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

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

@@ -0,0 +1,53 @@
+package linq
+
+// Aggregate applies an accumulator function over a sequence.
+//
+// Aggregate method makes it simple to perform a calculation over a sequence of values.
+// This method works by calling f() one time for each element in source
+// except the first one. Each time f() is called, Aggregate passes both
+// the element from the sequence and an aggregated value (as the first argument to f()).
+// The first element of source is used as the initial aggregate value.
+// The result of f() replaces the previous aggregated value.
+//
+// Aggregate returns the final result of f().
+func (q Query) Aggregate(
+	f func(interface{}, interface{}) interface{}) interface{} {
+	next := q.Iterate()
+
+	result, any := next()
+	if !any {
+		return nil
+	}
+
+	for current, ok := next(); ok; current, ok = next() {
+		result = f(result, current)
+	}
+
+	return result
+}
+
+// AggregateWithSeed applies an accumulator function over a sequence.
+// The specified seed value is used as the initial accumulator value.
+//
+// Aggregate method makes it simple to perform a calculation over a sequence of values.
+// This method works by calling f() one time for each element in source
+// except the first one. Each time f() is called, Aggregate passes both
+// the element from the sequence and an aggregated value (as the first argument to f()).
+// The value of the seed parameter is used as the initial aggregate value.
+// The result of f() replaces the previous aggregated value.
+//
+// Aggregate returns the final result of f().
+func (q Query) AggregateWithSeed(
+	seed interface{},
+	f func(interface{}, interface{}) interface{},
+) interface{} {
+
+	next := q.Iterate()
+	result := seed
+
+	for current, ok := next(); ok; current, ok = next() {
+		result = f(result, current)
+	}
+
+	return result
+}