Hi Ihor,
Modifications made and split into two patches. Let me know if any
remaining issues.
Thanks
Matt
>From fdc6e103932c68b450c72d44d062b4746ec2202c Mon Sep 17 00:00:00 2001
From: Matt Huszagh <huszaghm...@gmail.com>
Date: Mon, 27 Jun 2022 20:41:02 -0700
Subject: [PATCH 1/2] ob-core.el: Fix behavior of lambda default header arg
vars
* lisp/ob-core.el: Permit multiple :var default header arguments when
using closures.
---
lisp/ob-core.el | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/lisp/ob-core.el b/lisp/ob-core.el
index 7a9467b0e..80086f12c 100644
--- a/lisp/ob-core.el
+++ b/lisp/ob-core.el
@@ -2718,6 +2718,11 @@ parameters when merging lists."
(pcase pair
(`(:var . ,value)
(let ((name (cond
+ ;; Default header arguments can accept lambda
+ ;; functions. We uniquely identify the var
+ ;; according to the full string contents of
+ ;; the lambda function.
+ ((functionp value) value)
((listp value) (car value))
((string-match "^\\([^= \f\t\n\r\v]+\\)[ \t]*=" value)
(intern (match-string 1 value)))
--
2.31.1
>From 7af7ad3990410ca388c841e045ec66ce694b404a Mon Sep 17 00:00:00 2001
From: Matt Huszagh <huszaghm...@gmail.com>
Date: Mon, 27 Jun 2022 20:42:27 -0700
Subject: [PATCH 2/2] ob-core.el: Improve org-babel-default-header-args
docstring
* lisp/ob-core.el: Provide example illustrating one benefit of using
closures as default header arguments. Additionally, explain how to
provide the same type of header argument multiple times in the default
alist.
---
lisp/ob-core.el | 25 ++++++++++++++++++-------
1 file changed, 18 insertions(+), 7 deletions(-)
diff --git a/lisp/ob-core.el b/lisp/ob-core.el
index 80086f12c..6c3c79126 100644
--- a/lisp/ob-core.el
+++ b/lisp/ob-core.el
@@ -478,12 +478,14 @@ For the format of SAFE-LIST, see `org-babel-safe-header-args'."
This is a list in which each element is an alist. Each key
corresponds to a header argument, and each value to that header's
value. The value can either be a string or a closure that
-evaluates to a string. The closure is evaluated when the source
-block is being evaluated (e.g. during execution or export), with
-point at the source block. It is not possible to use an
-arbitrary function symbol (e.g. 'some-func), since org uses
-lexical binding. To achieve the same functionality, call the
-function within a closure (e.g. (lambda () (some-func))).
+evaluates to a string.
+
+A closure is evaluated when the source block is being
+evaluated (e.g. during execution or export), with point at the
+source block. It is not possible to use an arbitrary function
+symbol (e.g. 'some-func), since org uses lexical binding. To
+achieve the same functionality, call the function within a
+closure (e.g. (lambda () (some-func))).
To understand how closures can be used as default header
arguments, imagine you'd like to set the file name output of a
@@ -500,7 +502,16 @@ this with:
Because the closure is evaluated with point at the source block,
the call to `org-element-at-point' above will always retrieve
-information about the current source block.")
+information about the current source block.
+
+Some header arguments can be provided multiple times for a source
+block. An example of such a header argument is :var. This
+functionality is also supported for default header arguments by
+providing the header argument multiple times in the alist. For
+example:
+
+'((:var . \"foo=\\\"bar\\\"\")
+ (:var . \"bar=\\\"foo\\\"\"))")
(put 'org-babel-default-header-args 'safe-local-variable
(org-babel-header-args-safe-fn org-babel-safe-header-args))
--
2.31.1
