range with units

[dvd101x]

Hello,

I've encountered the need to make a range with units, let's say [1 s, 1.1 s, 1.2 s].

It would be nice for range to accept units like range(1 s, 1.2 s, 0.1 s) or range(1 s, 1.2 s, 100 ms).

A work around was using range(1, 1.2, 0.1) s, but it would be nice for range to accept units so we could mix and match like range(1 s, 0.02 minute, 1 ds).

I may be able to import the type to range but I was wondering if this would be desirable for this project.

[josdejong]

It is an interesting idea, thanks for sharing! I think the step size should be required in that case, there is no way to know what unit the default step of 1 should have.

[dvd101x]

An alternative would be for the step size to have the unit of the first argument like range(30 s, 1 minute) being equivalent to range(30 s, 1 minute, 1 s).

It may be confusing, I'm just saying it might be possible.

In a similar way we can currently do range(0, -4) getting an empty array because the step size of 1 might not be what we intended and we need to specify it range(0, -4, -1). Might be similar to doing range(0.5 minute, 1 minute) getting an array with only [0.5 minute] thus we would need to either change the units range(30 s, 1 minute) or specifying the step size range(0.5 minute, 1 minute, 1 s).

[josdejong]

Yes it will be possible, but indeed I think it will be confusing. For example, what would range(5cm + 2inch, 20cm) do? Would it give a different result when doing range(2inch + 5cm, 20cm)?

I think it would be best to simply make the step required to prevent any confusion.

[dvd101x]

You are right, I didn't think of that case.

[dvd101x]

Hi Jos, I was checking the possibility to include units in range and I have a few questions:

• In the factory function I noticed some dependancies with ? like ?matrix. What does it mean?
• If I try to include a dependance like isPositive I get an error:
  Error: Cannot create function "range", some dependencies are missing: "?matrix", "?bignumber", "isPositive". I would like to know what I'm doing wrong and what does it have to do with the dependancies starting with ?
• I noticed that the same logic is repeated on different functions to check if the iteration is still ongoing depending on the direction of step and if the range end is excluded. Would it be desirable if the logic was inside a function to represent that logic?

[josdejong]

1. The ? in dependencies means the dependency is optional. In that case the implemented function must check whether the dependencies is available or not.
2. This is not related to the optional dependencies with a ?. It means that somewhere, createRange is invoked without this new dependency isPositive. Doing a search for createRange( results in one place where it is hard-coded: inside range.transform.js. So you'll have to add the dependency there too. Though it is quite hidden, this file pops up in the stack trace of the error too.
3. If you see ways to simplify the code by extracting reused logic, I'm all in! (unless the refactored code becomes harder to understand or more complex than the original)

[dvd101x]

Thanks! everything is clear now.

My bad, I didn't notice the transform in the stack trace of the error.

[dvd101x]

I included #2997 for this