[Tagging] Benefits of namespaces

François Lacombe fl.infosreseaux at gmail.com
Mon Dec 17 14:24:10 UTC 2018

Le lun. 17 déc. 2018 à 14:26, Sergio Manzi <smz at smz.it> a écrit :

> Sorry, I didn't meant to be rude in any way: I just assumed you were the
> one who introduced the switch=* key for power lines (*and apparently I
> was wrong, you just "expanded" the information about those...)*

Me neither, switch=* was firstly de facto used and then documented on wiki
with a proposal.

> Bingo. Now try substituting the "=" sign with the ":" sign

This would be redundant with railway=switch and power=switch :)
Be sure I'll be blamed for that just like I'm blame to don't use namespaces.

> If you do the same inside an objects description, an editor or data
> consumer could instantly "*route*" you to the relevant documentation when
> you are inspecting that particular object (*either a railway switch or a
> power switch*).
Editors like JOSM have context=x" concept to make the distinction.
JOSM maintainers told me they prefer actuator=* as it's more simpler to
type and users don't have to be annoyed with that.
I understand that editors have more work to do to deal with such generic
keys, but editors should help users and not the contrary shouldn't you ?

> Yes, the context (*either we find the "switch" keyword inside the
> definition of a power line, a railway or a network*) can imply the
> lexical scope of the keyword, and most of the times that's self-evident for
> us humans, but it is a lot more difficult to *teach *to a program.
That's not so clear depending on which editor maintainer you ask.
Processors have to deal with tags associations, namespaces won't prevent
them to be smart anyway i'm affraid.

> Then actuator is an attribute of several kind of objects (pipeline=valve
> and eventually railway=switch), just like location.
> I don't get where I confuse something between actuator=* like tags and
> location=*
> Here is where I think you make the mistake.
> The actuator is *not an attribute* of the things (pipeline=valve and
> eventually railway=switch), but a *part/element* of them.
> Someone someday may be wishing to further describe actuators in their own
> details/attributes, like now you are doing for valves which are
> parts/elements of a pipeline.
Currently it is an actual attribute for sake of simplicity for contribution
and inventory, because we consider the system {valve + actuator}.

Then in eventual future, we will need another node to separate the actuator
from the valve and a way connecting the valve and the actuator to map the
mechanical link.
That should be done for transformers on top of poles, antennas on top of a
mast, windows on a given house and so on...

By the way I apreciate the discussion and this certainly improve the
knowledge about tagging possibilities and principles.

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