Обсуждение: Documentation bug?

Hello all,

I just noticed that you can do something like this (using 9.4.1):

   select array[1,2,3] - 3

which is doing the same thing as:

   select array_remove(array[1,2,3],3)

but the minus is not documented as an array operator:
http://www.postgresql.org/docs/current/static/functions-array.html 

Is that an oversight in the documentation or isn't the minus supposed to work like that in the first place?

Regards
Thomas

Thomas Kellerer wrote:
> I just noticed that you can do something like this (using 9.4.1):
> 
>    select array[1,2,3] - 3
> 
> which is doing the same thing as:
> 
>    select array_remove(array[1,2,3],3)

I can't reproduce this on my PostgreSQL 9.4.1:

test=> select array[1,2,3] - 3;
ERROR:  operator does not exist: integer[] - integer
LINE 1: select array[1,2,3] - 3;
                            ^
HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.

Did you add casts or operators?

Yours,
Laurenz Albe

Maxim Boguk schrieb am 19.05.2015 um 13:33:
>     Hello all,
>
>     I just noticed that you can do something like this (using 9.4.1):
>
>        select array[1,2,3] - 3
>
>     which is doing the same thing as:
>
>        select array_remove(array[1,2,3],3)
>
>     but the minus is not documented as an array operator:
http://www.postgresql.org/docs/current/static/functions-array.html
>
>     Is that an oversight in the documentation or isn't the minus supposed to work like that in the first place?
>
>
> ​You very likely have an intarray extension installed​:​
> http://www.postgresql.org/docs/9.4/interactive/intarray.html
> int[] - int  operator documented in the extension documentation as it's a part of the extension but not part of the
PostgreSQLcore.​ 

Ah, right - that was it. Completely forgot about that.

Sorry for the noise.

Thomas