[Emacs] Move packages configuration to a new file.

Keep `init.el` as small as possible, and move all the packages to
their own configuration file.

3 files changed, 428 insertions, 458 deletions

diff --git a/emacs.d/init.el b/emacs.d/init.el
index cfff32d..440a879 100644
--- a/emacs.d/init.el
+++ b/emacs.d/init.el
@@ -1,460 +1,14 @@
-;; setup packages
-(require 'package)
-(setq package-user-dir (expand-file-name "var/elpa" user-emacs-directory)
-      package-enable-at-startup nil
-      package-archives (append package-archives
-                               '(("melpa" . "https://melpa.milkbox.net/packages/"))))
-
-(package-initialize)
-
-(unless package-archive-contents
-  (message "Refreshing ELPA package archives...")
-  (package-refresh-contents))
-
-;; install the package 'use-package' unless it's already installed
-(unless (package-installed-p 'use-package)
-  (progn
-    (package-install 'use-package)))
-
-;; ... and load 'use-package'
-(require 'use-package)
-
-(use-package settings
-  :load-path (lambda () (expand-file-name  "lib" user-emacs-directory)))
-
-(use-package funcs
-  ;; Contains some functions
-  :load-path (lambda () (expand-file-name  "lib" user-emacs-directory))
-  :commands (fc/load-time)
-  :bind (("s-=" . fc/scale-up-font)
-         ("s--" . fc/scale-down-font)
-         ("s-0" . fc/reset-font-size)))
-
-(use-package bindings
-  ;; my own custom bindings
-  :load-path (lambda () (expand-file-name  "lib" user-emacs-directory)))
-
-(use-package server
-  ;; start emacs server if not already running
-  :config
-  (unless (server-running-p) (server-start)))
-
-(use-package  diminish
-  ;; remove clutter from the mode line
-  :ensure t)
-
-(use-package ag
-  ;; interface to the 'ag' tool
-  :ensure t
-  :commands (counsel-ag ag)
-  :bind (:map ag-mode-map
-              ("p" . compilation-previous-error)
-              ("n" . compilation-next-error)
-              ("N" . compilation-next-file)
-              ("P" . compilation-previous-file))
-  :config
-  (setq ag-highlight-search t
-        ag-reuse-buffers t
-        ag-reuse-window t))
-
-(use-package autorevert
-  ;; automatically revert the buffer if the content changed on disk
-  :diminish auto-revert-mode)
-
-(use-package company
-  ;; provide completion
-  :ensure t
-  :config
-  (global-company-mode))
-
-(use-package company-go
-  :ensure t
-  ;; completion for golang
-  :init (with-eval-after-load 'company
-          (add-to-list 'company-backends 'company-go)))
-
-(use-package counsel
-  ;; completion functions for ivy
-  :ensure t
-
-  :bind*
-  (("M-x"     . counsel-M-x)
-   ("C-s"     . counsel-grep-or-swiper)
-   ("C-x C-f" . counsel-find-file)
-   ("C-x C-r" . counsel-recentf)
-   ("C-c f"   . counsel-git)
-   ("C-c s"   . counsel-git-grep)
-   ("C-c /"   . counsel-ag))
-
-  :config
-  (setq counsel-find-file-at-point t))
-
-(use-package dired
-  ;; configuration for dired
-  :bind ("C-x C-d" . dired)
-
-  :config
-  (let ((gls "/opt/twitter/bin/gls"))
-    (if (file-exists-p gls)
-        (setq insert-directory-program gls
-              dired-listing-switches "-aBhl --group-directories-first")))
-  (use-package dired-x
-    :init
-    (add-hook 'dired-load-hook (lambda () (load "dired-x")))
-    :config
-    (add-hook 'dired-mode-hook #'dired-omit-mode)
-    (setq dired-omit-verbose nil)
-    (setq dired-omit-files
-          (concat dired-omit-files "\\|^.DS_Store$\\|^.projectile$\\|^.git$"))))
-
-(use-package dockerfile-mode
-  ;; support for dockerfile mode
-  :ensure t)
-
-(use-package lisp-mode
-  ;; simple configuration for various lisp mode
-  :config
-  (add-hook 'emacs-lisp-mode-hook
-            (lambda()
-              (setq mode-name "λ"))))
-
-(use-package eldoc
-  ;; documentation with eldoc
-  :ensure t
-
-  :commands eldoc-mode
-
-  :diminish ""
-
-  :init
-  (add-hook 'emacs-lisp-mode-hook 'eldoc-mode)
-  (add-hook 'lisp-interaction-mode-hook 'eldoc-mode))
-
-(use-package exec-path-from-shell
-  ;; environment fixup for macOS.
-  :ensure t
-
-  :if (and (eq system-type 'darwin) (display-graphic-p))
-
-  :init
-  (setq exec-path-from-shell-check-startup-files nil)
-
-  :config
-  (progn
-    (setq exec-path-from-shell-debug t)
-    (exec-path-from-shell-initialize)))
-
-(use-package flycheck
-  ;; check syntax
-  :ensure t
-
-  :config
-  (progn
-
-    (add-hook 'prog-mode-hook 'flycheck-mode)
-
-    (setq-default flycheck-disabled-checkers '(emacs-lisp-checkdoc))
-    (setq flycheck-highlighting-mode 'lines)
-    (setq flycheck-check-syntax-automatically '(mode-enabled save))))
-
-(use-package flyspell
-  ;; check the spelling
-  :ensure t
-
-  :init
-  (progn
-    (setq ispell-program-name "aspell"
-          ispell-list-command "--list")
-    (add-hook 'text-mode-hook 'flyspell-mode))
-
-  :config
-  (use-package flyspell-popup
-    :ensure t
-    :bind ("C-:" . flyspell-popup-correct)))
-
-(use-package geiser
-  ;; to work with various schemes
-  :ensure t
-
-  :config
-  (progn
-    (setq geiser-default-implementation 'racket
-          geiser-racket-binary "~/src/devbox/racket/racket-repl.sh")))
-
-(use-package go-mode
-  ;; support for go
-  :mode (("\\.go\\'" . go-mode))
-
-  :ensure t
-
-  :config
-  (progn
-    (when (memq window-system '(mac ns x))
-      (dolist (var '("GOPATH"))
-        (unless (getenv var)
-          (exec-path-from-shell-copy-env var))))
-
-    (use-package go-eldoc
-      :ensure t
-      :config
-      (add-hook 'go-mode-hook 'go-eldoc-setup))
-
-    (use-package gotest
-      :ensure t)
-
-    (use-package go-guru
-      :ensure t)
-
-    (defun fc/my-go-hook ()
-      (set (make-local-variable 'compile-command)
-           "go build -v && go test -v && go vet")
-      (setq-local tab-width 4)
-      (make-variable-buffer-local 'whitespace-style)
-      (setq whitespace-style (delq 'tabs whitespace-style)))
-
-    (add-hook 'before-save-hook 'gofmt-before-save)
-    (add-hook 'go-mode-hook 'fc/my-go-hook)))
-
-(use-package ibuffer
-  ;; configuration for ibuffer
-  :ensure t
-  :defer t
-  :bind ("C-x C-b" . ibuffer)
-  :init
-  (setq-default ibuffer-eliding-string "…")
-  (setq ibuffer-show-empty-filter-groups nil
-        ibuffer-formats '((mark modified read-only " "
-                                (name 30 30 :left :elide)
-                                " "
-                                (size 9 -1 :right)
-                                " "
-                                (mode 16 16 :left :elide)
-                                " " filename-and-process)
-                          (mark " "
-                                (name 16 -1)
-                                " " filename))
-        ibuffer-saved-filter-groups
-        (quote (("default"
-                 ("dired"  (mode . dired-mode))
-                 ("elisp"  (mode . emacs-lisp-mode))
-                 ("emacs"  (or (name . "^\\*.*\\*$") (mode . fundamental-mode)))
-                 ("go"     (mode . go-mode))
-                 ("java"   (mode . java-mode))
-                 ("json"   (mode . json-mode))
-                 ("lisp"   (mode . lisp-mode))
-                 ("magit"  (mode . magit-mode))
-                 ("puppet" (mode . puppet-mode))
-                 ("python" (mode . python-mode))
-                 ("repl"   (name . "repl"))
-                 ("ruby"   (mode . ruby-mode))
-                 ("sh"     (mode . sh-mode))
-                 ("text"   (mode . text-mode))))))
-
-  (add-hook 'ibuffer-mode-hook  ;; organise by filter-groups
-            '(lambda ()
-               (ibuffer-auto-mode 1)
-               (setq mode-name "≣")
-               (ibuffer-switch-to-saved-filter-groups "default"))))
-
-(use-package ivy
-  ;; completion system
-  :diminish (ivy-mode . "")
-
-  :bind ("C-c m" . ivy-switch-project)
-
-  :config
-  (ivy-mode 1)
-  (setq ivy-use-virtual-buffers t
-        ivy-height 10
-        ivy-count-format "(%d/%d) "
-        ivy-initial-inputs-alist nil
-        ivy-use-ignore-default 'always
-        ivy-ignore-buffers '("company-statistics-cache.el" "company-statistics-autoload.el")
-        ivy-re-builders-alist '((swiper . ivy--regex-ignore-order)
-                                (t      . ivy--regex-fuzzy)
-                                (t      . ivy--regex-ignore-order)))
-
-  (defun ivy-switch-project ()
-    (interactive)
-    (ivy-read
-     "Switch to project: "
-     (if (projectile-project-p)
-         (cons (abbreviate-file-name (projectile-project-root))
-               (projectile-relevant-known-projects))
-       projectile-known-projects)
-     :action #'projectile-switch-project-by-name))
-
-  (ivy-set-actions
-   'ivy-switch-project
-   '(("d" dired "Open Dired in project's directory")
-     ("v" counsel-projectile "Open project root in vc-dir or magit")
-     ("c" projectile-compile-project "Compile project")
-     ("r" projectile-remove-known-project "Remove project(s)"))))
-
-(use-package json-mode
-  ;; mode to support json files
-  :ensure t
-
-  :mode "\\.json\\'"
-
-  :config
-  (setq json-reformat:indent-width 2))
-
-(use-package magit
-  ;; interface to git
-  :ensure t
-
-  :mode (("differential-update-comments" . git-commit-mode)
-         ("new-commit"                   . git-commit-mode))
-
-  :bind (("C-x g s" . magit-status)
-         ("C-x g b" . magit-checkout))
-
-  :init
-  (progn
-    (setq magit-completing-read-function 'ivy-completing-read))
-
-  :config
-  (progn
-    (global-git-commit-mode)
-    (use-package git-commit :ensure t :defer t)
-    (add-hook 'magit-mode-hook
-              (lambda()
-                (setq mode-name "⎇")))
-    (add-hook 'magit-log-edit-mode-hook
-              #'(lambda ()
-                  (set-fill-column 72)
-                  (flyspell-mode)))))
-
-(use-package make-mode
-  ;; mode to support Makefile
-  :config
-  (add-hook 'makefile-mode-hook (lambda ()
-                                  (setq-local tab-width 2))))
-
-(use-package markdown-mode
-  ;; mode to support files in the Markdown format
-  :ensure t
-
-  :commands (markdown-mode gfm-mode)
-
-  :mode (("\\.md\\'"       . gfm-mode)
-         ("\\.markdown\\'" . gfm-mode))
-
-  :init (setq markdown-command "pandoc -f markdown_github -c https://goo.gl/OVmlwT --self-contained")
-
-  :config
-  (add-hook 'gfm-mode-hook 'visual-line-mode))
-
-(use-package midnight
-  ;; clean old buffers at midnight
-  :ensure t
-  :config
-  (midnight-mode t))
-
-(use-package org
-  :defer t
-  :init
-  (progn
-    (setq org-startup-indented t)
-    (org-babel-do-load-languages 'org-babel-load-languages
-                                 '(
-                                   (sh . t))))
-  :config
-  (add-hook 'org-mode-hook #'(lambda ()
-                               (visual-line-mode)
-                               (org-indent-mode))))
-
-;; (use-package phabricator
-;;   ;; interface to phabricator
-;;   :load-path (lambda () (expand-file-name  "~/src/phabricator.el/"))
-
-;;   :config
-;;   (setq diffusion-repo-prefix-list '(("source" "source"))))
-
-(use-package projectile
-  ;; library to interact with projects
-  :ensure t
-
-  :diminish ""
-
-  :bind-keymap ("C-c p" . projectile-command-map)
-
-  :init
-  (add-hook 'after-init-hook #'projectile-mode)
-
-  :config
-  (use-package counsel-projectile :ensure t)
-  (setq projectile-switch-project-action 'projectile-dired
-        projectile-enable-caching t
-        projectile-completion-system 'ivy
-        projectile-known-projects-file (expand-file-name "var/projectile-bookmarks.eld" user-emacs-directory)
-        projectile-cache-file (expand-file-name "var/projectile.cache" user-emacs-directory))
-  (add-to-list 'projectile-globally-ignored-files ".DS_Store"))
-
-(use-package python
-  ;; configuration for Python
-  :mode(("\\.aurora$" . python-mode)
-        ("BUILD$"     . python-mode)
-        ("\\.py$"     . python-mode))
-
-  :interpreter ("python" . python-mode)
-
-  :init
-  (setq-default indent-tabs-mode nil)
-
-  :config
-  (setq python-indent-offset 2)
-  (add-hook 'python-mode-hook 'eldoc-mode t))
-
-(use-package recentf
-  ;; configuration for recentf, to interact with recent files
-  :config
-  (setq recentf-save-file (expand-file-name "var/recentf" user-emacs-directory)))
-
-(use-package sh-script
-  ;; configuration to interact with shell scripts
-  :mode ("bashrc" . sh-mode)
-
-  :config
-  (defun set-sh-mode-indent ()
-    (setq sh-basic-offset 2
-          sh-indentation 2))
-  (add-hook 'sh-mode-hook 'set-sh-mode-indent)
-  (add-hook 'after-save-hook 'executable-make-buffer-file-executable-if-script-p))
-
-(use-package swiper
-  ;; install swiper
-  :ensure t)
-
-(use-package tramp
-  ;; configuration for tramp
-  :config
-  (setq tramp-default-method "ssh"
-        tramp-persistency-file-name (expand-file-name "var/tramp" user-emacs-directory)))
-
-(use-package wabi-sabi-theme
-  ;; this is my own custom theme. No syntax highlighting
-  :load-path (lambda () (expand-file-name  "lib" user-emacs-directory))
-  :config
-  (load-theme 'wabi-sabi t))
-
-(use-package whitespace
-  ;; highlight white spaces
-  :config
-  (setq whitespace-style '(face trailing tabs))
-  (add-hook 'prog-mode-hook 'whitespace-mode))
-
-(use-package yaml-mode
-  ;; mode to work wity YAML files
-  :ensure t
-
-  :init (add-hook 'yaml-mode-hook 'flycheck-mode)
-
-  :mode ("\\.ya?ml\\'" . yaml-mode))
-
-(use-package twitter
-  ;; finish by loading twitter's modules
-  :load-path (lambda () (expand-file-name  "lib" user-emacs-directory)))
+;; If this is not commented, Emacs will overwrite this configuration file
+;; on load time.
+;; (package-initialize)
+
+(defun emacs-lib (filename)
+  (expand-file-name (concat "lib" "/" filename) user-emacs-directory))
+
+(load (emacs-lib "settings.el"))
+(load (emacs-lib "funcs.el"))
+(load (emacs-lib "bindings.el"))
+(load (emacs-lib "packages.el"))
+(load (emacs-lib "twitter.el") 'missing-ok)
 
 (add-hook 'emacs-startup-hook #'fc/load-time)
diff --git a/emacs.d/lib/bindings.el b/emacs.d/lib/bindings.el
index 2320fb5..ec97ecc 100644
--- a/emacs.d/lib/bindings.el
+++ b/emacs.d/lib/bindings.el
@@ -5,4 +5,8 @@
 (define-key emacs-lisp-mode-map (kbd "C-c C-e") 'eval-buffer)
 (define-key emacs-lisp-mode-map (kbd "C-c C-r") 'eval-region)
 
+(global-set-key (kbd "s-=") 'fc/scale-up-font)
+(global-set-key (kbd "s--") 'fc/scale-down-font)
+(global-set-key (kbd "s-0") 'fc/reset-font-size)
+
 (provide 'bindings)
diff --git a/emacs.d/lib/packages.el b/emacs.d/lib/packages.el
new file mode 100644
index 0000000..dfbdb37
--- /dev/null
+++ b/emacs.d/lib/packages.el
@@ -0,0 +1,412 @@
+;; setup packages
+(require 'package)
+(setq package-user-dir (expand-file-name "var/elpa" user-emacs-directory)
+      package-enable-at-startup nil
+      package-archives (append package-archives
+                               '(("melpa" . "https://melpa.milkbox.net/packages/"))))
+
+(package-initialize)
+
+(unless package-archive-contents
+  (message "Refreshing ELPA package archives...")
+  (package-refresh-contents))
+
+;; install the package 'use-package' unless it's already installed
+(unless (package-installed-p 'use-package)
+  (progn
+    (package-install 'use-package)))
+
+;; ... and load 'use-package'
+(require 'use-package)
+
+(use-package server
+  ;; start emacs server if not already running
+  :config
+  (unless (server-running-p) (server-start)))
+
+(use-package  diminish
+  ;; remove clutter from the mode line
+  :ensure t)
+
+(use-package ag
+  ;; interface to the 'ag' tool
+  :ensure t
+  :commands (counsel-ag ag)
+  :bind (:map ag-mode-map
+              ("p" . compilation-previous-error)
+              ("n" . compilation-next-error)
+              ("N" . compilation-next-file)
+              ("P" . compilation-previous-file))
+  :config
+  (setq ag-highlight-search t
+        ag-reuse-buffers t
+        ag-reuse-window t))
+
+(use-package autorevert
+  ;; automatically revert the buffer if the content changed on disk
+  :diminish auto-revert-mode)
+
+(use-package counsel
+  ;; completion functions for ivy
+  :ensure t
+
+  :bind*
+  (("M-x"     . counsel-M-x)
+   ("C-s"     . counsel-grep-or-swiper)
+   ("C-x C-f" . counsel-find-file)
+   ("C-x C-r" . counsel-recentf)
+   ("C-c f"   . counsel-git)
+   ("C-c s"   . counsel-git-grep)
+   ("C-c /"   . counsel-ag))
+
+  :config
+  (setq counsel-find-file-at-point t))
+
+(use-package dired
+  ;; configuration for dired
+  :bind ("C-x C-d" . dired)
+
+  :config
+  (let ((gls "/opt/twitter/bin/gls"))
+    (if (file-exists-p gls)
+        (setq insert-directory-program gls
+              dired-listing-switches "-aBhl --group-directories-first")))
+  (use-package dired-x
+    :init
+    (add-hook 'dired-load-hook (lambda () (load "dired-x")))
+    :config
+    (add-hook 'dired-mode-hook #'dired-omit-mode)
+    (setq dired-omit-verbose nil)
+    (setq dired-omit-files
+          (concat dired-omit-files "\\|^.DS_Store$\\|^.projectile$\\|^.git$"))))
+
+(use-package dockerfile-mode
+  ;; support for dockerfile mode
+  :ensure t)
+
+(use-package lisp-mode
+  ;; simple configuration for various lisp mode
+  :config
+  (add-hook 'emacs-lisp-mode-hook
+            (lambda()
+              (setq mode-name "λ"))))
+
+(use-package eldoc
+  ;; documentation with eldoc
+  :ensure t
+
+  :commands eldoc-mode
+
+  :diminish ""
+
+  :init
+  (add-hook 'emacs-lisp-mode-hook 'eldoc-mode)
+  (add-hook 'lisp-interaction-mode-hook 'eldoc-mode))
+
+(use-package exec-path-from-shell
+  ;; environment fixup for macOS.
+  :ensure t
+
+  :if (and (eq system-type 'darwin) (display-graphic-p))
+
+  :init
+  (setq exec-path-from-shell-check-startup-files nil)
+
+  :config
+  (progn
+    (setq exec-path-from-shell-debug t)
+    (exec-path-from-shell-initialize)))
+
+(use-package flycheck
+  ;; check syntax
+  :ensure t
+
+  :config
+  (progn
+
+    (add-hook 'prog-mode-hook 'flycheck-mode)
+
+    (setq-default flycheck-disabled-checkers '(emacs-lisp-checkdoc))
+    (setq flycheck-highlighting-mode 'lines)
+    (setq flycheck-check-syntax-automatically '(mode-enabled save))))
+
+(use-package flyspell
+  ;; check the spelling
+  :ensure t
+
+  :init
+  (progn
+    (setq ispell-program-name "aspell"
+          ispell-list-command "--list")
+    (add-hook 'text-mode-hook 'flyspell-mode))
+
+  :config
+  (use-package flyspell-popup
+    :ensure t
+    :bind ("C-:" . flyspell-popup-correct)))
+
+(use-package go-mode
+  ;; support for go
+  :mode (("\\.go\\'" . go-mode))
+
+  :ensure t
+
+  :config
+  (progn
+    (when (memq window-system '(mac ns x))
+      (dolist (var '("GOPATH"))
+        (unless (getenv var)
+          (exec-path-from-shell-copy-env var))))
+
+    (use-package go-eldoc
+      :ensure t
+      :config
+      (add-hook 'go-mode-hook 'go-eldoc-setup))
+
+    (use-package gotest
+      :ensure t)
+
+    (use-package go-guru
+      :ensure t)
+
+    (defun fc/my-go-hook ()
+      (set (make-local-variable 'compile-command)
+           "go build -v && go test -v && go vet")
+      (setq-local tab-width 4)
+      (make-variable-buffer-local 'whitespace-style)
+      (setq whitespace-style (delq 'tabs whitespace-style)))
+
+    (add-hook 'before-save-hook 'gofmt-before-save)
+    (add-hook 'go-mode-hook 'fc/my-go-hook)))
+
+(use-package ibuffer
+  ;; configuration for ibuffer
+  :ensure t
+  :defer t
+  :bind ("C-x C-b" . ibuffer)
+  :init
+  (setq-default ibuffer-eliding-string "…")
+  (setq ibuffer-show-empty-filter-groups nil
+        ibuffer-formats '((mark modified read-only " "
+                                (name 30 30 :left :elide)
+                                " "
+                                (size 9 -1 :right)
+                                " "
+                                (mode 16 16 :left :elide)
+                                " " filename-and-process)
+                          (mark " "
+                                (name 16 -1)
+                                " " filename))
+        ibuffer-saved-filter-groups
+        (quote (("default"
+                 ("dired"  (mode . dired-mode))
+                 ("elisp"  (mode . emacs-lisp-mode))
+                 ("emacs"  (or (name . "^\\*.*\\*$") (mode . fundamental-mode)))
+                 ("go"     (mode . go-mode))
+                 ("java"   (mode . java-mode))
+                 ("json"   (mode . json-mode))
+                 ("lisp"   (mode . lisp-mode))
+                 ("magit"  (mode . magit-mode))
+                 ("puppet" (mode . puppet-mode))
+                 ("python" (mode . python-mode))
+                 ("repl"   (name . "repl"))
+                 ("ruby"   (mode . ruby-mode))
+                 ("sh"     (mode . sh-mode))
+                 ("text"   (mode . text-mode))))))
+
+  (add-hook 'ibuffer-mode-hook  ;; organise by filter-groups
+            '(lambda ()
+               (ibuffer-auto-mode 1)
+               (setq mode-name "≣")
+               (ibuffer-switch-to-saved-filter-groups "default"))))
+
+(use-package ivy
+  ;; completion system
+  :diminish (ivy-mode . "")
+
+  :bind ("C-c m" . ivy-switch-project)
+
+  :config
+  (ivy-mode 1)
+  (setq ivy-use-virtual-buffers t
+        ivy-height 10
+        ivy-count-format "(%d/%d) "
+        ivy-initial-inputs-alist nil
+        ivy-use-ignore-default 'always
+        ivy-ignore-buffers '("company-statistics-cache.el" "company-statistics-autoload.el")
+        ivy-re-builders-alist '((swiper . ivy--regex-ignore-order)
+                                (t      . ivy--regex-fuzzy)
+                                (t      . ivy--regex-ignore-order)))
+
+  (defun ivy-switch-project ()
+    (interactive)
+    (ivy-read
+     "Switch to project: "
+     (if (projectile-project-p)
+         (cons (abbreviate-file-name (projectile-project-root))
+               (projectile-relevant-known-projects))
+       projectile-known-projects)
+     :action #'projectile-switch-project-by-name))
+
+  (ivy-set-actions
+   'ivy-switch-project
+   '(("d" dired "Open Dired in project's directory")
+     ("v" counsel-projectile "Open project root in vc-dir or magit")
+     ("c" projectile-compile-project "Compile project")
+     ("r" projectile-remove-known-project "Remove project(s)"))))
+
+(use-package json-mode
+  ;; mode to support json files
+  :ensure t
+
+  :mode "\\.json\\'"
+
+  :config
+  (setq json-reformat:indent-width 2))
+
+(use-package magit
+  ;; interface to git
+  :ensure t
+
+  :mode (("differential-update-comments" . git-commit-mode)
+         ("new-commit"                   . git-commit-mode))
+
+  :bind (("C-x g s" . magit-status)
+         ("C-x g b" . magit-checkout))
+
+  :init
+  (progn
+    (setq magit-completing-read-function 'ivy-completing-read))
+
+  :config
+  (progn
+    (global-git-commit-mode)
+    (use-package git-commit :ensure t :defer t)
+    (add-hook 'magit-mode-hook
+              (lambda()
+                (setq mode-name "⎇")))
+    (add-hook 'magit-log-edit-mode-hook
+              #'(lambda ()
+                  (set-fill-column 72)
+                  (flyspell-mode)))))
+
+(use-package make-mode
+  ;; mode to support Makefile
+  :config
+  (add-hook 'makefile-mode-hook (lambda ()
+                                  (setq-local tab-width 2))))
+
+(use-package markdown-mode
+  ;; mode to support files in the Markdown format
+  :ensure t
+
+  :commands (markdown-mode gfm-mode)
+
+  :mode (("\\.md\\'"       . gfm-mode)
+         ("\\.markdown\\'" . gfm-mode))
+
+  :init (setq markdown-command "pandoc -f markdown_github -c https://goo.gl/OVmlwT --self-contained")
+
+  :config
+  (add-hook 'gfm-mode-hook 'visual-line-mode))
+
+(use-package midnight
+  ;; clean old buffers at midnight
+  :ensure t
+  :config
+  (midnight-mode t))
+
+(use-package org
+  :defer t
+  :init
+  (progn
+    (setq org-startup-indented t)
+    (org-babel-do-load-languages 'org-babel-load-languages
+                                 '(
+                                   (sh . t))))
+  :config
+  (add-hook 'org-mode-hook #'(lambda ()
+                               (visual-line-mode)
+                               (org-indent-mode))))
+
+;; (use-package phabricator
+;;   ;; interface to phabricator
+;;   :load-path (lambda () (expand-file-name  "~/src/phabricator.el/"))
+
+;;   :config
+;;   (setq diffusion-repo-prefix-list '(("source" "source"))))
+
+(use-package projectile
+  ;; library to interact with projects
+  :ensure t
+
+  :diminish ""
+
+  :bind-keymap ("C-c p" . projectile-command-map)
+
+  :init
+  (add-hook 'after-init-hook #'projectile-mode)
+
+  :config
+  (use-package counsel-projectile :ensure t)
+  (setq projectile-switch-project-action 'projectile-dired
+        projectile-enable-caching t
+        projectile-completion-system 'ivy
+        projectile-known-projects-file (expand-file-name "var/projectile-bookmarks.eld" user-emacs-directory)
+        projectile-cache-file (expand-file-name "var/projectile.cache" user-emacs-directory))
+  (add-to-list 'projectile-globally-ignored-files ".DS_Store"))
+
+(use-package python
+  ;; configuration for Python
+  :mode(("\\.aurora$" . python-mode)
+        ("BUILD$"     . python-mode)
+        ("\\.py$"     . python-mode))
+
+  :interpreter ("python" . python-mode)
+
+  :init
+  (setq-default indent-tabs-mode nil)
+
+  :config
+  (setq python-indent-offset 2)
+  (add-hook 'python-mode-hook 'eldoc-mode t))
+
+(use-package recentf
+  ;; configuration for recentf, to interact with recent files
+  :config
+  (setq recentf-save-file (expand-file-name "var/recentf" user-emacs-directory)))
+
+(use-package sh-script
+  ;; configuration to interact with shell scripts
+  :mode ("bashrc" . sh-mode)
+
+  :config
+  (defun set-sh-mode-indent ()
+    (setq sh-basic-offset 2
+          sh-indentation 2))
+  (add-hook 'sh-mode-hook 'set-sh-mode-indent)
+  (add-hook 'after-save-hook 'executable-make-buffer-file-executable-if-script-p))
+
+(use-package swiper
+  ;; install swiper
+  :ensure t)
+
+(use-package tramp
+  ;; configuration for tramp
+  :config
+  (setq tramp-default-method "ssh"
+        tramp-persistency-file-name (expand-file-name "var/tramp" user-emacs-directory)))
+
+(use-package whitespace
+  ;; highlight white spaces
+  :config
+  (setq whitespace-style '(face trailing tabs))
+  (add-hook 'prog-mode-hook 'whitespace-mode))
+
+(use-package yaml-mode
+  ;; mode to work wity YAML files
+  :ensure t
+
+  :init (add-hook 'yaml-mode-hook 'flycheck-mode)
+
+  :mode ("\\.ya?ml\\'" . yaml-mode))