You could also use the new zip_with:
Map.new(Enum.zip_with(list, 0..length(list), & {&2, &1}))
On Tue, 8 Dec 2020 at 23:51, Christopher Keele <[email protected]>
wrote:
> I think that even if it enabled awesome optimization opportunities,
> 1. Having both *Enum.index_with* and *Enum.index*/*indexed* will confuse
> people.
> 2. Straying from Elixir's consistent API design of "Module X functions
> take X's as their first argument" will confuse people.
> a. Especially in the very consistent and large-surface-area *Enum*
> module.
>
> Both together seem like a less-than-ideal combination. These trade-offs
> may be worth it depending on what is gained, though.
>
> I hadn't seen the second point mentioned yet in this thread yet. Which
> makes me wonder if there is a *different* module it might belong under,
> instead, resolving both problems while preserving the intention-revealing
> *index* function name?
>
> ie: *Integer.index(start \\ 0 :: non_neg_integer, Enum.t) :: Enum.t*
> Kind of communicates that we are indexing an enumerable by an integer
> value; and just appears a little non-standard when we omit the starting
> point.
>
> Creating a new module namespace for such a function to live--ex *Index*--seems
> a little excessive in this case, a costly increase in the surface of the
> standard library. (Is *Enum.Index.by/2 <http://Enum.Index.by/2>* unreasonable?
> Probably.)
> Worth nothing that these sorts of one-off-function discussions are exactly
> how some modules we have today came into being, though--*Atom* and *Tuple*
> come
> to mind. But "indexes" are hardly first-class language concepts.
> On Tuesday, December 8, 2020 at 2:02:13 PM UTC-8 [email protected] wrote:
>
>> There is a bit of a collision with the option for the offset, but you
>> could pattern match that.
>>
>> -bt
>>
>> On Tue, Dec 8, 2020 at 4:57 PM Zach Daniel <[email protected]> wrote:
>>
>>> I like that idea a lot Bruce. Let’s you do something like:
>>>
>>> maps |> Enum.with_index(&Map.put(&1, :index, &2))
>>>
>>> On Tue, Dec 8, 2020 at 4:50 PM Bruce Tate <[email protected]> wrote:
>>>
>>>> Maybe a transform function on with_index?
>>>>
>>>> Enum.with_index([:a, :b, :c], &{&2, &1})
>>>>
>>>> -bt
>>>>
>>>> On Tue, Dec 8, 2020 at 3:05 PM José Valim <[email protected]> wrote:
>>>>
>>>>> I would like to propose an Enum.index/2 function. It behaves like
>>>>> with_index/2 but the index is the first argument:
>>>>>
>>>>> iex> Enum.index([:a, :b, :c])
>>>>> [{0, :a}, {1, :b}, {2, :c}]
>>>>>
>>>>> I am hoping it reads "index" this tuple (hence the index as the first
>>>>> element. While with_index means attach an index information to each
>>>>> element
>>>>> (hence the second element). Is this sound?
>>>>>
>>>>> Thank you,
>>>>>
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>>>>> .
>>>>>
>>>>
>>>>
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>>>> CEO
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>> To view this discussion on the web visit
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>>
>>
>> --
>>
>> Regards,
>> Bruce Tate
>> CEO
>>
>>
>> <https://bowtie.mailbutler.io/tracking/hit/f8218219-d2a8-4de4-9fef-1cdde6e723f6/c7c97460-016e-45fb-a4ab-0a70318c7b97>
>>
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>> 512.799.9366 <(512)%20799-9366>
>> [email protected]
>> grox.io
>>
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