* Packaging
** Package.el
[[http://wikemacs.org/wiki/Package.el][Package.el]] is the built-in package manager in Emacs. This is where the fun begins.
#+BEGIN_SRC emacs-lisp
  (require 'package)
  (setq package-archives
        '(("gnu"          . "https://elpa.gnu.org/packages/")
          ("melpa"        . "https://melpa.org/packages/")
          ("melpa-stable" . "https://stable.melpa.org/packages/")
          ("marmalade"    . "https://marmalade-repo.org/packages/")
          ("org"          . "https://orgmode.org/elpa/")))
  (setq package-enable-at-startup nil)
  (package-initialize)
#+END_SRC
** use-package
[[https://github.com/jwiegley/use-package][use-package]] is a nifty macro that interfaces with =Package.el=, keeping package-specific
configuration all in once place. It's pretty much the basis of this entire config.
#+BEGIN_SRC emacs-lisp
  (unless (package-installed-p 'use-package)
    (package-refresh-contents)
    (package-install 'use-package))

  (eval-when-compile
    (require 'use-package))

  (setq use-package-compute-statistics t)
  (setq use-package-always-ensure t)
  (setq use-package-always-pin "melpa")
  (setq use-package-verbose t)
#+END_SRC
*** Custom Keywords
A few useful =:keyword= macros that extend the vanilla =use-package= functionality.
**** :company
#+BEGIN_SRC emacs-lisp
  (defun use-package-company-normalize (name keyword args)
    "Normalize the KEYWORD with NAME :company with arguments ARGS into a list of pairs for the handler."
    (use-package-as-one (symbol-name keyword) args
      (lambda (label arg)
        (unless (or (consp arg) (use-package-non-nil-symbolp arg))
          (use-package-error
            (concat
              label
              "<symbol> or "
              "(<symbol or list of symbols> . <symbol or function>) or "
              "a list of these")))
        (use-package-normalize-pairs
          (lambda (k)
            (or (use-package-non-nil-symbolp k)
                (and (consp k)
                     (not (cdr (last k)))
                     (seq-every-p 'use-package-non-nil-symbolp k))))
          #'use-package-recognize-function
          name label arg))))

  ;;;###autoload
  (defun use-package-company-handler (name _keyword args rest state)
    "Generate a function and hook from each pair in NAME ARGS for the keyword with NAME :company, appending the forms to the ‘use-package’ declaration specified by REST and STATE."
    (use-package-concat
     (use-package-process-keywords name rest state)
     (mapcan
      (lambda (def)
        (let ((modes (car def))
              (backend (cdr def))
              (fun (intern (concat "use-package-company-add-" (symbol-name (cdr def))))))
          (when backend
            (append
             `((defun ,fun ()
                 (setq-local company-backends
                             (append company-backends '(,backend)))))
             (mapcar
              (lambda (mode)
                `(add-hook
                  ',(derived-mode-hook-name mode)
                  #',fun))
              (if (use-package-non-nil-symbolp modes) (list modes) modes))))))
      (use-package-normalize-commands args))))

  (defalias 'use-package-normalize/:company 'use-package-company-normalize)
  (defalias 'use-package-handler/:company 'use-package-company-handler)
  (defalias 'use-package-autoloads/:company 'use-package-autoloads-mode)

  (setq use-package-keywords
    (let ((idx (+ 1 (cl-position :hook use-package-keywords))))
      (append
        (seq-subseq use-package-keywords 0 idx)
        (list :company)
        (nthcdr idx use-package-keywords))))
#+END_SRC
* Keybinds
** which-key
[[https://github.com/justbur/emacs-which-key][which-key]] displays a popup in the minibuffer that shows 
keybindings following incomplete commands.
#+BEGIN_SRC emacs-lisp
  (use-package which-key
    :diminish
    :config
    (which-key-mode))
#+END_SRC
** General
[[https://github.com/noctuid/general.el][General]] is an excellent keybind manager that adds *tons* of useful macros.
Also set up a leader key and prefixes, like =\= in Vim.
#+BEGIN_SRC emacs-lisp
  (use-package general
    :config
    (general-create-definer jf-leader-def
      :keymaps 'override
      :states '(normal insert emacs)
      :prefix "SPC"
      :non-normal-prefix "M-SPC")

    (defun jf-create-wk-prefix (desc)
      "Helper for creating which-key prefix descriptions.
  Bind to a key with general to make which-key show DESC
  as the prefix's description"
      `(:ignore t :wk ,desc))

    (defmacro jf-create-definers (definitions)
      "A wrapper for general-create-definer.
    For every pair in DEFINITIONS, creates a leader
    with name jf-NAME-def and keybind SPC KEY or M-SPC KEY in normal mode."
      `(progn
         ,@(mapcan
            (lambda (def)
              (let ((key  (car def))
                    (name (cdr def)))
                `((general-create-definer ,(intern (concat "jf-" name "-def"))
                    :keymaps 'override
                    :states '(normal insert emacs)
                    :prefix ,(concat "SPC " key)
                    :non-normal-prefix ,(concat "M-SPC " key))
                  (jf-leader-def ,key ',(jf-create-wk-prefix name)))))
            definitions)))

    (jf-create-definers
     (("a" . "apps")
      ("b" . "buffers")
      ("f" . "files")
      ("g" . "git")
      ("h" . "help")
      ("m" . "major")
      ("o" . "org")
      ("p" . "projects")
      ("w" . "windows"))))
#+END_SRC
* Vim Emulation
** Evil
[[https://github.com/emacs-evil/evil][Evil]] is pretty much the entirety of Vim in Emacs.
#+BEGIN_SRC emacs-lisp
  (use-package evil
    :diminish undo-tree-mode

    :init
    (setq evil-want-integration t)
    (setq evil-want-keybinding nil)

    (defun jf-window-split ()
      (interactive)
      (evil-window-split)
      (evil-window-down 1))
    (defun jf-window-vsplit ()
      (interactive)
      (evil-window-vsplit)
      (evil-window-right 1))

    :config
    (evil-mode t)

    (jf-windows-def
     "-" #'jf-window-split
     "=" #'jf-window-vsplit
     "b" #'balance-windows
     "H" #'evil-window-far-left
     "J" #'evil-window-bottom
     "K" #'evil-window-top
     "L" #'evil-window-far-right
     "h" #'evil-window-left
     "j" #'evil-window-right
     "k" #'evil-window-down
     "l" #'evil-window-right
     "o" #'other-frame))
#+END_SRC
** Evil Collection
[[https://github.com/emacs-evil/evil-collection][Evil Collection]] adds Evil bindings for all the parts of Emacs that Evil
doesn't cover properly by default.
#+BEGIN_SRC emacs-lisp
  (use-package evil-collection
    :after evil
    :config
    (evil-collection-init
     '(calendar
       cmake-mode
       company
       custom
       debug
       dired
       doc-view
       elisp-mode
       elisp-refs
       eshell
       eval-sexp-fu
       flycheck
       flymake
       grep
       help
       ibuffer
       image
       image-dired
       info
       ivy
       js2-mode
       log-view
       man
       neotree
       python
       racer
       realgud
       which-key)))
#+END_SRC
** Evil Extensions
*** Avy
An enhanced version of =f= in Vim.
#+BEGIN_SRC emacs-lisp
  (use-package avy
    :general
    (:keymaps 'override
      :states 'normal
      "C-f" 'avy-goto-char-in-line
      "C-F" 'avy-goto-char))
#+END_SRC
*** evil-surround
Use =S= and a delimiter to surround in visual mode.
#+BEGIN_SRC emacs-lisp
(use-package evil-surround
    :after evil
    :diminish
    :config
    (global-evil-surround-mode 1))
#+END_SRC
* Emacs
** Defaults
*** Configuration Editing
Add functions for editing and reloading the Emacs config files.
#+BEGIN_SRC emacs-lisp
  (defun jf-edit-config ()
    (interactive)
    (find-file jf-config-file))

  (defun jf-edit-init ()
    (interactive)
    (find-file jf-init-file))

  (defun jf-reload-config ()
    (interactive)
    (org-babel-load-file jf-config-file))

  (jf-files-def
    "e"  (jf-create-wk-prefix "emacs files")
    "ec" #'jf-edit-config
    "ei" #'jf-edit-init
    "er" #'jf-reload-config)
#+END_SRC
*** Add to Load Path
Create and add a folder to the load path for local lisp files.
The folder itself and all descendants will be added to the path.
These packages will take precedence over other libraries with the same name.
#+BEGIN_SRC emacs-lisp
  (unless (file-exists-p jf-load-path)
    (make-directory jf-load-path))

  (let ((default-directory jf-load-path))
    (setq load-path
          (append
           (let ((load-path (copy-sequence load-path)))
             (append
              (copy-sequence (normal-top-level-add-to-load-path '(".")))
              (normal-top-level-add-subdirs-to-load-path)))
           load-path)))
#+END_SRC
*** File Not Found Functions
Offer to create parent folders when a file is opened
Offer to create nonexistant parent directories.
#+BEGIN_SRC emacs-lisp
  (defun jf-create-nonexistant-directories ()
    (let ((parent-directory (file-name-directory buffer-file-name)))
      (when (and (not (file-exists-p parent-directory))
                (y-or-n-p (format "Directory `%s' does not exist. Create it?" parent-directory)))
        (make-directory parent-directory t)))) ; last argument specifies to behave like `mkdir -p'

  (add-to-list 'find-file-not-found-functions #'jf-create-nonexistant-directories)
#+END_SRC
*** Customize Location
Make changes in =M-x customize= go somewhere other than being schlunked into =init.el=.
#+BEGIN_SRC emacs-lisp
  (setq custom-file (concat user-emacs-directory "_customize.el"))
  (load custom-file t)
#+END_SRC
*** Disable Bell
Shut up, emacs.
#+BEGIN_SRC emacs-lisp
  (setq ring-bell-function #'ignore)
#+END_SRC
*** Shorter Prompts
Make =yes-or-no= prompts ask for =y-or-n= instead. Saves loads of time™.
#+BEGIN_SRC emacs-lisp
  (defalias 'yes-or-no-p #'y-or-n-p)
#+END_SRC
*** Move Backup Files
By default, emacs gunks up every folder with =file~= backups 
and =#file#= lockfiles. Schlunk them all in =/tmp= instead.
#+BEGIN_SRC emacs-lisp
  (setq backup-directory-alist
        `((".*" . ,temporary-file-directory)))
  (setq auto-save-file-name-transforms
        `((".*" ,temporary-file-directory t)))
#+END_SRC
*** Nicer Scrolling
Keep the cursor away from the edges when scrolling,
rather than hitting the bottom and scrolling a metric
boatload off the screen.
#+BEGIN_SRC emacs-lisp
  (require 'smooth-scrolling)
#+END_SRC

*** Secure auth-source
GPG encrypt stored auth tokens from [[https://www.gnu.org/software/emacs/manual/html_mono/auth.html][auth-source]] instead of storing them in plaintext.
#+BEGIN_SRC emacs-lisp
  (setq auth-sources '("~/.emacs.d/authinfo.gpg"))
#+END_SRC
*** Use UTF-8
Pleeeease default to UTF-8, Emacs.
#+BEGIN_SRC emacs-lisp
  (setq locale-coding-system 'utf-8)
  (set-terminal-coding-system 'utf-8)
  (set-keyboard-coding-system 'utf-8)
  (set-selection-coding-system 'utf-8)
  (prefer-coding-system 'utf-8)
#+END_SRC
*** Trash when Deleting
Don't permanently delete stuff unless asked.
#+BEGIN_SRC emacs-lisp
  (setq delete-by-moving-to-trash t)
#+END_SRC
*** Open Compressed Files
...automatically.
#+BEGIN_SRC emacs-lisp
  (setq auto-compression-mode t)
#+END_SRC
*** Save Minibuffer History
#+BEGIN_SRC emacs-lisp
  (savehist-mode 1)
  (setq history-length 1000)
#+END_SRC
*** Double Spaces
Why sentences would need double spaces to end I do not know.
#+BEGIN_SRC emacs-lisp
  (set-default 'sentence-end-double-space nil)
#+END_SRC
*** Eval Print Level
Print more stuff when running =C-x C-e= or =(eval-last-sexp)=
#+BEGIN_SRC emacs-lisp
  (setq eval-expression-print-level 100)
#+END_SRC
** UI
*** Font
Engage a nice coding font.
#+BEGIN_SRC emacs-lisp
  (add-to-list 'default-frame-alist '(font . "Fira Code 12"))
  (set-face-attribute 'default t :font "Fira Code 12")
#+END_SRC
*** Menu Bar
Disable the useless cruft at the top of the screen.
#+BEGIN_SRC emacs-lisp
  (menu-bar-mode -1)
  (tool-bar-mode -1)
  (scroll-bar-mode -1)
#+END_SRC
*** Modeline
**** Diminish
Adds support for =:diminish= in use-package declarations, which hides a mode from the modeline.
#+BEGIN_SRC emacs-lisp
(use-package diminish)
#+END_SRC
**** Column Number
Show line and column numbers in the modeline.
#+BEGIN_SRC emacs-lisp
(setq line-number-mode t)
(setq column-number-mode t)
#+END_SRC
*** Line Numbers
Use the default emacs relative line numbers, but switch to absolute lines when in insert mode.
#+BEGIN_SRC emacs-lisp
  (use-package nlinum-relative
    :config
    (nlinum-relative-setup-evil)
    :hook (prog-mode . nlinum-relative-mode))
#+END_SRC

*** Show Matching Parens
Shows matching parenthesis  
#+BEGIN_SRC emacs-lisp
(require 'paren)
(setq show-paren-delay 0)
(show-paren-mode)
#+END_SRC
*** Dashboard
Show a cool custom dashboard buffer on startup.
#+BEGIN_SRC emacs-lisp
  (use-package dashboard
    :diminish page-break-lines-mode
    :config
    (dashboard-setup-startup-hook)
    (setq initial-buffer-choice (lambda () (get-buffer "*dashboard*")))

    :custom
    (dashboard-startup-banner 'logo)
    (dashboard-banner-logo-title "Welcome to Electronic Macs")
    (dashboard-items
     '((recents . 5)
       (agenda)
       (bookmarks . 5)
       (registers . 5))))
#+END_SRC
** Themes
*** pywal
Fancy dynamic color scheme generation from desktop wallpapers.
Requires additional setup on the machine itself.
#+BEGIN_SRC emacs-lisp
  (defvar jf-theme-pywal-path "~/.cache/wal/colors.el" "Path to the colorscheme generated by pywal.")

  (defun jf-theme-pywal ()
    (load-file jf-theme-pywal-path))

  (when (eq 'jf-theme 'jf-theme-pywal)
    (require 'filenotify)
    (file-notify-add-watch jf-theme-pywal-path '(change) #'jf-theme-pywal))
#+END_SRC
*** spacemacs
This theme is pretty fancy and has lots of supported modes.
#+BEGIN_SRC emacs-lisp
  (unless (package-installed-p 'spacemacs-theme)
    (package-install 'spacemacs-theme))

  (defun jf-theme-spacemacs ()
    (load-theme 'spacemacs-dark))
#+END_SRC
*** Transparency
Sets the window's transparency, to better admire choice wallpapers.
The first number in the alpha section applies when the window is
active, the second when it's inactive.
#+BEGIN_SRC emacs-lisp
(set-frame-parameter (selected-frame) 'alpha 85)
(add-to-list 'default-frame-alist '(alpha . 85))
#+END_SRC
    
*** Helpers
#+BEGIN_SRC emacs-lisp
  (defvar jf-theme #'jf-theme-pywal "Theme function to call.")

  (defun jf-apply-theme ()
    "Apply the current theme as set by jf-theme."
    (funcall jf-theme))

  (jf-apply-theme)
#+END_SRC
* Communication
* Web
* Tools
* Programming
** Formatting
*** Indentation
Set some *sane* defaults
#+BEGIN_SRC emacs-lisp
(setq foltz-tab-width 4)
(setq-default python-indent-offset foltz-tab-width)
(setq-default evil-shift-width foltz-tab-width)
(setq-default c-basic-offset foltz-tab-width)
; Disable annoying electric indent of previous lines
(setq-default electric-indent-inhibit t)
; Eat the whole tab when I press backspace
(setq backward-delete-char-untabify-method 'hungry)
#+END_SRC
Define some *useful* helper functions
#+BEGIN_SRC emacs-lisp
(defun foltz-indent-tabs ()
  (interactive)
  (setq tab-width foltz-tab-width)
  (local-set-key (kbd "") 'tab'to-tab-stop)
  (setq indent-tabs-mode t))

(defun foltz-indent-spaces (num-spaces)
  (interactive)
  (setq tab-width num-spaces)
  (setq indent-tabs-mode nil))
(defun foltz-indent-2-spaces ()
  (foltz-indent-spaces 2))
(defun foltz-indent-4-spaces ()
  (foltz-indent-spaces 4))
(defun foltz-indent-8-spaces ()
  (foltz-indent-spaces 8))

(foltz-indent-4-spaces)

(setq whitespace-style '(face tabs tab-mark trailing))
(custom-set-faces
   '(whitespace-tab ((t (:foreground "#636363")))))

(setq whitespace-display-mappings
   '((tab-mark 9 [124 9] [92 9])))

(add-hook 'prog-mode-hook #'whitespace-mode)
#+END_SRC
*** Smart Parentheses
smartparens handles parens for languages that aren't lispy,
and paredit handles the rest.
Keybinds in =M-x sp-cheat-sheet=.
#+BEGIN_SRC emacs-lisp
(use-package paredit
    :diminish
    :commands enable-paredit-mode)
     
(use-package smartparens
    :diminish
    :commands smartparens-strict-mode
    :config
    (require 'smartparens-config))

(use-package evil-smartparens
    :hook (smartparens-enabled . evil-smartparens-mode))
#+END_SRC
*** Smart Parentheses Modes
Picks a suitable parenthesis editing mode for the 
current major mode when entering any prog-mode.
#+BEGIN_SRC emacs-lisp
(defun foltz-paren-mode ()
    (if (member major-mode 
          '(emacs-lisp-mode
            lisp-mode
            lisp-interaction-mode
            scheme-mode))
        (enable-paredit-mode)
        (smartparens-strict-mode)))

(add-hook 'prog-mode-hook #'foltz-paren-mode)
#+END_SRC
*** ws-butler
Unobtrusively cleans up whitespace before EOLs 
as you edit, stopping the noisy commits generated 
from blanket trimming entire files.
#+BEGIN_SRC emacs-lisp
(use-package ws-butler
    :hook (prog-mode . ws-butler-mode))
#+END_SRC
*** pretty-mode
[[https://github.com/pretty-mode/pretty-mode][Redisplay parts of the Emacs buffer as pretty symbols.]]
#+BEGIN_SRC emacs-lisp
(use-package pretty-mode
    :hook (prog-mode . pretty-mode)
    :config
    (pretty-deactivate-groups
        '(:equality :sub-and-superscripts))
    (pretty-activate-groups
        '(:greek :arithmetic-nary
          :ordering :ordering-double :ordering-triple
          :arrows :arrows-twoheaded :punctuation :logic :sets)))
#+END_SRC

*** prettify-symbols-mode
Built into emacs since 24.1
#+BEGIN_SRC emacs-lisp
(add-hook 'python-mode-hook 'prettify-symbols-mode)
(add-hook 'python-mode-hook (lambda ()
    (mapc (lambda (pair) (push pair prettify-symbols-alist))
        '(;; Syntax
         ("in" .       #x2208)
         ("not in" .   #x2209)
         ("return" .   #x27fc)
         ("yield" .    #x27fb)
         ("for" .      #x2200)
         ;; Base Types
         ("int" .      #x2124)
         ("float" .    #x211d)
         ("str" .      #x1d54a)
         ("True" .     #x1d54b)
         ("False" .    #x1d53d)))))
#+END_SRC

*** Column 80 Highlight
Add a hotkey for highlighting column 80
and activate it in =prog-mode=
#+BEGIN_SRC emacs-lisp
(use-package fill-column-indicator
    :init
    (setq fci-rule-use-dashes t)
    (setq fci-rule-column 80)
    :general)
#+END_SRC

** Checkers
*** Flycheck
Flycheck does syntax highlighting in a few languages
#+BEGIN_SRC emacs-lisp
(use-package flycheck
    :hook (prog-mode . flycheck-mode))
#+END_SRC
** Completion
*** Company
company auto-completes stuff in the buffer,
company-quickhelp shows documentation popups
when idling on a completion candidate.
#+BEGIN_SRC emacs-lisp
(use-package company
    :defer t
    :hook ((prog-mode cdlatex-mode) . company-mode)
    :general
    (:keymaps 'company-active-map
     "C-SPC" 'company-abort)
    :custom
    (company-maximum-prefix-length 2)
    (company-idle-delay 0.2 "Decrease idle delay"))

(use-package company-quickhelp
  :after company
  :hook (company-mode . company-quickhelp-mode))
#+END_SRC
** Snippets
Yasnippet adds support for custom snippets
#+BEGIN_SRC emacs-lisp
(use-package yasnippet
    :commands yas-minor-mode
    :hook (prog-mode . yas-minor-mode)
    :custom
    (yas-snippet-dirs
      '("~/.emacs.d/snippets"
        "~/.emacs.d/elpa/yasnippet-snippets-0.6/snippets")))
;;;(use-package yasnippet-snippets)
#+END_SRC

** Debugging
*** Realgud
[[https://github.com/realgud/realgud][Realgud]] is a modular frontend for many debuggers
#+BEGIN_SRC emacs-lisp
(use-package realgud
    :commands 
    (realgud:gdb 
     realgud:lldb 
     realgud:node-inspect 
     realgud:pdb 
     realgud:trepan3k))
#+END_SRC
*** RMSBolt
#+BEGIN_SRC emacs-lisp
(use-package rmsbolt
    :commands rmsbolt-mode)
#+END_SRC
** Git
*** magit
It's magic git!
Keybinds [[https://github.com/emacs-evil/evil-magit][here]]
#+BEGIN_SRC emacs-lisp
  (use-package magit
      :general)
#+END_SRC
It's *evil* magic git!
#+BEGIN_SRC emacs-lisp
(use-package evil-magit
  :after (evil magit))
#+END_SRC
*** forge
Magic GitHub facilities for git forges such as GitHub and GitLab!
#+BEGIN_SRC emacs-lisp
  (use-package forge
    :after magit
    :init
    (setq foltz-forge-hosts
      '(("git.lcsr.rutgers.edu" "git.lcsr.rutgers.edu/api/v4" "git.lcsr.rutgers.edu" forge-gitlab-repository)))
    :config
    (setq forge-alist (append forge-alist foltz-forge-hosts)))
#+END_SRC
** Projects
Projectile provides project-level features like
make shortcuts and file switching
#+BEGIN_SRC emacs-lisp
(use-package projectile
    :init
    (defun foltz-projectile-neotree () "Open NeoTree in the project root"
        (interactive)
        (let
            ((project-dir (projectile-project-root))
             (file-name   (buffer-file-name)))
        (neotree-toggle)
        (if project-dir
            (if (neo-global--window-exists-p)
                (progn
                    (neotree-dir project-dir)
                    (neotree-find file-name))))))

    (defun foltz-projectile-discover-projects (directory) "Add projects in dir to projectile cache"
        (interactive
            (list (read-directory-name "Starting directory: ")))
        (let ((subdirs (directory-files directory t)))
            (mapcar (lambda (dir)
                (when 
                    (and 
                        (file-directory-p dir)
                        (not (member (file-name-nondirectory dir) '(".." "."))))
                    (let ((default-directory dir) (projectile-cached-project-root dir))
                        (when (projectile-project-p)
                            (projectile-add-known-project (projectile-project-root))))))
                subdirs)))

    :config
    (projectile-mode 1)
    (foltz-projectile-discover-projects "~/Documents/dev")
    :general
    (:keymaps 'projectile-command-map
     "t" 'foltz-projectile-neotree)
    :custom
    (projectile-completion-system 'ivy)
    (projectile-project-search-path '("~/Documents/dev")))
#+END_SRC
** Tools
** Languages
*** Fish
Beter editing of scripts for the fish shell
#+BEGIN_SRC emacs-lisp
(use-package fish-mode
    :mode "\\.fish\\'")
#+END_SRC
*** Markdown
#+BEGIN_SRC emacs-lisp
(use-package markdown-mode
    :mode "\\.md\\'")
#+END_SRC

*** Python
Jedi for autocompletion sources
#+BEGIN_SRC emacs-lisp
(use-package company-jedi
    :company python-mode)
#+END_SRC

*** Javascript
[[https://github.com/mooz/js2-mode][js2-mode]] improves the default js mode. Keybindings in [[https://github.com/emacs-evil/evil-collection/blob/master/evil-collection-js2-mode.el][this file]].
#+BEGIN_SRC emacs-lisp
(use-package js2-mode
    :mode "\\.js\\'"
    :interpreter "node")
#+END_SRC

*** Web-dev
Web-mode should give everything you need for a web-dev major mode.
Company integration is done with company-web

#+BEGIN_SRC emacs-lisp
(use-package web-mode
    :mode ("\\.html\\'"
           "\\.php\\'"
           "\\.blade\\.")
    :custom
    (web-mode-code-indent-offset 4)
    (web-mode-indent-style 4))

(use-package company-web
    :company web-mode)
#+END_SRC

*** JSON
Just an enhanced json mode
#+BEGIN_SRC emacs-lisp
(use-package json-mode
    :mode "\\.json\\'")
#+END_SRC

*** YAML
Enhanced yaml mode
#+BEGIN_SRC emacs-lisp
(use-package yaml-mode
    :mode "\\.yaml\\'")
#+END_SRC

*** Arch PKGBUILD
For editing PKGBUILD files
#+BEGIN_SRC emacs-lisp
(use-package pkgbuild-mode
    :mode ".*PKGBUILD\\'")
#+END_SRC

*** LaTeX
**** AUCTeX
AUCTeX is a major mode for editing tex,
CDLaTeX adds some minor niceities to it.
company-auctex for completion.
#+BEGIN_SRC emacs-lisp
(use-package tex
    :defer t
    :ensure auctex
    :general
    :custom
    (TeX-auto-save t))

(use-package company-auctex
    :company LaTeX-mode)

(use-package company-math
    :company ((TeX-mode . company-math-symbols-latex)
              (TeX-mode . company-math-symbols-unicode)
              (TeX-mode . company-latex-commands)))
#+END_SRC
**** cdlatex
***** Environment
#+BEGIN_SRC emacs-lisp
(setq foltz-cdlatex-envs nil)
#+END_SRC
***** Commands
#+BEGIN_SRC emacs-lisp
(setq foltz-cdlatex-commands nil)
#+END_SRC
***** Math Symbols
#+BEGIN_SRC emacs-lisp
(setq foltz-cdlatex-symbols
  '((?I ("\\infty"))))
#+END_SRC
***** cdlatex
cdlatex adds better TeX-specific template expansions and other niceties.
#+BEGIN_SRC emacs-lisp
(use-package cdlatex
    :hook (LaTeX-mode . cdlatex-mode)
    :custom
    (cdlatex-env-alist foltz-cdlatex-envs)
    (cdlatex-command-alist foltz-cdlatex-commands)
    (cdlatex-math-symbol-alist foltz-cdlatex-symbols))
#+END_SRC
*** Rust
#+BEGIN_SRC emacs-lisp
(use-package rust-mode
    :mode "\\.rs\\'"
    :general)

(use-package flycheck-rust
    :hook (rust-mode . flycheck-rust-setup))

(use-package racer
    :hook ((rust-mode . racer-mode)
           (rust-mode . eldoc-mode))
    :custom
    (racer-cmd "~/.cargo/bin/racer")
    (racer-rust-src-path "~/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/src"))

(use-package cargo
    :hook (rust-mode . cargo-minor-mode)
    :general)
#+END_SRC
*** C/C++
**** Irony
Irony handles enhanced C/C++ operations powered by clang
company-irony for company integration
#+BEGIN_SRC emacs-lisp
(use-package irony
    :after counsel
    :hook ((c++-mode   . irony-mode)
           (c-mode     . irony-mode)
           (irony-mode . irony-cdb-autosetup-compile-options)))

(use-package company-irony
    :company irony-mode)

(use-package company-irony-c-headers
    :company irony-mode)

(use-package flycheck-irony
    :hook (irony-mode . flycheck-irony-setup))
#+END_SRC
**** Hotkeys
#+BEGIN_SRC emacs-lisp
#+END_SRC