如何在clojure中使用twitter-api獲取流媒體推文？

Question

我是clojure的新手。我正在嘗試通過clojure獲取流媒體推文。我使用twitter-api庫來獲取流媒體推文，代碼片段如下。

(ns hello-twitter 
    (:use 
    [twitter.oauth] 
    [twitter.callbacks] 
    [twitter.callbacks.handlers] 
    [twitter.api.streaming]) 
    (:require 
    [clojure.data.json :as json] 
    [http.async.client :as ac]) 
    (:import 
    (twitter.callbacks.protocols AsyncStreamingCallback))) 

(def my-creds (make-oauth-creds "app consumer key" 
           "app consumer secret" 
           "user-access-token" 
           "user-access-token-secret")) 

(def ^:dynamic 
    *custom-streaming-callback* 
    (AsyncStreamingCallback. (comp println #(:text %) json/read-json #(str %2)) 
         (comp println response-return-everything) 
        exception-print)) 

(statuses-filter :params {:track "Cricket"} 
     :oauth-creds my-creds 
     :callbacks *custom-streaming-callback*) 

返回的json中的body部分應該不斷更新。我得到的價值：身體就像<core$promise$reify__6363@32cdfb83: :pending>，我無法弄清楚如何得到推文。

如何建立不間斷連接以獲取流式tweets輸出？

Answer 1

此值爲promise。不是在通過網絡發送請求時阻塞線程，而是創建一個承諾並將其返回給您，以便您的程序可以繼續執行。稍後的承諾需要用deref或@取消引用以獲取該值。

實施例從鏈接的文檔複製：

;; Create a promise 
user> (def p (promise)) 
#'user/p ; p is our promise 

;; Check if was delivered/realized 
user> (realized? p) 
false ; No yet 

;; Delivering the promise 
user> (deliver p 42) 
#<core$promise$reify__5727@47122d: 42> 

;; Check again if it was delivered 
user> (realized? p) 
true ; Yes! 

;; Deref to see what has been delivered 
user> @p 
42 

;; Note that @ is shorthand for deref 
user> (deref p) 
42