Re: [ANN] BREAKING CHANGE -- removing #+BABEL file-wide property lines

[Eric Schulte <schulte.eric@gmail.com>]

It is now possible to specify multi-line properties using a property
block.  This should make it more natural to specify many file-wide
variables through properties.  For example,

  #+begin_property
    var foo=1,
        bar=2,
        baz=3,
        qux=4
  #+end_property

  #+begin_src emacs-lisp
    (+ foo bar baz qux)
  #+end_src

  #+results:
  : 10

Cheers -- Eric

Darlan Cavalcante Moreira <darcamo@gmail.com> writes:

> I didn't check the list for 3 days and this thread became a little hard to
> follow. So, forgive me if I'm "answering" the wrong E-Mail.
>
>
> I liked Christian's idea of using a single "var" property to tell babel
> which regular properties it should use as variables (ignoring any variable
> not defined). This would be enough for my use cases.
>
> On the other hand, some way to append values to a property, such as using
> some special keyword as I have suggested, could be a better solution in
> order to keep consistence if people want this feature for non-babel related
> properties.
>
> --
> Darlan
>
> At Sat, 22 Oct 2011 09:53:25 -0600,
> Eric Schulte wrote:
>> 
>> Darlan Cavalcante Moreira <darcamo@gmail.com> writes:
>> 
>> > It's excellent that now babel understands multiple values in the "var"
>> > property (I was one of the people that wanted this), but "There Is One More
>> > Thing".
>> >
>> > Would it be feasible to inherit variables from parent sub-trees?
>> > Effectively, I'd like to append new values in lower level sub-trees, but
>> > AFAIK setting the var property in a sub-tree will still replace the value
>> > set in the parent sub-tree.
>> >
>> 
>> Currently every new property specification entirely replaced previous
>> specifications with the same name.
>> 
>> >
>> > That is, in the example below the level-2 sub-trees would not have the foo
>> > variable passed to babel.
>> > * Code with foo
>> >   :PROPERTIES:
>> >   :var:      foo=1
>> >   :END:
>> >
>> > ** Code only with bar
>> >    :PROPERTIES:
>> >    :var:      bar=2
>> >    :END:
>> >    src_block
>> > ** Code only with baz
>> >    :PROPERTIES:
>> >    :var:      baz=3
>> >    :END:
>> >    src_block
>> >
>> > Maybe a special keyword, such as "inherit" (or "append") could be used to
>> > incorporate variables defined in the parent sub-tree, such that the example
>> > would become
>> > * Code with foo
>> >   :PROPERTIES:
>> >   :var:      foo=1
>> >   :END:
>> >
>> > ** Code with foo and bar
>> >    :PROPERTIES:
>> >    :var:      bar=2, inherit
>> >    :END:
>> >    src_block
>> > ** Code with foo and baz
>> >    :PROPERTIES:
>> >    :var:      baz=3, inherit
>> >    :END:
>> >    src_block
>> >
>> > This should not affect global variables and "inherit" would inherit
>> > variables defined only in the parent sub-tree (unless it also contains the
>> > inherit keyword).
>> >
>> > As a use case scenario, suppose I need to perform simulations for a few
>> > different scenarios, each with small variations. This would allow me to
>> > define common variables for a scenario in a higher level sub-tree and more
>> > specific variables in the lower level sub-trees.
>> >
>> 
>> This sounds somewhat similar to my suggestion in reply to Rainer's
>> email.
>> 
>> Best -- Eric
>> 
>> >
>> > --
>> > Darlan Cavalcante
>> >
>> >
>> > At Fri, 21 Oct 2011 22:24:25 +0200,
>> > Christian Moe <mail@christianmoe.com> wrote:
>> >> 
>> >> Hi,
>> >> 
>> >> Yes, that works nicely, and should solve Rainer's problem.
>> >> I haven't been able to think of anything else that can't be handled by 
>> >> properties.
>> >> 
>> >> And I do think it's a good idea to winnow down the syntax a bit, even 
>> >> if things break. I just like to grumble.
>> >> :-)
>> >> 
>> >> Yours,
>> >> Christian
>> >> 
>> >> On 10/21/11 7:37 PM, Eric Schulte wrote:
>> >> > Nice idea.  This same issue with "var" arose when we first started
>> >> > allowing header arguments to be specified inside subtree properties.
>> >> > I've just implemented your suggestion so the following are now possible.
>> >> >
>> >> > #+PROPERTY: var foo=1, bar=2
>> >> > #+PROPERTY: cache yes
>> >> >
>> >> > #+begin_src emacs-lisp
>> >> >    (+ foo bar)
>> >> > #+end_src
>> >> >
>> >> > #+results[be32e67491d4e92f75769aebe423c20ca01626fe]:
>> >> > : 3
>> >> >
>> >> > and
>> >> >
>> >> > #+begin_src emacs-lisp :var foo="this", bar="that"
>> >> >    (concat foo " " bar)
>> >> > #+end_src
>> >> >
>> >> > #+results[3cde077efa81f1ca24a62ac264dbd5776b6e0054]:
>> >> > : this that
>> >> >
>> >> > Thanks for the suggestion and I hope the above is a sufficient
>> >> > replacement for the now-missing #+BABEL: syntax.
>> >> >
>> >> > Cheers -- Eric
>> >> 
>> >> 
>> 
>> -- 
>> Eric Schulte
>> http://cs.unm.edu/~eschulte/

-- 
Eric Schulte
http://cs.unm.edu/~eschulte/