feat(Go-Tool)：2020/11/12:新增linq包使用示例(未完成)

vendor/github.com/ahmetalpbalkan/go-linq/intersect.go

@@ -0,0 +1,67 @@
+package linq
+
+// Intersect produces the set intersection of the source collection and the
+// provided input collection. The intersection of two sets A and B is defined as
+// the set that contains all the elements of A that also appear in B,
+// but no other elements.
+func (q Query) Intersect(q2 Query) Query {
+	return Query{
+		Iterate: func() Iterator {
+			next := q.Iterate()
+			next2 := q2.Iterate()
+
+			set := make(map[interface{}]bool)
+			for item, ok := next2(); ok; item, ok = next2() {
+				set[item] = true
+			}
+
+			return func() (item interface{}, ok bool) {
+				for item, ok = next(); ok; item, ok = next() {
+					if _, has := set[item]; has {
+						delete(set, item)
+						return
+					}
+				}
+
+				return
+			}
+		},
+	}
+}
+
+// IntersectBy produces the set intersection of the source collection and the
+// provided input collection. The intersection of two sets A and B is defined as
+// the set that contains all the elements of A that also appear in B,
+// but no other elements.
+//
+// IntersectBy invokes a transform function on each element of both collections.
+func (q Query) IntersectBy(
+	q2 Query,
+	selector func(interface{}) interface{},
+) Query {
+
+	return Query{
+		Iterate: func() Iterator {
+			next := q.Iterate()
+			next2 := q2.Iterate()
+
+			set := make(map[interface{}]bool)
+			for item, ok := next2(); ok; item, ok = next2() {
+				s := selector(item)
+				set[s] = true
+			}
+
+			return func() (item interface{}, ok bool) {
+				for item, ok = next(); ok; item, ok = next() {
+					s := selector(item)
+					if _, has := set[s]; has {
+						delete(set, s)
+						return
+					}
+				}
+
+				return
+			}
+		},
+	}
+}