Hi, when using the get() operator overload, what type of info do you get when you put multiple parameters in there? for example

val x = object[5,3]

What type of data is the 5, 3 representing.

nothing, it works just like a normal method call

this would be for

operator fun Object.get(value: SomeDataType){}

if that's the only

operator fun get

then you can't write

object[i, j]

It would not default to an IntList?

no

So I have a project where I am duplicating numpy's ND array. What would be the best way to get that index of my value through the get operator?

vararg

could vararg take in colons in order to select sections of my array objects?

no, colon syntax for ranges does not exist in Kotlin. you could accept IntRange though, e.g.

operator fun get(range: IntRange)

object[1..5]

How would this work for a custom 2d array?

there's no type-safe way to accept a variable mix of Int and IntRange, but if your dimensionality is fixed at d=2,

operator fun <T> Array2D<T>.get(x: Int, y: Int): T
operator fun <T> Array2D<T>.get(x: Int, y: IntRange): Array1D<T>
operator fun <T> Array2D<T>.get(x: IntRange, y: Int): Array1D<T>
operator fun <T> Array2D<T>.get(x: IntRange, y: IntRange): Array2D<T>

isn't too many overloads to deal with

But for N dimensional?

statically, you can't determine the types

Maybe ill just build a string parser.

something like

operator fun ArrayND.get(vararg indices: Any): Any

would allow for any mix, with the logic inside attempting to cast to Int or IntRange, but it can't be done in a type-safe manner. the caller will also have to perform an unsafe cast

What would you mean by its unsafe?

object[String, Object, List, Map, Array]

would compile

So I would have to make a set of rules that get parsed from the vararg and through an error if there is something other than an finite range or finite value.

there are no infinite ranges in Kotlin

Sorry meant whole.

to elaborate, in my opinion it would be a better Kotlin API to separate

object[x, y, z]

0-D and

object.slice[x][y..y][z].asArrayND()

, where

operator fun <T> ArrayND<T>.get(vararg indices: Int): T
val <T> ArrayND<T>.slice: Slice<T> get() = ...
operator fun <T> Slice<T>.get(index: Int): Slice<T>
operator fun <T> Slice<T>.get(index: IntRange): Slice<T>

Thank you very much. I think this will work.

in what way? conversions to/from collections or arrays, providing wrapped views around arrays, views as collections? all should be possible. depends on what you're using though

I was mainly building this library as a numpy replacement built off of ArrayND but many of the Array methods look very useful. I am still learning the kotlin style guide.

standard collections methods like

.map()

etc? that would make sense, although it might be hard to find reasonable semantics for others like

.filter()

I mainly wanted something easy to use like matlab or numpy.