technical | Various indicators developed or collected for the Freqtrade

Interface is a concept of Object Oriented Programming. When you say that an object type implements an interface, you are talking about a property of that type. It says that the type follows certain contract.

Rust is not an object oriented language. And traits are not exactly interfaces. When you say, that a struct has some trait, it does not necessarily mean, that it is a property of the struct, but rather that struct maps with the functionality of the trait.

For example, you can have a built-in rust type [f32; 2] - an array with two values. And you can have a trait Point:

You may use an anonymous function

Raku's syntax is defined as a Raku grammar. The rule for parsing such a comment is:

In Haskell, the square brackets mean a list, as they also do in Python. Haskell also uses white space syntax.

You can tell what type a String is in Haskell by using :t in the ghci REPL.

The C# specification says the following (my bold):

23.4 Fixed and moveable variables

The address-of operator (§23.6.5) and the fixed statement (§23.7) divide variables into two categories:
Fixed variables and moveable variables.

...snip...

The & operator (§23.6.5) permits the address of a fixed variable to be obtained without restrictions. However, because a moveable variable is subject to relocation or disposal by the garbage collector, the address of a moveable variable can only be obtained using a fixed statement (§23.7), and that address remains valid only for the duration of that fixed statement.

In precise terms, a fixed variable is one of the following:

• A variable resulting from a simple-name (§12.7.3) that refers to a local variable, value parameter, or parameter array, unless the variable is captured by an anonymous function (§12.16.6.2).
• .....

So it's explicitly forbidden by the spec. As to why it's forbidden, for that you would have to ask the language designers, but considering how much complexity is involved in capturing variables, it is somewhat logical.

Well, https://bugzilla.mozilla.org/show_bug.cgi?id=1693295 capped the Windows version at 10 for Firefox, so that's really not going to work for you...

One way I can think of is to make a mutable copy of a, and try to remove every element of b, then check if all elements of b can be removed:

We could contact a Google Consultant. After some weeks of back and forth, we got confirmation from a Google technical team about it. And they confirmed, that we can do our plan as described in the question. It will work.

We can do a full rollout to all countries, afterwards a staged rollout to selected countries affecting 100% of those users, and later we can add the missing countries, and the rollout becomes full release.

Maven is a tool that has certain opinions on where things should go; a default configuration. You don't have to follow it, but not following this default configuration has three significant downsides:

• You do have to then configure maven to tell it about the alternative choices you made. Maven does not make this easy.
• Other java programmers generally assume the defaults. If you have a good reason to deviate, go for it, but 'I do not like it' is not a good reason, as it'll be pointlessly increasing the learning curve.
• The maven developers chose this structure as default for a reason. If you think it's a dumb reason, that's certainly possible and you may even be right, but then you're using a build tool written by folks who, (judging the book by its cover a little bit), according to you, make boneheaded choices about sane defaults. That's not a great place to be.

To explain each layer:

Indicates that these are source files: Compiled and generated stuff should not be in here, and the entire src tree should be in version control. Contrast to e.g. bin or build containing build artefacts, doc containing documentation, and who knows what other directories you need for other relevant parts of a repo.

A project can consist of multiple separately buildable artefacts and 'kinds' of product. For example, most projects include a bunch of code that exists solely for testing purposes (the unit tests). They live in src/test. The core product lives in main. You can also have for example separate sources for an installer perhaps (src/installer), or a build plugin, or an annotation processor that needs to be built first and then it needs to be on classpath when compiling the main project, etcetera.

There's such a thing as split language projects, where some of it is written in language A and some of it in language B. For its worth, I think this layer is bad design; A file ending in .java gives away how one is to 'compile it', and this goes for just about every source file that needs a compiler applied to it: The extension says just as much as a folder name of java ever could. To show you a common contrast: Many projects have src/main/resources as well as src/main/java: Resources are 'compiled' simply by copying them over: Imagine your app has a text file containing a list of all US states with all zipcodes used in each state. Or png files with icon images for a GUI app. Such files are just as much part of your main application as the class files would be and should end up in the same place (inside the jar file), but to 'compile' them, you just.. copy em, you don't run javac to do this. That's what this level is about: What tool should be used to turn source files into distributable aspects?

This matches the java package structure. This is effectively a requirement applied by javac itself. The reason to use such a deeply nested package structure is simply because packages serve as namespaces: If there is a conflicting fully qualified name, all hell breaks loose: Java simply cannot handle this. Hence, java programmers ensure that such conflicts never happen by using a 'reverse domain name' structure: You'd stick your project in that package if you own the zeus.lab.co domain, thus ensuring nobody except other folks in your team who share control of that server could possibly be in conflict (and for those: They're in your team, talk to them to avoid conflict). For example, there are 3 different open source java projects all called spark. Had they all gone with package spark; (and thus, src/main/java/spark/Main.java as an example file), then for every java project you'd pick one of the 3: The other 2 you can never use in this project. Harsh, and pointless, which is why (almost) all java libraries use a reversed domain name as root package name, and then maven follows this package name in its directory structure because javac makes life extremely difficult if you don't do that.

That gets us to project_name/src/main/java.

You made that up for hyperbole. Nobody hosts a proj on zeus.lab.co.bah.org. But if they do: Talk to the management that decided to assign that whopper of a domain name to a team. It's on them, not on the author of this project.