[WiP] Added a prog mode to flycheck-languagetool

[mattiasdrp]

This is done by filtering out the errors that don't point to a place that has not a comment, a string or a doc face. The checker is added as the next checker of the main flycheck checker for the current mode

I still have some issues as to when the function flycheck-languagetool-flycheck-enable has to be used

In my current setup what I did is:

  (use-package flycheck-languagetool
    :load-path "lisp/flycheck-languagetool/"
    ;; :custom ((flycheck-languagetool-active-modes
    ;;           '(text-mode latex-mode org-mode markdown-mode message-mode prog-mode)))
    :hook ((text-mode . flycheck-languagetool-setup)
           (lsp-mode . (lambda () (lsp-diagnostics-mode 1)
                         (require 'flycheck-languagetool)
                         (flycheck-languagetool-flycheck-enable))))
    ;; :ensure-system-package
    ;;   ("LanguageTool-5.9-stable/languagetool-commandline.jar" . "curl -L https://raw.githubusercontent.com/languagetool-org/languagetool/master/install.sh | sudo bash -a")
    :init
    (setq flycheck-languagetool-server-jar (expand-file-name "~/.emacs.d/LanguageTool-5.9-stable/languagetool-server.jar"))
    )

But this is not really good.

The issue is that if languagetool is added as a checker before the main-mode finished loading, it's not added as a next checker for the main one and the function needs to be called again.

Fixes #22

If this seems good for you, I think an improvement would be to define a predicate function

This would allow to define different predicates for different modes (prog-mode don't have the same predicates as org-mode or markdown-mode for example)

[jcs090218]

Few comments:

1. Maybe we should get rid of the (require 'flycheck-mode) here since we already have it at the very top.
2. I don't think enabling flycheck-mode and such a setup is a good idea, we usually let the user decide weather the flycheck-mode is enabled or not. Of course, we can still expose a function for that but we need to clarify so the user don't get confuse between flycheck-languagetool-flycheck-enable and flycheck-languagetool-setup. (Might need to update the README for this)
3. Should the variable flycheck-languagetool--text-mode be defvar-local? Anyway, I think it's better if we reuse flycheck-languagetool-setup for prog-mode as well. For example,

(defcustom flycheck-languagetool-prog-modes
  '(actionscript-mode haxe-mode nxml-mode yaml-mode)
  "List of extra `prog-mode'.")

(defun flycheck-languagetool-prog-mode-p ()
  "Return non-nil if current buffer is programming mode."
  (or (derived-mode-p 'prog-mode)
      (memq major-mode flycheck-languagetool-prog-modes)))

then

(defun flycheck-languagetool-setup ()
  "Setup flycheck-package."
  (interactive)
  (when (flycheck-languagetool-prog-mode-p)
    (flycheck-languagetool-flycheck-add-mode major-mode)
    (flycheck-add-next-checker (flycheck-get-checker-for-buffer) 'languagetool))
  ;; do it whenever this is programming mode or not
  (add-to-list 'flycheck-checkers 'languagetool))

;;;###autoload
(defun flycheck-languagetool-flycheck-enable ()
  "Enable flycheck languagetool integration for the current buffer.
This adds languagetool as the next checker of the main checker
of the current buffer"
  (interactive)
  (flycheck-mode 1)
  (flycheck-stop)
  (setq flycheck-languagetool--text-mode nil)  ; still not quite sure what this does
  (flycheck-languagetool-setup))  ; reuse it

This way, user wouldn't need to do extra configuration for prog-mode support. BTW, above code is an example, so please change it to make it work! ;)

[mattiasdrp]

Thanks for the review! This is clearly a work in progress, I needed to do something minimal that worked to start the process of iterating over it. I'll look into your suggestions :-)