From 30d33b414893290c55b585e40c8085abd2d1556f Mon Sep 17 00:00:00 2001
From: Panagiotis Koutsourakis <panagiotis.koutsourakis@gmail.com>
Date: Fri, 16 Mar 2012 01:22:13 +0100
Subject: [PATCH] Several improvements.

Added code to autoload drakma and cl-json (requires quicklisp).
Added documentation strings to functions.
Added white and black list support.
Added a function to pick parts of the tweets.
---
 twitter-filter.lisp | 59 +++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 53 insertions(+), 6 deletions(-)

diff --git a/twitter-filter.lisp b/twitter-filter.lisp
index e0bd888..1b91daf 100644
--- a/twitter-filter.lisp
+++ b/twitter-filter.lisp
@@ -1,17 +1,22 @@
+(ql:quickload "drakma")
+(ql:quickload "cl-json")
+
 (defpackage :twitter-filter
-  (:use :cl :drakma :json))
+  (:use :cl :drakma :json)
+  (:export :parse-query))
 
 (in-package :twitter-filter)
 
-(defun convert-response-to-string (resp)
-  (coerce (mapcar #'code-char (coerce resp 'list)) 'string))
-
 (defparameter *search-url* "http://search.twitter.com/search.json?q=")
 
-(defun make-query (search-term)
-  (http-request (concatenate 'string *search-url* (percent-encode search-term))))
+(defun convert-response-to-string (resp)
+  "The server response is an array of integers. This function converts
+it to a string."
+  (coerce (mapcar #'code-char (coerce resp 'list)) 'string))
 
 (defun percent-encode (str)
+  "Make the string percent encoded in order to be compatible with
+URLs."
   (labels ((percent-encode-char-list (char-list)
              (let ((curr (car char-list))
                    (rest (cdr char-list)))
@@ -23,8 +28,50 @@
                  (t (cons curr (percent-encode-char-list rest)))))))
     (coerce (percent-encode-char-list (coerce str 'list)) 'string)))
 
+(defun make-query (search-term)
+  "Make the actual search query to the twitter API."
+  (http-request (concatenate 'string *search-url* (percent-encode search-term))))
+
 
 (defun parse-query (search-term)
+  "Convert the response to Lisp objects using cl-json library."
   (with-input-from-string 
       (s (convert-response-to-string (make-query search-term)))
     (decode-json s)))
+
+(defparameter *white-list-mode* nil)
+(defparameter *black-list-mode* nil)
+
+(defvar *white-list* nil)
+(defvar *black-list* nil)
+
+;TODO: explore if these two can be written with a macro.
+(defun black-list (lisp-tweets)
+  "Remove a tweet if the user is a member of *black-list*"
+  (if *black-list-mode*
+      (remove-if (lambda (x)
+                   (member (cdr (assoc :from--user x))
+                           *black-list* :test #'equal))
+                 lisp-tweets)
+      lisp-tweets))
+
+(defun white-list (lisp-tweets)
+  "Remove a tweet if the user is NOT a member of *white-list*"
+  (if *white-list-mode*
+      (remove-if (lambda (x)
+                   (not (member (cdr (assoc :from--user x))
+                                *white-list* :test #'equal)))
+                 lisp-tweets)
+      lisp-tweets))
+
+(defun get-tweet-element-list (lisp-tweets element)
+  "Make a list with one element from each tweet from lisp-tweets."
+  (mapcar (lambda (x) (cdr (assoc element x))) lisp-tweets))
+
+(defun apply-lists (lisp-tweets)
+  "Apply the functions white-list and black-list"
+  (black-list (white-list lisp-tweets)))
+
+;Not strictly necessary... Just a reminder.
+(defun convert-tweets-to-json (lisp-tweets)
+  (encode-json lisp-tweets))
-- 
2.11.4.GIT