Topic/additional functions

[ethul]

I salvaged a few functions from purescript-angular before removing the ST module there. I had been debating sending this PR, but perhaps you might find these useful (as per ethul/purescript-angular#5).

I also added getElems and getAssocs. I was on the fence about these, so if you don't think they are needed, I can definitely remove them. Additionally, I've changed the return type of pushSTArray to Number from Unit. I am not sure if this was the right thing to do, but I could go either way.

[paf31]

Thanks! This looks great.

I was going to say that I thought getElems was unsafe, but now I see that you're copying the array, which is good. I wonder about the name though - in Haskell, I believe it would be called freeze, which I quite like.

Also, maybe getAssocs could be renamed to toAssocArray? Just a thought, totally up for discussion...

[ethul]

Welcome!

I wasn't actually sure if it should be getElems or freeze. I am open to either. Both exist in Haskell. If you have a preference, I can make the name change.

For getAssocs, I'd be happy to rename it to toAssocArray, but I was just keeping with the function name in Haskell. Should we depart from the Haskell name?

[ethul]

Actually, it looks like getElems and getAssocs are on Data.Array.MArray. I don't think I am familiar enough with these mutable array modules in Haskell yet to make a good naming choice here. What do you think? I am happy to go with your suggestions here.

[paf31]

Oops, I guess I don't know MArray as well as I thought.

The only reason I would prefer freeze is that it would be consistent with the new functions in Data.Map.ST:

https://github.com/purescript/purescript-maps/blob/master/src/Data/StrMap.purs#L81

[ethul]

Sounds good. I've updated the names and added thaw.

[paf31]

👍 Thanks!

This makes me wonder if we should also

• Rename the existing functions: pushSTArray is unnecessarily verbose IMO - push would be enough, given qualified imports.
• Add a copy function: copy = freeze >=> thaw

[ethul]

Thanks!

I think the function renaming is a great idea. I am in favour of the shorter names and using the module name for context.

Good call on copy too!