Add keybindings for hy-mode in python layer

These changes will allow users to evaluate hy code in a repl using an
inferior-lisp process. It requires that users have hy installed via pip
in their local python enviornment.

Add smartparens-mode and documentation

I moved the add-hook for smartparens call to
python/post-init-smartparens. Keybindings were also updated to match
the ones for the Inferior REPL process for Python. Also added some
documentation for required hy pacakge, and the keybindings to
README.org.

layers/+lang/python/README.org

@@ -12,6 +12,7 @@
    - [[#automatic-buffer-formatting-on-save][Automatic buffer formatting on save]]
    - [[#autoflake][autoflake]]
    - [[#pylookup][pylookup]]
+   - [[#hy-mode][Hy-mode]]
  - [[#management-of-python-versions-and-virtual-environments][Management of Python versions and virtual environments]]
    - [[#manage-virtual-environments-with-pyvenv][Manage virtual environments with pyvenv]]
    - [[#manage-multiple-python-versions-with-pyenv][Manage multiple Python versions with pyenv]]
@@ -22,6 +23,7 @@
    - [[#testing][Testing]]
    - [[#refactoring][Refactoring]]
    - [[#live-coding][Live coding]]
+   - [[#hy-repl-process][Hy REPL process]]
    - [[#other-python-commands][Other Python commands]]
  - [[#configuration][Configuration]]
    - [[#fill-column][Fill column]]
@@ -113,6 +115,14 @@ To be able to suppress unused imports easily, install [[https://github.com/myint
 To use =pylookup= on ~SPC m h H~, make sure you update the database first, using
 ~SPC SPC pylookup-update~.
 
+** Hy-mode
+To be able to connect to an inferior lisp repl in =hy-mode=, you need to make sure
+that hy is installed.
+
+#+BEGIN_SRC sh
+  pip install hy
+#+END_SRC
+
 * Management of Python versions and virtual environments
 
 ** Manage virtual environments with pyvenv
@@ -220,12 +230,32 @@ function with a prefix argument, for example ~SPC u SPC m t a~.
 | ~SPC m r i~ | remove unused imports with [[https://github.com/myint/autoflake][autoflake]] |
 
 ** Live coding
+
 Live coding is provided by the [[https://github.com/donkirkby/live-py-plugin][live-py-plugin.]]
 
 | Key Binding | Description         |
 |-------------+---------------------|
 | ~SPC m l~   | Toggle live-py-mode |
 
+** Hy REPL process
+Start a Hy inferior repel process with ~SPC m s i~. If =hy= is
+available in system executable search paths, =hy= will be used to
+launch the shell. You may change your system executable search path
+by activating a virtual enviornment.
+
+Send code to hy REPL commands:
+
+| Key Binding | Description                                               |
+|-------------+-----------------------------------------------------------|
+| ~SPC m s b~ | send buffer and keep code buffer focused                  |
+| ~SPC m s B~ | switch to REPL                                            |
+| ~SPC m s e~ | send sexp in front of the cursor to the REPL              |
+| ~SPC m s f~ | send function to REPL and stay in buffer                  |
+| ~SPC m s F~ | send function to REPL and switch to repl buffer           |
+| ~SPC m s i~ | start inferior hy repl                                    |
+| ~SPC m s r~ | send current region to the REPL and stay in buffer        |
+| ~SPC m s R~ | send current region to the REPL and switch to repl buffer |
+
 ** Other Python commands
 
 | Key Binding | Description                                                                  |

layers/+lang/python/packages.el

@@ -110,7 +110,22 @@
 
 (defun python/init-hy-mode ()
   (use-package hy-mode
-    :defer t))
+    :defer t
+    :init
+    (progn
+      (let ((hy-path (executable-find "hy")))
+        (when hy-path
+          (setq hy-mode-inferior-lisp-command (concat hy-path " --spy"))
+          (spacemacs/set-leader-keys-for-major-mode 'hy-mode
+            "si" 'inferior-lisp
+            "sb" 'lisp-load-file
+            "sB" 'switch-to-lisp
+            "se" 'lisp-eval-last-sexp
+            "sf" 'lisp-eval-defun
+            "sF" 'lisp-eval-defun-and-go
+            "sr" 'lisp-eval-region
+            "sR" 'lisp-eval-region-and-go
+            ))))))
 
 (defun python/init-live-py-mode ()
   (use-package live-py-mode
@@ -163,6 +178,7 @@
     (progn
       (pcase python-auto-set-local-pyenv-version
        (`on-visit
+        (add-hook 'hy-mode-hook 'pyenv-mode-set-local-version)
         (add-hook 'python-mode-hook 'spacemacs//pyenv-mode-set-local-version))
        (`on-project-switch
         (add-hook 'projectile-after-switch-project-hook
@@ -175,10 +191,15 @@
   (use-package pyvenv
     :defer t
     :init
-    (spacemacs/set-leader-keys-for-major-mode 'python-mode
-      "Va" 'pyvenv-activate
-      "Vd" 'pyvenv-deactivate
-      "Vw" 'pyvenv-workon)))
+    (progn
+     (spacemacs/set-leader-keys-for-major-mode 'python-mode
+       "Va" 'pyvenv-activate
+       "Vd" 'pyvenv-deactivate
+       "Vw" 'pyvenv-workon)
+     (spacemacs/set-leader-keys-for-major-mode 'hy-mode
+       "Va" 'pyvenv-activate
+       "Vd" 'pyvenv-deactivate
+       "Vw" 'pyvenv-workon))))
 
 (defun python/init-pylookup ()
   (use-package pylookup
@@ -373,6 +394,7 @@ fix this issue."
 
 (defun python/post-init-smartparens ()
   (add-hook 'inferior-python-mode-hook 'smartparens-mode)
+  (add-hook 'hy-mode-hook 'smartparens-mode)
   (defadvice python-indent-dedent-line-backspace
       (around python/sp-backward-delete-char activate)
     (let ((pythonp (or (not smartparens-strict-mode)