[erlang-questions] Bound(?) var in anonymous fun

[Pablo Vieytes]

I have to get used to use list comprehension. I know how it works but I
never remember use it.






2012/12/18 Loïc Hoguin <essen@REDACTED>

> This one only removes the first element. :)
>
>
> On 12/18/2012 12:34 PM, Max Bourinov wrote:
>
>> Or even more shooter:
>>
>> lists:delete(Key, StatusList).
>>
>>
>> On Tue, Dec 18, 2012 at 3:22 PM, Dmitry Klionsky <dm.klionsky@REDACTED
>> <mailto:dm.klionsky@REDACTED>**> wrote:
>>
>>     On 12/18/2012 02:08 PM, Manuel A. Rubio "Bombadil" wrote:
>>
>>         Hi Pablo,
>>
>>         El 2012-12-18 11:54, Pablo Vieytes escribió:
>>
>>             I guessed Key was bound so I could use for pattern matching.
>>             It's
>>             very easy to fix it but I don't know why it doesn't work.
>>
>>
>>         This doesn't works well because the params are not inside of
>>         binding in closures. The params are the interface with the
>>         outside world and will be confuse know if a param is a binding
>>         or not. By default Erlang hasn't binding in function params.
>>
>>             Fixed version:
>>
>>             delete_key_from_list(Key, StatusList)->
>>                  lists:foldr(
>>                    fun(K, Acc) when K == Key ->
>>                    Acc;
>>               (Another, Acc) ->
>>                    [Another|Acc]
>>                    end,
>>                    [],
>>                    StatusList).
>>
>>
>>         This code could be writted as:
>>
>>         delete_key_from_list(Key, StatusList)->
>>              lists:filter(fun(X) -> Key =/= X end, StatusList).
>>
>>         Regards,
>>         Manuel Rubio.
>>         ______________________________**___________________
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>> >
>>
>>
>>     Or even more readable as:
>>
>>     delete_key_from_list(Key, StatusList)->
>>          [Status || Status <- StatusList, Status =/= Key].
>>
>>     --
>>     Best regards,
>>     Dmitry Klionsky
>>
>>
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>>
>>
>>
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>
> --
> Loïc Hoguin
> Erlang Cowboy
> Nine Nines
> http://ninenines.eu
>
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