update generic interfaces to support co-variance and contra-variance.

@@ -68,7 +68,9 @@
   <ItemGroup>
     <None Include="config\AssemblyInfo.cs.template" />
     <None Include="local.properties.xml.template" />
-    <None Include="project.build" />
+    <None Include="project.build">
+      <SubType>Designer</SubType>
+    </None>
   </ItemGroup>
   <ItemGroup>
     <Content Include="local.properties.xml" />

@@ -1,7 +1,7 @@
-namespace gorilla.commons.utility
-{
-    public interface Builder<T>
-    {
-        T build();
-    }
+namespace gorilla.commons.utility
+{
+    public interface Builder<out T>
+    {
+        T build();
+    }
 }
\ No newline at end of file

@@ -1,10 +1,10 @@
-namespace gorilla.commons.utility
-{
-    public interface Callback : Command
-    {
-    }
-
-    public interface Callback<T> : ParameterizedCommand<T>
-    {
-    }
+namespace gorilla.commons.utility
+{
+    public interface Callback : Command
+    {
+    }
+
+    public interface Callback<in T> : ParameterizedCommand<T>
+    {
+    }
 }
\ No newline at end of file

@@ -1,6 +1,6 @@
-namespace gorilla.commons.utility
-{
-    public interface CallbackCommand<T> : ParameterizedCommand<Callback<T>>
-    {
-    }
+namespace gorilla.commons.utility
+{
+    public interface CallbackCommand<out T> : ParameterizedCommand<Callback<T>>
+    {
+    }
 }
\ No newline at end of file

@@ -1,19 +1,19 @@
-namespace gorilla.commons.utility
-{
-    public class ChainedMapper<Left, Middle, Right> : Mapper<Left, Right>
-    {
-        readonly Mapper<Left, Middle> left;
-        readonly Mapper<Middle, Right> right;
-
-        public ChainedMapper(Mapper<Left, Middle> left, Mapper<Middle, Right> right)
-        {
-            this.left = left;
-            this.right = right;
-        }
-
-        public Right map_from(Left item)
-        {
-            return right.map_from(left.map_from(item));
-        }
-    }
+namespace gorilla.commons.utility
+{
+    public class ChainedMapper<Left, Middle, Right> : Mapper<Left, Right>
+    {
+        readonly Mapper<Left, Middle> left;
+        readonly Mapper<Middle, Right> right;
+
+        public ChainedMapper(Mapper<Left, Middle> left, Mapper<Middle, Right> right)
+        {
+            this.left = left;
+            this.right = right;
+        }
+
+        public Right map_from(Left item)
+        {
+            return right.map_from(left.map_from(item));
+        }
+    }
 }
\ No newline at end of file

@@ -1,7 +1,7 @@
-namespace gorilla.commons.utility
-{
-    public interface Configuration<T>
-    {
-        void configure(T item);
-    }
+namespace gorilla.commons.utility
+{
+    public interface Configuration<in T>
+    {
+        void configure(T item);
+    }
 }
\ No newline at end of file

@@ -1,7 +1,7 @@
-namespace gorilla.commons.utility
-{
-    public interface Factory<T>
-    {
-        T create();
-    }
+namespace gorilla.commons.utility
+{
+    public interface Factory<out T>
+    {
+        T create();
+    }
 }
\ No newline at end of file

@@ -1,6 +1,6 @@
-namespace gorilla.commons.utility
-{
-    public delegate Out FactoryDelegate<In, Out>(In input);
-
-    public delegate Out FactoryDelegate<Out>();
+namespace gorilla.commons.utility
+{
+    public delegate Out FactoryDelegate<in In, out Out>(In input);
+
+    public delegate Out FactoryDelegate<out Out>();
 }
\ No newline at end of file

@@ -1,46 +1,46 @@
-using System;
-
-namespace gorilla.commons.utility
-{
-    [Serializable]
-    public class Id<T>
-    {
-        static public readonly Id<T> Default = new Id<T>(default(T));
-        readonly T id;
-
-        public Id(T id)
-        {
-            this.id = id;
-        }
-
-        static public implicit operator Id<T>(T id)
-        {
-            return new Id<T>(id);
-        }
-
-        static public implicit operator T(Id<T> id)
-        {
-            return id.id;
-        }
-
-        public bool Equals(Id<T> other)
-        {
-            if (ReferenceEquals(null, other)) return false;
-            if (ReferenceEquals(this, other)) return true;
-            return Equals(other.id, id);
-        }
-
-        public override bool Equals(object obj)
-        {
-            if (ReferenceEquals(null, obj)) return false;
-            if (ReferenceEquals(this, obj)) return true;
-            if (obj.GetType() != typeof (Id<T>)) return false;
-            return Equals((Id<T>) obj);
-        }
-
-        public override int GetHashCode()
-        {
-            return id.GetHashCode();
-        }
-    }
+using System;
+
+namespace gorilla.commons.utility
+{
+    [Serializable]
+    public class Id<T>
+    {
+        static public readonly Id<T> Default = new Id<T>(default(T));
+        readonly T id;
+
+        public Id(T id)
+        {
+            this.id = id;
+        }
+
+        static public implicit operator Id<T>(T id)
+        {
+            return new Id<T>(id);
+        }
+
+        static public implicit operator T(Id<T> id)
+        {
+            return id.id;
+        }
+
+        public bool Equals(Id<T> other)
+        {
+            if (ReferenceEquals(null, other)) return false;
+            if (ReferenceEquals(this, other)) return true;
+            return Equals(other.id, id);
+        }
+
+        public override bool Equals(object obj)
+        {
+            if (ReferenceEquals(null, obj)) return false;
+            if (ReferenceEquals(this, obj)) return true;
+            if (obj.GetType() != typeof (Id<T>)) return false;
+            return Equals((Id<T>) obj);
+        }
+
+        public override int GetHashCode()
+        {
+            return id.GetHashCode();
+        }
+    }
 }
\ No newline at end of file

@@ -1,7 +1,7 @@
-namespace gorilla.commons.utility
-{
-    public interface Import<T>
-    {
-        void import(T item);
-    }
+namespace gorilla.commons.utility
+{
+    public interface Import<in T>
+    {
+        void import(T item);
+    }
 }
\ No newline at end of file

@@ -1,7 +1,7 @@
-namespace gorilla.commons.utility
-{
-    public interface Mapper<Input, Output>
-    {
-        Output map_from(Input item);
-    }
+namespace gorilla.commons.utility
+{
+    public interface Mapper<in Input, out Output>
+    {
+        Output map_from(Input item);
+    }
 }
\ No newline at end of file

@@ -1,7 +1,7 @@
-namespace gorilla.commons.utility
-{
-    public interface ParameterizedCommand<T>
-    {
-        void run(T item);
-    }
+namespace gorilla.commons.utility
+{
+    public interface ParameterizedCommand<in T>
+    {
+        void run(T item);
+    }
 }
\ No newline at end of file

@@ -1,7 +1,7 @@
-namespace gorilla.commons.utility
-{
-    public interface Parser<T>
-    {
-        T parse();
-    }
+namespace gorilla.commons.utility
+{
+    public interface Parser<out T>
+    {
+        T parse();
+    }
 }
\ No newline at end of file

@@ -1,12 +1,12 @@
-namespace gorilla.commons.utility
-{
-    public interface Query<TOutput>
-    {
-        TOutput fetch();
-    }
-
-    public interface Query<TInput, TOutput>
-    {
-        TOutput fetch(TInput item);
-    }
+namespace gorilla.commons.utility
+{
+    public interface Query<out TOutput>
+    {
+        TOutput fetch();
+    }
+
+    public interface Query<in TInput, out TOutput>
+    {
+        TOutput fetch(TInput item);
+    }
 }
\ No newline at end of file

@@ -1,9 +1,9 @@
-using System.Collections.Generic;
-
-namespace gorilla.commons.utility
-{
-    public interface Registry<T> : IEnumerable<T>
-    {
-        IEnumerable<T> all();
-    }
+using System.Collections.Generic;
+
+namespace gorilla.commons.utility
+{
+    public interface Registry<out T> : IEnumerable<T>
+    {
+        IEnumerable<T> all();
+    }
 }
\ No newline at end of file

@@ -1,7 +1,7 @@
-namespace gorilla.commons.utility
-{
-    public interface Specification<T>
-    {
-        bool is_satisfied_by(T item);
-    }
+namespace gorilla.commons.utility
+{
+    public interface Specification<in T>
+    {
+        bool is_satisfied_by(T item);
+    }
 }
\ No newline at end of file

@@ -1,40 +1,41 @@
-using System;
-using System.Collections.Generic;
-
-namespace gorilla.commons.utility
-{
-    static public class SpecificationExtensions
-    {
-        static public IEnumerable<T> that_satisfy<T>(this IEnumerable<T> items_to_peek_in_to,
-                                                     Predicate<T> criteria_to_satisfy)
-        {
-            foreach (var item in items_to_peek_in_to ?? new List<T>())
-                if (item.satisfies(criteria_to_satisfy)) yield return item;
-        }
-
-        static public bool satisfies<T>(this T item_to_interrogate, Predicate<T> criteria_to_satisfy)
-        {
-            return criteria_to_satisfy(item_to_interrogate);
-        }
-
-        static public bool satisfies<T>(this T item_to_validate, Specification<T> criteria_to_satisfy)
-        {
-            return item_to_validate.satisfies(criteria_to_satisfy.is_satisfied_by);
-        }
-
-        static public Specification<T> and<T>(this Specification<T> left, Specification<T> right)
-        {
-            return new PredicateSpecification<T>(x => left.is_satisfied_by(x) && right.is_satisfied_by(x));
-        }
-
-        static public Specification<T> or<T>(this Specification<T> left, Specification<T> right)
-        {
-            return new PredicateSpecification<T>(x => left.is_satisfied_by(x) || right.is_satisfied_by(x));
-        }
-
-        static public Specification<T> not<T>(this Specification<T> original)
-        {
-            return new PredicateSpecification<T>(x => !original.is_satisfied_by(x));
-        }
-    }
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace gorilla.commons.utility
+{
+    static public class SpecificationExtensions
+    {
+        static public IEnumerable<T> that_satisfy<T>(this IEnumerable<T> items_to_peek_in_to,
+                                                     Predicate<T> criteria_to_satisfy)
+        {
+            foreach (var item in items_to_peek_in_to ?? Enumerable.Empty<T>())
+                if (item.satisfies(criteria_to_satisfy)) yield return item;
+        }
+
+        static public bool satisfies<T>(this T item_to_interrogate, Predicate<T> criteria_to_satisfy)
+        {
+            return criteria_to_satisfy(item_to_interrogate);
+        }
+
+        static public bool satisfies<T>(this T item_to_validate, Specification<T> criteria_to_satisfy)
+        {
+            return item_to_validate.satisfies(criteria_to_satisfy.is_satisfied_by);
+        }
+
+        static public Specification<T> and<T>(this Specification<T> left, Specification<T> right)
+        {
+            return new PredicateSpecification<T>(x => left.is_satisfied_by(x) && right.is_satisfied_by(x));
+        }
+
+        static public Specification<T> or<T>(this Specification<T> left, Specification<T> right)
+        {
+            return new PredicateSpecification<T>(x => left.is_satisfied_by(x) || right.is_satisfied_by(x));
+        }
+
+        static public Specification<T> not<T>(this Specification<T> original)
+        {
+            return new PredicateSpecification<T>(x => !original.is_satisfied_by(x));
+        }
+    }
 }
\ No newline at end of file

@@ -1,7 +1,7 @@
-namespace gorilla.commons.utility
-{
-    public interface SubjectOf<State> where State : utility.State
-    {
-        void change_state_to(State new_state);
-    }
+namespace gorilla.commons.utility
+{
+    public interface SubjectOf<in State> where State : utility.State
+    {
+        void change_state_to(State new_state);
+    }
 }
\ No newline at end of file

@@ -1,8 +1,8 @@
-namespace gorilla.commons.utility
-{
-    public interface ValueReturningVisitor<Value, T> : Visitor<T>
-    {
-        Value value { get; }
-        void reset();
-    }
+namespace gorilla.commons.utility
+{
+    public interface ValueReturningVisitor<out Value, in T> : Visitor<T>
+    {
+        Value value { get; }
+        void reset();
+    }
 }
\ No newline at end of file

@@ -1,7 +1,7 @@
-namespace gorilla.commons.utility
-{
-    public interface Visitable<T>
-    {
-        void accept(Visitor<T> visitor);
-    }
+namespace gorilla.commons.utility
+{
+    public interface Visitable<out T>
+    {
+        void accept(Visitor<T> visitor);
+    }
 }
\ No newline at end of file

@@ -1,7 +1,7 @@
-namespace gorilla.commons.utility
-{
-    public interface Visitor<T>
-    {
-        void visit(T item_to_visit);
-    }
+namespace gorilla.commons.utility
+{
+    public interface Visitor<in T>
+    {
+        void visit(T item_to_visit);
+    }
 }
\ No newline at end of file

Commit 0d58668

Commit `0d58668`