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

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

@@ -0,0 +1,46 @@
+package linq
+
+// Where filters a collection of values based on a predicate.
+func (q Query) Where(predicate func(interface{}) bool) Query {
+	return Query{
+		Iterate: func() Iterator {
+			next := q.Iterate()
+
+			return func() (item interface{}, ok bool) {
+				for item, ok = next(); ok; item, ok = next() {
+					if predicate(item) {
+						return
+					}
+				}
+
+				return
+			}
+		},
+	}
+}
+
+// WhereIndexed filters a collection of values based on a predicate.
+// Each element's index is used in the logic of the predicate function.
+//
+// The first argument represents the zero-based index of the element within collection.
+// The second argument of predicate represents the element to test.
+func (q Query) WhereIndexed(predicate func(int, interface{}) bool) Query {
+	return Query{
+		Iterate: func() Iterator {
+			next := q.Iterate()
+			index := 0
+
+			return func() (item interface{}, ok bool) {
+				for item, ok = next(); ok; item, ok = next() {
+					if predicate(index, item) {
+						return
+					}
+
+					index++
+				}
+
+				return
+			}
+		},
+	}
+}