Re: [PATCH] Possibility of using alternative separators in macros

[Maxim Nikulin]

On 03/05/2021 04:08, Christian Moe wrote:
> I frequently need to escape commas in macros, which is a bit of a pain
> and easy to forget.

Maybe it is not convenient, but if unescaped comma is a real pain, you 
could detect it and report an error

# single line may be wrapped by mailer
#+MACRO: extraerror (eval (if (not $2) (concat "*" $1 "*") (error 
(format "%s: unescaped comma %S" (line-number-at-pos) $2))))

{{{extraerror(valid)}}}
{{{extraerror(valid\, with escaped comma)}}}
{{{extraerror(missed, comma)}}}

Org gurus might suggest a recipe how to convert error into warning, that 
is easily noticeable but still not fatal, to get all problems after 
single export attempt. Preferably it should act similar to compiler 
errors allowing to jump between problem points.

Org 9.3 requires a bit different macro
#MACRO: extraerror (eval (if (equal "" $2) (concat "*" $1 "*") (error 
(format "%s: unescaped comma %S" (line-number-at-pos) $2))))

> Another point: Something that would help, without adding new syntax, is
> making macro expansion smart enough to *ignore* separators when the
> macro definition contains only *one* argument anyway, as in the cases
> above.

I think, this is an idea of the best approach. Unsure concerning precise 
form. Maybe e.g. "$_" could expand into all arguments greater than 
maximum referenced number. No promise of forward compatibility of the 
following hack since it relies on undocumented implementation details.

#+MACRO: allargshack (eval (format "- /%s/ :: %s" $1 (mapconcat 
#'identity _ ",")))

{{{allargshack(one, two, three)}}}

I do not know if Eric can swap order of arguments of his credits macro. 
Extracting namely last argument requires a bit more lisp code.