latex: refactor

- Moved backend determination to `config.el`
- Replaced unnecessary backquote construct with simple quotation
- Replaced `pcase` form with only one-arm with `when` or `unless` form
- Refactored function

layers/+lang/latex/config.el

@@ -31,7 +31,7 @@
 ;; ...but AUCTeX runs LaTeX-mode-hook rather than latex-mode-hook, so:
 (add-hook 'LaTeX-mode-hook #'spacemacs//init-jump-handlers-latex-mode)
 
-(defvar latex-backend nil
+(defvar latex-backend (if (configuration-layer/layer-used-p 'lsp) 'lsp 'company-auctex)
   "The backend to use for IDE features.
 Possible values are `lsp' and `company-auctex'.
 If `nil' then 'company-auctex` is the default backend unless `lsp' layer is used")

layers/+lang/latex/funcs.el

@@ -21,50 +21,38 @@
 ;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
-(defun spacemacs//latex-backend ()
-  "Returns selected backend."
-  (if latex-backend
-      latex-backend
-    (cond
-     ((configuration-layer/layer-used-p 'lsp) 'lsp)
-     (t 'company-auctex))))
-
 (defun spacemacs//latex-setup-company ()
   "Conditionally setup company based on backend."
-  (pcase (spacemacs//latex-backend)
+  (pcase latex-backend
     ;; Activate lsp company explicitly to activate
     ;; standard backends as well
-    (`lsp (spacemacs|add-company-backends
+    ('lsp (spacemacs|add-company-backends
             :backends company-capf
             :modes LaTeX-mode))
-    (_ (when (configuration-layer/package-used-p 'company-auctex)
-         (if (configuration-layer/package-used-p 'company-math)
-             (spacemacs|add-company-backends
-               :backends
-               company-math-symbols-unicode
-               company-math-symbols-latex
-               (company-auctex-macros)
-               company-auctex-symbols
-               company-auctex-environments
-               :modes LaTeX-mode)
-           (spacemacs|add-company-backends
-             :backends
-             (company-auctex-macros)
-             company-auctex-symbols
-             company-auctex-environments
-             :modes LaTeX-mode)))
-       (when (configuration-layer/package-used-p 'company-reftex)
-         (spacemacs|add-company-backends
-           :backends
-           company-reftex-labels
-           company-reftex-citations
-           :modes LaTeX-mode)))))
+    ('company-auctex (when (configuration-layer/package-used-p 'company-auctex)
+                       (spacemacs|add-company-backends
+                         :backends (if (configuration-layer/package-usedp 'company-math)
+                                       '(company-math-symbols-unicode
+                                         company-math-symbols-latex
+                                         (company-auctex-macros)
+                                         company-auctex-symbols
+                                         company-auctex-environments)
+                                     '(company-auctex-macros
+                                       company-auctex-symbols
+                                       company-auctex-environments))
+                         :modes LaTeX-mode))
+                     (when (configuration-layer/package-used-p 'company-reftex)
+                      (spacemacs|add-company-backends
+                        :backends
+                        company-reftex-labels
+                        company-reftex-citations
+                        :modes LaTeX-mode)))))
 
 (defun spacemacs//latex-setup-backend ()
   "Conditionally setup latex backend."
-  (pcase (spacemacs//latex-backend)
-    (`lsp (require 'lsp-latex)
-          (lsp))))
+  (when (eq latex-backend 'lsp)
+    (require 'lsp-latex)
+    (lsp)))
 
 (defun latex/build ()
   (interactive)

layers/+lang/latex/packages.el

@@ -99,7 +99,7 @@
           "xff" 'latex/font-sans-serif
           "xfr" 'latex/font-serif)
         (spacemacs/declare-prefix-for-mode mode "mxf" "fonts")
-        (unless (and (eq (spacemacs//latex-backend) 'lsp)
+        (unless (and (eq latex-backend 'lsp)
                      (eq mode 'latex-mode))
           (spacemacs/declare-prefix-for-mode mode "mh" "help")
           (spacemacs/declare-prefix-for-mode mode "mx" "text/fonts")
@@ -154,7 +154,7 @@
         "xfu" 'latex/font-upright)
 
       ;; Rebind latex keys to avoid conflicts with lsp mode
-      (if (eq (spacemacs//latex-backend) 'lsp)
+      (if (eq latex-backend 'lsp)
           (spacemacs/set-leader-keys-for-major-mode 'latex-mode
             "au"   'TeX-command-run-all
             "c"   'latex/build
@@ -192,7 +192,7 @@
   (add-hook 'LaTeX-mode-hook 'turn-on-reftex)
   (setq reftex-plug-into-AUCTeX '(nil nil t t t)
         reftex-use-fonts t)
-  (let ((prefix (if (eq (spacemacs//latex-backend) 'lsp) "R" "r")))
+  (let ((prefix (if (eq latex-backend 'lsp) "R" "r")))
     (spacemacs/declare-prefix-for-mode 'latex-mode (concat "m" prefix) "reftex")
     (spacemacs/set-leader-keys-for-major-mode 'latex-mode
       (concat prefix "c")    'reftex-citation