I want to add elements from a 2D arraylist to a multimap but cant find an equivalent method to getOrDefault as in case of hashmaps.
I tried using the guava library but seems like it does not have any deafult method for doing the same.
can someone help me with some other approach
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We have a Kotlin package that we native build and export to C. We have the header file with all the nested struct and pinned-style pointers.
In the Kotlin code, there is a Map which we want to access. We can get a hold of the Kotlin package enum (the key of the Map), but what's the C code for actually indexing into the "kref kotlin Map object" to get to the value in the map?
Basically, we'd like to know how to manipulate Map, List and Array from C code. Actual steps and/or reference doc would be appreciated.
Kotlin/Native compiler does not export any of the collection's functions to the native library API. This decision was taken some time ago, with the idea to minimize the verbosity of the library header. However, this leads to the problem you faced. Right now, the recommended approach is to write wrapper functions in your Kotlin code.For an example of this approach, please see this ticket at the Kotlin issue tracker. I also recommend subscribing to it, to get the updates on the problem's state ASAP. Posting this in case the ticket won't be available for someone:
fun getListElement(list: List<Any?>, index: Int) = list.get(index)
/// function accessing the list element by index
I have too components that deal with n-dimension array. One component is written in python which process the data and save the processed ndarray by tobytes(). Now the other component is written in java, which need to read the serialized ndarray produced in first component.
I am curious if there are any existing java libraries that can read serialized numpy array. Or there is a better way to communicate ndarray between java & python.
Any advice is appreciated!
Thank you!
ND4J supports reading from and writing to Numpy arrays. Look at the ND4J javadocs for xxxNpyYYYArray methods .
It can read and write from/to files, byte arrays and even raw pointers to a numpy array.
The pointer methods allow for using the arrays without copying or serialization. We use the pointer methods inside jumpy (which runs Java via pyjnius) and when using javacpp's cpython/numpy preset to run a cpython interpreter inside a Java process.
I have used Apache Arrow to solve this.
First the pyarrow package has a numpy ndarray API to serialize the array into bytes. Basically the ndarray becomes an Arrow bytes sequence batch.
Then the java API provides a VectorSchemaRoot to read it from the bytes. And you could get the values in the Arrow array. You could use this array to create ND4J array(if you need), or directly operate your array.
For detailed operations you could refer to Apache Arrow doc, and if any obstacles we could discuss here.
Also, Arrow uses native memory to store the buffer so the data is off the java heap. This may be an issue at some point.
Any other solutions could also share with me. :)
What implementation class is used to back the Set<E> and MutableSet<E> types returned by setOf() and mutableSetOf()?
Since the api documentation describes MutableSet as A generic unordered collection of elements, and since elements don't have to be Comparable, I'm guessing it's a HashSet but I can't find confirmation.
Taking a look inside Kotlin sources here and here, it seems that both return LinkedHashSet. There is an exception, in case setOf() is provided an empty list, it returns a singleton object (Kotlin object) which is defined at the top of the first file (link).
I've been creating PageObjects for WebDriverIO and have been following the ES6 method for Page Object pattern in the WebDriverIO documentation.
However, someone on my team suggested simply making objects of selectors, and then calling those strings in the tests. Is there a good reason why the Page Object pattern returns elements and not string of the selectors?
Page Object returns elements instead of just the selector string to allow actions to be called directly on the elements e.g.
PageObject.Element.waitForDisplayed()
Instead of you doing
Browser.waitForDisplayed(PageObject.Element)
Which may get lengthy and doesn't chain as well. You can find more actions that can be performed on elements here
However, you can also get the string of the selector if you want by doing
PageObject.Element.selector()
Chaining e.g.
PageObject.Element.waitForDisplayed().click()
I think the point is allow you to use the objects directly. So:
MyPageObject.MyElement.click()
versus:
browser.click(MyPageObject.MyElement)
Just a little less verbose
I am using the HtmlElement's InvokeMember function and was wondering if there is a nicely formatted list of all the strings that can be passed into that function.
So far I know about these strings that can be passed into InvokeMember:
Click, Focus
Can somebody provide a link to a list of all strings that can be passed into the InvokeMember function or write them down?
MSDN has the list of all the documentation for the classes in the .NET Framework. Here is HtmlElement's documentation listing all of its members:
http://msdn.microsoft.com/en-us/library/system.windows.forms.htmlelement.aspx