[Flightgear-devel] Nasal print() logging

[James T. <ja...@fl...>]

Mostly for Jules, but:

> src/Scripting/NasalSys.cxx: Optionally prefix all Nasal output with Nasal file:line.
> 
> Depends on /sim/nasal-log-file-line. E.g. enable with:
> 
>     --prop:/sim/nasal-log-file-line=1.

There’s some details here: we are deprecating and removing Nasal print() where possible in favor log logprint which takes a priority level.

This is part of the goal that we achieve zero output at log-level at alert, and everything shown at ‘warn; is really a warning, not just information.

Secondly, I don’t think there is any reasons to make this optional, there is no value in __FILE__ or __LINE__ for such a message, so you can skip the listener and just change the default.

Finally, C++11 nag, you used virtual rather than override for your listener, at least my IDEs yell at me for overrides which are not marked as such.

Related, I think it’s high time we added a lambda-listener to SGPropertyNode, to get rid of these trivial listener subclasses:

auto foo = prop->addValueChangeListener([](const SGPropertyNode* node) { …. });
// return value is an SGPropertryChangeListener*, internally will an instance of LambdaValueChangeListener : public SGPropertyCHangeListener
// this also allows re-use on other props

prop->removeChangleListener(foo);

Kind regards,
James