add another test

examples/generic_pr/main.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+
+	"git.tuxpa.in/a/lambda"
+	"git.tuxpa.in/a/lambda/parallel"
+)
+
+type RequestContext[T any] struct {
+	req http.Request
+	ans T
+	err error
+}
+
+func (r *RequestContext[T]) String() string {
+	return fmt.Sprintf("%+v", r.ans)
+}
+
+func do[T any](r *RequestContext[T]) *RequestContext[T] {
+	r.ans = *new(T)
+	res, err := http.DefaultClient.Do(&r.req)
+	if err != nil {
+		r.err = err
+		return r
+	}
+	defer res.Body.Close()
+	r.err = json.NewDecoder(res.Body).Decode(&r.ans)
+	return r
+}
+
+type someResult struct {
+	Title string `json:"title"`
+	Id    int    `json:"id"`
+}
+
+func main() {
+	var requests = make([]*RequestContext[someResult], 20)
+	for i := range requests {
+		r, _ := http.NewRequest("GET", fmt.Sprintf("https://jsonplaceholder.typicode.com/todos/%d", i+1), nil)
+		requests[i] = &RequestContext[someResult]{
+			req: *r,
+		}
+	}
+	results := lambda.Filter(parallel.Map(requests, do[someResult], 4), func(r *RequestContext[someResult]) bool {
+		return r.err == nil
+	})
+	for _, v := range results {
+		log.Printf("%s", v)
+	}
+}