Collection.Indexed implementations inconsistently handle non-integer indices

[nex3]

The List class always seems to round non-integer indices down, while OrderedMap.entrySeq() seems to return undefined if the index isn't an exact representation of an integer. I haven't investigated other implementations to see if they differ. I'm not sure which behavior is better, but either way I'd expect them to be consistent.

const immutable = require("immutable");

console.log(immutable.List([[1, 2], [3, 4]]).get(0.1)); // [1, 2]
console.log(immutable.OrderedMap([[1, 2], [3, 4]]).entrySeq().get(0.1)); // undefined

[jdeniau]

I do not have the implementation in mind right now, but it's probably because a Map is key/value, so the key is strict, while a List accessor is numbered indexed, so 0.1 is converted to 0.

If something should be made, then probably the List should either return undefined or throw an error (but immutable does not really throw errors).

For the record : do you use Typescript? And if so, does it report an error?

[jdeniau]

I answer to my own question : as Typescript does not handle integer, 0.1 is a valid value for List.get