[PATCH 1/2] ob-emacs-lisp: Set `lexical-binding' in edit buffers

[Sebastian Miele <sebastian.miele@gmail.com>]

* lisp/ob-emacs-lisp.el (org-babel-execute:emacs-lisp,
  org-babel-emacs-lisp-lexical): Factor out the conversion of the
  :lexical source block argument to a form that is appropriate for
  `lexical-binding' and the LEXICAL argument to `eval'.

* lisp/ob-emacs-lisp.el (org-babel-edit-prep:emacs-lisp): Set
  `lexical-binding'.

* lisp/ob-emacs-lisp.el (org-babel-default-header-args:emacs-lisp):
  Update docstring.

* etc/ORG-NEWS: Create entry about this under Miscellaneous.
---
 etc/ORG-NEWS          |  6 ++++++
 lisp/ob-emacs-lisp.el | 24 ++++++++++++++++++++----
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/etc/ORG-NEWS b/etc/ORG-NEWS
index 039ad4c69..15af28bfd 100644
--- a/etc/ORG-NEWS
+++ b/etc/ORG-NEWS
@@ -160,6 +160,8 @@ dynamic block in ~org-dynamic-block-alist~.
 *** ~org-table-cell-down~
 *** ~org-table-cell-left~
 *** ~org-table-cell-right~
+*** ~org-babel-emacs-lisp-lexical~
+*** ~org-babel-edit-prep:emacs-lisp~
 ** Removed functions
 *** ~org-babel-set-current-result-hash~
 
@@ -193,6 +195,10 @@ The ~:mkdirp~ header argument used to only work for ~:tangle~ tangle
 files. Now ~:mkdirp~ works for ~:dir~ too. This is more convenient for
 specify default directory and with ~:file~ header argument.
 
+*** ob-emacs-lisp sets ~lexical-binding~ in Org edit buffers
+When editing an Elisp src block, the editing buffer's
+~lexical-binding~ is set according to the src block's =:lexical=
+parameter.
 * Version 9.2
 ** Incompatible changes
 *** Removal of OrgStruct mode mode and radio lists
diff --git a/lisp/ob-emacs-lisp.el b/lisp/ob-emacs-lisp.el
index cd86f4a20..ab7dac879 100644
--- a/lisp/ob-emacs-lisp.el
+++ b/lisp/ob-emacs-lisp.el
@@ -43,7 +43,8 @@
 A value of \"yes\" or t causes source blocks to be eval'd using
 lexical scoping.  It can also be an alist mapping symbols to
 their value.  It is used as the optional LEXICAL argument to
-`eval', which see.")
+`eval', which see.  And it is used as the value for
+`lexical-binding' in buffers created by `org-edit-src-code'.")
 
 (defun org-babel-expand-body:emacs-lisp (body params)
   "Expand BODY according to PARAMS, return the expanded body."
@@ -71,9 +72,7 @@ their value.  It is used as the optional LEXICAL argument to
 				       (member "pp" result-params))
 				   (concat "(pp " body ")")
 				 body))
-			 (if (listp lexical)
-			     lexical
-			   (member lexical '("yes" "t"))))))
+			 (org-babel-emacs-lisp-lexical lexical))))
       (org-babel-result-cond result-params
 	(let ((print-level nil)
               (print-length nil))
@@ -88,6 +87,23 @@ their value.  It is used as the optional LEXICAL argument to
          (org-babel-pick-name (cdr (assq :rowname-names params))
                               (cdr (assq :rownames params))))))))
 
+(defun org-babel-emacs-lisp-lexical (lexical)
+  "Interpret :lexical source block argument.
+Convert LEXICAL into the form appropriate for `lexical-binding'
+and the LEXICAL argument to `eval'."
+  (if (listp lexical)
+      lexical
+    (not (null (member lexical '("yes" "t"))))))
+
+(defun org-babel-edit-prep:emacs-lisp (info)
+  "Set `lexical-binding' in Org edit buffer.
+Set `lexical-binding' in Org edit buffer according to the
+corresponding :lexical source block argument."
+  (setq lexical-binding
+        (org-babel-emacs-lisp-lexical
+         (org-babel-read
+          (cdr (assq :lexical (nth 2 info)))))))
+
 (org-babel-make-language-alias "elisp" "emacs-lisp")
 
 (provide 'ob-emacs-lisp)
-- 
2.21.0