[notmuch] [PATCH v3] notmuch-query.el: new file to support access to the notmuch database.

[david at tethera.net]

From: David Bremner <bremner at unb.ca>

Initially this file provides one main function
notmuch-query-get-threads, which takes a set of search terms, and
returns a parsed set of matching threads as a lisp data structure.

A set of notmuch-query-map-* functions are provided to help map
functions over the data structure.

The function notmuch-query-get-message-ids uses this machinery to get
the set of message-ids matching a query.
---

Commentary on this revision of the patch.
	- Rebased to current master.
	- Last time I checked, used by dme's json rewrite of the emacs ui
        - Warnings eliminated by including the new notmuch-lib.el

 emacs/Makefile.local   |    1 +
 emacs/notmuch-query.el |   90 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 91 insertions(+), 0 deletions(-)
 create mode 100644 emacs/notmuch-query.el

diff --git a/emacs/Makefile.local b/emacs/Makefile.local
index 95b6fa4..626a4e5 100644
--- a/emacs/Makefile.local
+++ b/emacs/Makefile.local
@@ -4,6 +4,7 @@ dir := emacs
 emacs_sources := \
 	$(dir)/notmuch-lib.el \
 	$(dir)/notmuch.el \
+	$(dir)/notmuch-query.el \
 	$(dir)/notmuch-show.el
 
 emacs_bytecode := $(subst .el,.elc,$(emacs_sources))
diff --git a/emacs/notmuch-query.el b/emacs/notmuch-query.el
new file mode 100644
index 0000000..3f1a7b3
--- /dev/null
+++ b/emacs/notmuch-query.el
@@ -0,0 +1,90 @@
+; notmuch-query.el --- provide an emacs api to query notmuch
+;
+; Copyright © David Bremner
+;
+; This file is part of Notmuch.
+;
+; Notmuch 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.
+;
+; Notmuch 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 Notmuch.  If not, see <http://www.gnu.org/licenses/>.
+;
+; Authors: David Bremner <david at tethera.net>
+
+(require 'notmuch-lib)
+(require 'json)
+
+(defun notmuch-query-get-threads (search-terms &rest options)
+  "Return a list of threads of messages matching SEARCH-TERMS.
+
+A thread is a forest or list of trees. A tree is a two element
+list where the first element is a message, and the second element
+is a possibly empty forest of replies.
+"
+  (let  ((args (append '("show" "--format=json") search-terms))
+	 (json-object-type 'plist)
+	 (json-array-type 'list)
+	 (json-false 'nil))
+    (with-temp-buffer
+      (progn
+	(apply 'call-process (append (list notmuch-command nil t nil) args))
+	(goto-char (point-min))
+	(json-read)))))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Mapping functions across collections of messages.
+
+(defun notmuch-query-map-aux  (mapper function seq)
+  "private function to do the actual mapping and flattening"
+
+  (apply 'append
+	 (mapcar
+	   (lambda (tree)
+	     (funcall mapper fn tree))
+	   seq)))
+
+
+(defun notmuch-query-map-threads (fn threads)
+  "apply FN to every thread in  THREADS. Flatten results to a list.
+
+See the function notmuch-query-get-threads for more information."
+
+  (notmuch-query-map-aux 'notmuch-query-map-forest fn threads))
+
+
+(defun notmuch-query-map-forest (fn forest)
+  "apply function to every message in a forest. Flatten results to a list.
+
+See the function notmuch-query-get-threads for more information.
+"
+
+  (notmuch-query-map-aux 'notmuch-query-map-tree fn forest))
+
+
+(defun notmuch-query-map-tree (fn tree)
+  "Apply function FN to every message in TREE. Flatten results to a list
+
+See the function notmuch-query-get-threads for more information."
+
+  (cons (funcall fn (car tree)) (notmuch-query-map-forest fn (cadr tree))))
+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Predefined queries
+
+(defun notmuch-query-get-message-ids (&rest search-terms)
+  "Return a list of message-ids of messages that match SEARCH-TERMS"
+
+  (notmuch-query-map-threads
+   (lambda (msg) (plist-get msg :id))
+   (notmuch-query-get-threads search-terms)))
+
+(provide 'notmuch-query)
-- 
1.7.0