emacs: avoid unnecessary let-bindings

To some extend this is a personal preference, but the preference is
strongly dependent on whether one is used to a language that makes it
necessary to use variables like this.

This makes it perfectly clear that we are first getting and then using
a "foo":

  (use-foo (get-foo))

Sure this has to be read "inside out", but that's something one better
gets used to quickly when dealing with lisp.  I don't understand why
one would want to write this instead:

  (let ((the-foo (get-foo)))
    (use-foo the-foo))

Both `get-foo' and `use-foo' are named in a way that make it very
clear that we are dealing with a "foo".  Storing the value in an
additional variable `the-foo' does not make this any more clear.

On the contrary I makes the reader wonder why the author choose to
use a variable.  Is the value used more than once?  Is the value
being retrieved in one context and then used in another (e.g. when
the current buffer changes)?

1 files changed, 24 insertions, 26 deletions

diff --git a/emacs/notmuch.el b/emacs/notmuch.el
index 40b730df..3436e1fc 100644
--- a/emacs/notmuch.el
+++ b/emacs/notmuch.el
@@ -521,17 +521,16 @@ With a prefix argument, invert the default value of
 `notmuch-show-only-matching-messages' when displaying the
 thread."
   (interactive "P")
-  (let ((thread-id (notmuch-search-find-thread-id))
-	(subject (notmuch-search-find-subject)))
-    (if (> (length thread-id) 0)
+  (let ((thread-id (notmuch-search-find-thread-id)))
+    (if thread-id
 	(notmuch-show thread-id
 		      elide-toggle
 		      (current-buffer)
 		      notmuch-search-query-string
 		      ;; Name the buffer based on the subject.
-		      (concat "*"
-			      (truncate-string-to-width subject 30 nil nil t)
-			      "*"))
+		      (format "*%s*" (truncate-string-to-width
+				      (notmuch-search-find-subject)
+				      30 nil nil t)))
       (message "End of search results."))))
 
 (defun notmuch-tree-from-search-current-query ()
@@ -556,20 +555,21 @@ thread."
 (defun notmuch-search-reply-to-thread (&optional prompt-for-sender)
   "Begin composing a reply-all to the entire current thread in a new buffer."
   (interactive "P")
-  (let ((message-id (notmuch-search-find-thread-id)))
-    (notmuch-mua-new-reply message-id prompt-for-sender t)))
+  (notmuch-mua-new-reply (notmuch-search-find-thread-id)
+			 prompt-for-sender t))
 
 (defun notmuch-search-reply-to-thread-sender (&optional prompt-for-sender)
   "Begin composing a reply to the entire current thread in a new buffer."
   (interactive "P")
-  (let ((message-id (notmuch-search-find-thread-id)))
-    (notmuch-mua-new-reply message-id prompt-for-sender nil)))
+  (notmuch-mua-new-reply (notmuch-search-find-thread-id)
+			 prompt-for-sender nil))
 
 ;;; Tags
 
 (defun notmuch-search-set-tags (tags &optional pos)
-  (let ((new-result (plist-put (notmuch-search-get-result pos) :tags tags)))
-    (notmuch-search-update-result new-result pos)))
+  (notmuch-search-update-result
+   (plist-put (notmuch-search-get-result pos) :tags tags)
+   pos))
 
 (defun notmuch-search-get-tags (&optional pos)
   (plist-get (notmuch-search-get-result pos) :tags))
@@ -1013,10 +1013,9 @@ the configured default sort order."
     (setq notmuch-search-target-thread target-thread)
     (setq notmuch-search-target-line target-line)
     (notmuch-tag-clear-cache)
-    (let ((proc (get-buffer-process (current-buffer)))
-	  (inhibit-read-only t))
-      (when proc
-	(error "notmuch search process already running for query `%s'" query))
+    (when (get-buffer-process buffer)
+      (error "notmuch search process already running for query `%s'" query))
+    (let ((inhibit-read-only t))
       (erase-buffer)
       (goto-char (point-min))
       (save-excursion
@@ -1045,13 +1044,12 @@ the new search results, then point will be placed on the same
 thread. Otherwise, point will be moved to attempt to be in the
 same relative position within the new buffer."
   (interactive)
-  (let ((target-line (line-number-at-pos))
-	(oldest-first notmuch-search-oldest-first)
-	(target-thread (notmuch-search-find-thread-id 'bare))
-	(query notmuch-search-query-string))
-    ;; notmuch-search erases the current buffer.
-    (notmuch-search query oldest-first target-thread target-line t)
-    (goto-char (point-min))))
+  (notmuch-search notmuch-search-query-string
+		  notmuch-search-oldest-first
+		  (notmuch-search-find-thread-id 'bare)
+		  (line-number-at-pos)
+		  t)
+  (goto-char (point-min)))
 
 (defun notmuch-search-toggle-order ()
   "Toggle the current search order.
@@ -1160,9 +1158,9 @@ Used as`imenu-prev-index-position-function' in notmuch buffers."
   "Return imenu name for line at point.
 Used as `imenu-extract-index-name-function' in notmuch buffers.
 Point should be at the beginning of the line."
-  (let ((subject (notmuch-search-find-subject))
-	(author (notmuch-search-find-authors)))
-    (format "%s (%s)" subject author)))
+  (format "%s (%s)"
+	  (notmuch-search-find-subject)
+	  (notmuch-search-find-authors)))
 
 ;;; _