java.util.stream 'map' method, proposal of method name change

[Remi Forax]

On August 15, 2017 6:51:00 PM GMT+02:00, Jonathan Bluett-Duncan <jbluettduncan at gmail.com> wrote:
>Hi Krunoslav,
>
>I think the reason the method was named `map` rather than `replaceWith`
>or
>an equivalent name, is because `map` is a well-known name for this
>sort of *higher-order
>function*. The name itself has been around in functional programming
>languages like Haskell and Scala and programming models like MapReduce
>for
>decades.
>
>Thus it would make sense to me that the writers of `java.util.stream`
>named
>it `map` to follow the Principle of least astonishment
><https://en.wikipedia.org/wiki/Principle_of_least_astonishment>.
>
>(Why was it named that way? I admit I do not know, but someone else may
>be
>able to explain.)

the name comes from Lisp
https://en.m.wikipedia.org/wiki/Map_(higher-order_function)

>
>Hope this helps.
>
>Best regards,
>Jonathan

Remi 

>
>On 12 August 2017 at 03:36, Krunoslav Magazin <magazin9 at gmail.com>
>wrote:
>
>> Hi. When using java.util.stream 'map' method my opinion is that
>> 'replaceWith' as method name would better describe what method do.
>> 'map' method is applied on input stream, returns output stream but
>> returned stream elements are return values from 'map' method Function
>> argument. We continue our work with output stream so mapping with
>> input stream have no meaning. Input stream is replaced with output
>> stream which elements are outputs of Function. After that point we
>can
>> forgot about input stream.
>>
>> Example of usage:
>> now - stream.map(e -> e+2)..        // read: map input stream with
>> output stream containing elements resulting from function (e -> e+2)
>> proposed - stream.replaceWith(e -> e+2).. // read: replace input
>> stream with output stream containing elements resulting from function
>> (e -> e+2)
>>
>> With 'map' method number of elements is the same but we do not make
>> assumptions what passed Function will do (specialization) until the
>> moment we pass Function implementation as method argument..
>>
>> I will appreciate any comments.
>> Best regards,
>> Krunoslav Magazin
>>

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