1 files changed, 102 insertions, 0 deletions
diff --git a/sx-filter.el b/sx-filter.el
new file mode 100644
index 0000000..7178259
--- /dev/null
+++ b/sx-filter.el
@@ -0,0 +1,102 @@
+;;; sx-filter.el --- filters                         -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2014  Sean Allred
+
+;; Author: Sean Allred <code@seanallred.com>
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;
+
+;;; Code:
+
+
+;;; Dependencies
+
+(require 'sx)
+(require 'sx-cache)
+
+
+;;; Customizations
+
+(defconst sx-filter-cache-file
+  "filters.el")
+
+(defvar sx-filter
+  'default
+  "The current filter.
+To customize the filter for the next call to `sx-request-make',
+let-bind this variable to the output of a call to
+`sx-filter-compile'.  Be careful!  If you're going to be using
+this new filter a lot, create a variable for it.  Creation
+requests count against `sx-request-remaining-api-requests'!")
+
+
+;;; Compilation
+
+;;; TODO allow BASE to be a precompiled filter name
+(defun sx-filter-compile (&optional include exclude base)
+  "Compile INCLUDE and EXCLUDE into a filter derived from BASE.
+
+INCLUDE and EXCLUDE must both be lists; BASE should be a symbol
+or string."
+  (let ((keyword-arguments
+         `((include . ,(if include (sx--thing-as-string include)))
+           (exclude . ,(if exclude (sx--thing-as-string exclude)))
+           (base    . ,(if base base)))))
+    (let ((response (sx-request-make
+                     "filter/create"
+                     keyword-arguments)))
+      (url-hexify-string
+       (cdr (assoc 'filter
+                   (elt response 0)))))))
+
+
+;;; Storage and Retrieval
+
+(defun sx-filter-get (filter)
+  "Retrieve named FILTER from `sx-filter-cache-file'."
+  (cdr (assoc filter (sx-cache-get sx-filter-cache-file))))
+
+(defun sx-filter-store (name &optional filter)
+  "Store NAME as FILTER in `sx-filter-cache-file'.
+
+NAME should be a symbol and FILTER is a string as compiled by
+`sx-filter-compile'.
+
+If NAME is a cons cell, (car NAME) is taken to be the actual NAME
+and (cdr NAME) is taken to be the actual FILTER.  In this case,
+the second argument is simply ignored."
+  (let ((name   (if (consp name) (car name) name))
+        (filter (if (consp name) (cdr name) filter)))
+    (unless (symbolp name)
+      (error "Name must be a symbol: %S" name))
+    (let* ((dict (sx-cache-get sx-filter-cache-file))
+           (entry (assoc name dict)))
+      (if entry (setcdr entry filter)
+        (setq dict (cons (cons name filter) dict)))
+
+      (sx-cache-set sx-filter-cache-file dict))))
+
+(defun sx-filter-store-all (name-filter-alist)
+  (mapc #'sx-filter-store name-filter-alist))
+
+(provide 'sx-filter)
+;;; sx-filter.el ends here
+
+;; Local Variables:
+;; indent-tabs-mode: nil
+;; End: