Re: [bug-gawk] On uninitialized variables

[M]

In addition, concerning the fourth example:

$ gawk 'BEGIN { if (! isarray(x)) { print typeof(x) } }'
untyped

According to the manual:

"And in fact, due to the way gawk works, if you pass
the name of a variable that has not been previously used to isarray(), gawk
ends up turning it into a scalar."

So, I expected to see "unassigned" in the output.
However, there is "untyped" in the output.

_______________

Yours respectfully,
Mark Krauze

13.05.2019, 22:52, "M" <address@hidden>:
> Thank you!
> And another question about unassigned variables.
> When does a variable with a type "untyped" turn into a type "unassigned" (and 
> vice versa, if it's even possible)?
>
> With GNU AWK v5.0.0 I have the following:
>
> $ gawk 'BEGIN { print typeof(x) }'
> untyped
> $ gawk 'BEGIN { print typeof(x); print typeof(x) }'
> untyped
> untyped
> $ gawk 'BEGIN { if (x == "") { print typeof(x) } }'
> unassigned
> $ gawk 'BEGIN { if (! isarray(x)) { print typeof(x) } }'
> untyped
> $ gawk 'BEGIN { if (! x) { print typeof(x) } }'
> unassigned
>
> In the section "9.1.7 Getting Type Information" for "untyped":
>
> "x has not yet been used yet at all; it can become a scalar or an array."
>
> As far as I understand x is "untyped" because it hasn't yet been used in a 
> scalar or array context.
> Am I right?
>
> If it is so, there are some functions like "typeof" or "isarray" which don't 
> define a context, so to speak.
> I don't know how many of them there are.
> Thus (theoretically) you can _use_ a variable x, but after such operations it 
> still has a type "untyped".
>
> _______________
>
> Yours respectfully,
> Mark Krauze
>
> 13.05.2019, 22:11, "address@hidden" <address@hidden>:
>>  Hi.
>>
>>  M <address@hidden> wrote:
>>
>>>   Hello! When rereading the manual (v5.0.0), I noticed an inexact statement
>>>   in Chapter 1:
>>>
>>>   1.5 A More Complex Example
>>>
>>>   "(This works because awk variables are automatically initialized to
>>>   zero.)"
>>>
>>>   It's true only in a numeric context.
>>>   When used as strings, uninitialized variables are automatically
>>>   initialized to an empty string.
>>>   Although this peculiarity is emphasised throughout the rest of the manual,
>>>   I think it would be useful to mention about it in the introduction
>>>   chapter too (especially for novices).
>>
>>  Thanks for the note. Looking at the section as a whole, I think it
>>  would be distracting to try to introduce information about initialization
>>  to the empty string. Sometimes it's better not to be fully complete.
>>
>>  So, I appreciate your making the suggestion, but I think it better to
>>  leave that section alone.
>>
>>  Thanks!
>>
>>  Arnold