Re: org-agenda queries for absent properties

[Ihor Radchenko]

Jens Schmidt <jschmidt4gnu@vodafonemail.de> writes:

> The following was initially meant as bug report until I understood that
> it's actually some sort of feature ...
>
> since the absent property "patchday" on the "relax" todo entry is
> defaulted to value zero, obviously.

This is a side effect of handling comparison operators in tag matcher.
The property value is processed as (string-to-number (or value "")). And
since (string-to-number "") => 0, you get what you get.

This code is out there since the beginning of git history.

> So I would like to have something easier to type (and remember! why not
> "!=" or "/="?) then

Not "!=" and "/=" is because parsing of match string is too dumb. See
`org-make-tags-matcher'.

>    patchday<>0&patchday<=202305
>
> How about starred agenda property operators that match only if the
> operand property is actually present, which would result in this query:
>
>    patchday<=*202305
>
> Section <info:org#Matching tags and properties> does not seem to provide
> any information on "definedness" expressions for properties.

If you are up to a job of adding this to `org-make-tags-matcher' and not
breaking things, you can try. But we should really provide more readable
match syntax, similar to org-ql; sooner or later.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
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