How to preserve order of associative array?

How to preserve order of associative array?

[Dominik Ritter]

Hi everyone!

I struggle to the order of an associative array right. If I take the
example from zsh-lovers man page:

    $ typeset -A ass_array; ass_array=(one 1 two 2 three 3 four 4)
    $ print ${(k)ass_array} # prints keys
    one four two three
    $ print ${(v)ass_array} # prints values
    1 4 2 3

I would expect that to be the keys sorted as they appear in the array
(one, two, three, four).

I tried to sort them in array index order, but without luck:
print ${(ak)ass_array}

The other sort-modifiers won't help me, as I need a hierarchy in my
array keys (neither lexically, nor numerical).

Thanks for any help. Regards,
Dominik

Re: How to preserve order of associative array?

[Mikael Magnusson]

On Sat, Nov 7, 2015 at 5:11 PM, Dominik Ritter <dritter03@googlemail.com> wrote:
> Hi everyone!
>
> I struggle to the order of an associative array right.

Associative arrays are unordered.

-- 
Mikael Magnusson

Re: How to preserve order of associative array?

[Bart Schaefer]

On Nov 7,  5:11pm, Dominik Ritter wrote:
}
} I struggle to the order of an associative array right.

Second paragraph in the doc under "Parameters":

  The attributes of a parameter determine the _type_ of its value, often
  referred to as the parameter type or variable type, and also control
  other processing that may be applied to the value when it is referenced.
  The value type may be a _scalar_ (a string, an integer, or a floating
  point number), an array (indexed numerically), or an _associative_
  array (an unordered set of name-value pairs, indexed by name, also
  referred to as a _hash_).

You can simulate an ordered set of name-value pairs like this (need zsh
version 5.1 for assigning to an array during typeset):

    typeset -a ord_array=(one 1 two 2 three 3 four 4)
    print ${ord_array[ord_array[(i)three]+1]}

Re: How to preserve order of associative array?

[Dominik Ritter]

>   The attributes of a parameter determine the _type_ of its value, often
>   referred to as the parameter type or variable type, and also control
>   other processing that may be applied to the value when it is referenced.
>   The value type may be a _scalar_ (a string, an integer, or a floating
>   point number), an array (indexed numerically), or an _associative_
>   array (an unordered set of name-value pairs, indexed by name, also
>   referred to as a _hash_).

Thank you very much. That explains it. I've overseen that in the documentation.


> You can simulate an ordered set of name-value pairs like this (need zsh
> version 5.1 for assigning to an array during typeset):
>
>     typeset -a ord_array=(one 1 two 2 three 3 four 4)
>     print ${ord_array[ord_array[(i)three]+1]}

Perfect! I'll try that. Thanks.

Re: How to preserve order of associative array?

[Bart Schaefer]

On Nov 10,  9:52pm, Dominik Ritter wrote:
}
} >     typeset -a ord_array=(one 1 two 2 three 3 four 4)
} >     print ${ord_array[ord_array[(i)three]+1]}
} 
} Perfect! I'll try that. Thanks.

I should note that this can fail if the same strings can appear as both
keys and values.