1 files changed, 44 insertions, 0 deletions
diff --git a/slips/src/app/Marina/Infrastructure/SpecificationBuilder.cs b/slips/src/app/Marina/Infrastructure/SpecificationBuilder.cs
new file mode 100644
index 0000000..1651733
--- /dev/null
+++ b/slips/src/app/Marina/Infrastructure/SpecificationBuilder.cs
@@ -0,0 +1,44 @@
+namespace Marina.Infrastructure {
+	public class SpecificationBuilder< T > : ISpecificationBuilder< T > {
+		public SpecificationBuilder() : this( new BlankSpecification( ) ) {}
+
+		public SpecificationBuilder( ISpecification< T > criteria ) {
+			_criteria = criteria;
+		}
+
+		public bool IsSatisfiedBy( T item ) {
+			return _criteria.IsSatisfiedBy( item );
+		}
+
+		public ISpecificationBuilder< T > And( ISpecification< T > specification ) {
+			_criteria = new AndSpecification< T >( _criteria, specification );
+			return this;
+		}
+
+		public ISpecification< T > Build() {
+			return _criteria;
+		}
+
+		public class BlankSpecification : ISpecification< T > {
+			public bool IsSatisfiedBy( T item ) {
+				return true;
+			}
+		}
+
+		private ISpecification< T > _criteria;
+
+		private class AndSpecification< K > : ISpecification< K > {
+			public AndSpecification( ISpecification< K > leftCriteria, ISpecification< K > rightCriteria ) {
+				this.leftCriteria = leftCriteria;
+				this.rightCriteria = rightCriteria;
+			}
+
+			public bool IsSatisfiedBy( K item ) {
+				return leftCriteria.IsSatisfiedBy( item ) && rightCriteria.IsSatisfiedBy( item );
+			}
+
+			private readonly ISpecification< K > leftCriteria;
+			private readonly ISpecification< K > rightCriteria;
+		}
+	}
+}
+\ No newline at end of file