Emacs: check for existence for loading, to avoid error.

.emacs.d/plugins.el

@@ -3,7 +3,7 @@
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
 ;; User plugin path.
-(add-to-list 'load-path "~/.emacs.d/plugins")
+;; (add-to-list 'load-path "~/.emacs.d/plugins")
 
 ;;==============================================================================
 ;; Yasnippet
@@ -17,11 +17,11 @@
 
 ;; Next follows a traditional, yet not-optimized configuration for Yasnippet.
 ;; (add-to-list 'load-path "/usr/share/emacs/site-lisp/yas")
-(require 'yasnippet) ;; not yasnippet-bundle
+(if (require 'yasnippet nil t)
+    (progn
+     (setq yas-snippet-dirs "~/.emacs.d/snippets" )
 
-(setq yas-snippet-dirs "~/.emacs.d/snippets" )
-
-(if (fboundp 'yas/initialize)
+     (if (fboundp 'yas/initialize)
          ;; Old yasnippet versions.
          (progn
            (yas/initialize)
@@ -31,8 +31,10 @@
        (progn
          (yas-global-mode 1)
          (yas-load-directory yas-snippet-dirs))
-)
 
+       )
+
+     ))
 
 ;;==============================================================================
 ;; Lua
@@ -44,33 +46,34 @@
 ;; MediaWiki
 ;;==============================================================================
 
-(require 'mediawiki)
+(if (require 'mediawiki nil t)
+    (progn
 
-;; Macros.
-;; Use C-( stuff C-) to record a macro.
-;; Use 'name-last-kbd-macro' to give it a name.
-;; Use 'insert-kbd-macro' in your init file to insert the code.
-;; You can assign a key: (local-set-key (kbd "C-c a") 'my-macro)
-(fset 'ltx-template-source-to-latex
-   "\C-@\C-s>\C-m\C-w\C-@\C-s</source\C-m\C-[Od\C-[[D\C-[[D\C-wltx\C-i\C-y\C-i\C-[d\C-d")
-
-(fset 'ltx-template-source-to-usage
-      "\C-@\C-s>\C-w\C-?\C-m\C-w\C-d\C-@\C-s</source\C-m\C-[Od\C-[[D\C-[[D\C-[[D\C-wltxu\C-i\C-y\C-i\C-k\C-k")
-
-(setq mediawiki-site-alist
+     (setq mediawiki-site-alist
            '(
              ("Wikipedia" "http://en.wikipedia.org/w/" "Ambrevar" "" "Main Page")
              ("Wikibooks" "http://en.wikibooks.org/w/" "Ambrevar" "" "LaTeX")
              ("ArchLinux" "https://wiki.archlinux.org/" "Ambrevar" "" "Mutt"))
            )
 
-;; The url-cookie timer is set to a high value because it seems that once the
-;; cookie has been saved, MediaWiki fails to upload files correctly.  Is
-;; 'url-do-setup' needed to make sure the url-cookie-save-interval variable is
-;; taken into account? TODO: does not work.
-(setq url-cookie-save-interval 86400)
+     ;; Macros.
+     ;; Use C-( stuff C-) to record a macro.
+     ;; Use 'name-last-kbd-macro' to give it a name.
+     ;; Use 'insert-kbd-macro' in your init file to insert the code.
+     ;; You can assign a key: (local-set-key (kbd "C-c a") 'my-macro)
+     (fset 'ltx-template-source-to-latex
+           "\C-@\C-s>\C-m\C-w\C-@\C-s</source\C-m\C-[Od\C-[[D\C-[[D\C-wltx\C-i\C-y\C-i\C-[d\C-d")
 
-(setq mediawiki-mode-hook
+     (fset 'ltx-template-source-to-usage
+           "\C-@\C-s>\C-w\C-?\C-m\C-w\C-d\C-@\C-s</source\C-m\C-[Od\C-[[D\C-[[D\C-[[D\C-wltxu\C-i\C-y\C-i\C-k\C-k")
+
+     ;; The url-cookie timer is set to a high value because it seems that once the
+     ;; cookie has been saved, MediaWiki fails to upload files correctly.  Is
+     ;; 'url-do-setup' needed to make sure the url-cookie-save-interval variable is
+     ;; taken into account? TODO: does not work.
+     (setq url-cookie-save-interval 86400)
+
+     (setq mediawiki-mode-hook
            (lambda ()
              (visual-line-mode 1)
              (turn-off-auto-fill)
@@ -80,7 +83,9 @@
              ;; TODO: Bindings to not work???
              ;; (local-set-key (kbd "C-c l L") 'ltx-template-source-to-latex)
              ;; (local-set-key (kbd "C-c l U") 'ltx-template-source-to-usage)
-))
+             ))
+
+     ))
 
 ;;==============================================================================
 ;; DoxyMacs
@@ -101,8 +106,8 @@
 ;;==============================================================================
 ;; Zsh style completion.
 
-(require 'zlc)
-(let ((map minibuffer-local-map))
+(if (require 'zlc nil t)
+    (let ((map minibuffer-local-map))
       ;; Like Zsh menu select.  Should not use arrows directly because it overrides
       ;; default controls like previous entry, or previous/next char.
       (define-key map (kbd "C-<down>")  'zlc-select-next-vertical)
@@ -110,10 +115,11 @@
       (define-key map (kbd "C-<right>") 'zlc-select-next)
       (define-key map (kbd "C-<left>")  'zlc-select-previous)
 
-  ;;; Reset selection.
+      ;; Reset selection.
       (define-key map (kbd "C-c") 'zlc-reset)
+
+      ;; (setq zlc-select-completion-immediately t)
+
+      ;; To change style, M-x customize-face and input zlc-selected-completion-face.
       )
-
-;; (setq zlc-select-completion-immediately t)
-
-;; To change style, M-x customize-face and input zlc-selected-completion-face.
+)