Multiple UserPropagators - z3

With the recent addition of UserPropagators, I'm wondering if the solver is able to safely support more than one in the same context?

Turns out this isn't supported, based on the discussion here: https://github.com/Z3Prover/z3/discussions/6382

Related

Does Apple provide a way to determine why a specific code is deprecated?

I'm currently maintaining legacy code project that requires me to resolve deprecation warnings for outdated iOS versions. Looking through documentation as well as Xcode warnings, I'm able to determine which methods are deprecated and recommendations on which methods should be used to replace deprecated code.
Out of curiosity, is there a way we can determine why a specific code was deprecated? Is there a system design explanation that tells us devs why this deprecation was needed? Thanks in advance.
There isn't anything built into the documentation. But by looking at the header and the replacement, and/or by watching the relevant WWDC video, you can usually get the point. (I've certainly never had any difficulty with this.)

Lidars in Drake

I want to simulate lidars. I saw that a class DepthSensor was mentioned in the documentation, but I have not found its actual implementation. For now, I am planning on using the RgbdSensor class and use only the height I need of the depth point cloud I receive to simulate my lidars.
Just to get your input on that, maybe I missed something, but is there a specific class for lidars, and how would you go about adding lidars to a simulation?
Thanks in advance,
Arnaud
You've discovered an anchronism in the code. There had previously been a lidar-like sensor (called DepthSensor). The extant documentation refers to that class. The class's removal should've been accompanied by a clean up of the documentation.
The approach you are taking is the expected approach given Drake's current state.
There has always been an intention to re-introduce a lidar-like sensor in Drake's current architecture. It simply hasn't been a high priority.
I'd recommend you proceed with what you're currently doing (lidar from depth images) but, at the same time, post an issue requesting a lidar-like query with specific focus on the minimum lidar-properties that you require. A discussion regarding how that would differ from what you can actually get from the depth images would better inform of us your unique needs and how to prioritize it. (You can also indicate more advanced features that you need less but would be good to have, of course).
As for the question: how would you go about adding lidars?
That's problematic. Ideally, what you would need is ray-casting ability. The intent is for QueryObject to support such a query, but it hasn't happened yet. (It's certainly the underlying technology we'd have used to implement a LidarSensor.) In the absence of that kind of functionality, you'd essentially have to do it yourself in the most horrible, tedious way imaginable. I'd go so far as to suggest that it's not feasible with the current API.

What does it mean an Apple implementation is deprecated while still being able to use it. Reasons not to use it?

I'm using GLKit's GLKView in one of my projects. As per Apple's documentation it is deprecated. I can still use it in my app and it is fully functional (for what I want it to do) with latest iOS versions. I'm using it because of an older SDK that I'm using has good functionality for it. What are reasons not to use it anymore?
If something is deprecated, that means they may remove it in future versions. If you continue to use it, your code may break next time you update the library.
They left it in despite being deprecated to give you an opportunity to switch to a new solution.
A function being deprecated means that it is still supported for now, but they are planning on deleting it. Often times this is because there is other better ways to achieve the same. A reason to not use it anymore is because it will very probably be deleted eventually.
You can use it now,but maybe can't in the future.Such as UIWebView just like Apple said:
Apple will stop accepting submissions of apps that use UIWebView APIs.
It's the same.

Why should we use lua_pushinteger()?

The current versions of Lua don't support integer numbers, only floats. (With the upcoming 5.3 this is changing, but let's ignore this.)
So, my question is: what use there is in lua_pushinteger()? If the numbers get cast into a float, why not use lua_pushnumber() directly?
(Please don't answer "for future compatibility with 5.3", which is a good answer for today but is an answer that otherwise doesn't satisfy my curisoty: integer support wasn't expected in the old days. I want to know the reason lua_pushinteger() was introduced in the first place, not apologetic in hindsight.)
The explicit handling of integers in the API was introduced for documentation, performance, and correctness.
Concentrating the handling of integers explicitly inside the API allows the core to use the best conversion to and from floats; in some platforms, this can be costly if done naively. It also allows the core to check for overflow, though Lua 5.1 and 5.2 did not check this.

Selectsinglenode in IXMLDOMElement?

can i perform select single node from IXMLDOMElement ,if its possible give me one example for that using MSXML
In what language? To solve what problem?
For what it's worth, the MSDN documentation for IXMLDOMElement::selectSingleNode can be found here, and includes samples in a few different languages.

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