Is there a way to capture the index of the errors ...

# arrow

[bj0]

Is there a way to capture the index of the errors in mapOrAccumulate?

[Youssef Shoaib [MOD]]

Maybe something like:

list.withIndex().mapOrAccumulate { (index, element) ->
  withError({ e: MyErrorType -> e to index }) {
    
  }
}

[bj0]

so you have to store it in the error type? i was wondering if i could avoid modifying the error type

[Youssef Shoaib [MOD]]

How do you expect to use the error indices? I imagine you'd have to modify the error type regardless, no?

[bj0]

i guess i could create a new wrapper error with index

[Youssef Shoaib [MOD]]

Exactly yeah, and to an extent, that's what my solution does, but it just uses a Pair

[bj0]

oh I see, you're not using an explicit error type

[Youssef Shoaib [MOD]]

Oh yeah, the MyErrorType here is just whatever error that your code already throws

[bj0]

i mean, using pair results in a Either<Any, T> instead of Either<ErrorType, T>

[Youssef Shoaib [MOD]]

It shouldn't tho. Do you have a code snippet maybe? I think accidentally you're using the mapOrAccumulate receiver instead of the withError one

[bj0]

i was returning a pair in one spot and an error in another, so it was inferring Any, i just wrapped it in a new error type so I could use my error interface

[bj0]

this is what i have atm:

ranges.withIndex().mapOrAccumulate { (idx, range) ->
            val low = withError({ IndexedError(idx, it) }) { range.first.parseFreq() }
            val high = withError({ IndexedError(idx, it) }) { range.second.parseFreq() }
            ensure(low.valueInHz < high.valueInHz) {
                IndexedError(idx, InvalidInput("low value must be lower than high value"))
            }
            low to high
        }

[bj0]

i guess i could have also used IndexedValue<T>