.vector_e ptr, i
+    def << obj
+      Igraph.vector_push_back @pointer, obj.to_f
     end
 
-    def []= i, obj
-      Igraph.vector_set ptr, i, obj.to_f
+    def [] i
+      Igraph.vector_e @pointer, i
     end
 
-    def size
-      Igraph.vector_size ptr
-    end
+    # def []= i, obj
+    #   Igraph.vector_set ptr, i, obj.to_f
+    # end
 
     def each
-      0.upto(size-1) { |i| yield self[i] }
-    end
-
-    def to_s
-      to_a.to_s
+      0.upto length - 1 do |i| 
+        yield self[i]
+      end
     end
 
-    def self.from_a ary
-      v = new
-      ary.each { |i| v << i }
-      v
-    end
+    # def to_s
+    #   to_a.to_s
+    # end
 
+    # def self.from_a ary
+    #   v = new
+    #   ary.each { |i| v << i }
+    #   v
+    # end
   end
-
 end

lib/steffi/vertex.rb

@@ -1,7 +1,21 @@
 module Steffi
   class Vertex
-    def initialize graph
-      @graph = graph
+    def initialize graph, id
+      @graph, @id = graph, id
+    end
+
+    def neighbors
+      mode = 3 # IGRAPH_ALL / FIXME: define and use enum
+      v = Vector.null
+      Igraph.neighbors @graph.pointer, v.pointer, @id, mode
+      v.to_a
+    end
+
+    def incident
+      mode = 3 # IGRAPH_ALL / FIXME: define and use enum
+      v = Vector.null
+      Igraph.incident @graph.pointer, v.pointer, @id, mode
+      v.map &:to_i
     end
   end
 end

lib/steffi/vertex_set.rb

@@ -1,5 +1,7 @@
 module Steffi
   class VertexSet
+    include Enumerable
+
     def initialize graph
       @graph = graph
     end
@@ -11,5 +13,15 @@ def size
     def empty?
       size == 0
     end
+
+    def [] n
+      Vertex.new @graph, n
+    end
+
+    def each
+      0.upto size - 1 do |i|
+        yield self[i]
+      end
+    end
   end
 end

spec/steffi/graph_spec.rb

@@ -15,7 +15,7 @@
   #   expect { Steffi::Graph.famous 'non-existent' }.to raise_error(Steffi::Igraph::Error)
   # end
 
-  # -- 2 -----
+  # -- 4.1-3 -----
 
   it 'can create empty graphs' do
     g = Steffi::Graph.empty 5
@@ -60,5 +60,25 @@
   end
 
   pending 'can lookup directed edges'
-  pending 'can handle errors when looking up edges'
+  pending 'can handle errors when looking up edges (eid, eids, eids_multi)'
+
+  # it 'can look up a list of edges by vertex' do
+  #   g = Steffi::Graph.full 3
+  #   g.edges.find_pairs([0,1], [1,2]).should == [0, 1]
+  # end
+
+  # it 'can look up a list of edges in a path' do
+  #   g = Steffi::Graph.full 3
+  #   g.edges.find_path([0,1,2]).should == [0, 1]
+  # end
+
+  it 'can look up neighbors' do
+    g = Steffi::Graph.full 5
+    g.vertices.first.neighbors.should == [1, 2, 3, 4]
+  end
+
+  it 'knows incident edges' do
+    g = Steffi::Graph.full 3
+    g.vertices.first.incident.should == [0, 1]
+  end
 end

spec/steffi/vector_spec.rb

@@ -1,6 +1,11 @@
 require 'helper'
 
 describe Steffi::Vector do
+  it 'can be copied from an array' do
+    v = Steffi::Vector.from_a [0, 1, 2]
+    v.length.should == 3
+  end
+
   # subject do 
   #   v = Steffi::Vector.new
   #   v << 3.1415