Re: equivalent for C-style init: structname varname[] = {...} ?

[Sergei Steshenko]

----- Original Message -----
> From: Sergei Steshenko <address@hidden>
> To: Jordi Gutiérrez Hermoso <address@hidden>; "address@hidden" 
> <address@hidden>
> Cc: "address@hidden" <address@hidden>
> Sent: Sunday, November 18, 2012 7:52 PM
> Subject: Re: equivalent for C-style init: structname varname[] = {...} ?
> 
> 
> 
> 
> 
> ----- Original Message -----
>>  From: Jordi Gutiérrez Hermoso <address@hidden>
>>  To: address@hidden
>>  Cc: address@hidden
>>  Sent: Sunday, November 18, 2012 7:10 PM
>>  Subject: Re: equivalent for C-style init: structname varname[] = {...} ?
>> 
>>  On 18 November 2012 11:53, Dimitri Maziuk <address@hidden> 
> wrote:
>>>   On 11/17/2012 7:48 PM, Sergei Steshenko wrote:
>>> 
>>>>   In Octave structs are associative arrays.
>>> 
>>> 
>>>   Is that documented somewhere or is it lie the rest of octave 
>>  "documentation"
>>>   -- you're supposed to already know matlab?
>> 
>>  Octave structs are not associative arrays. Part of their
>>  implementation detail is that C++'s std::map is used to implement
>>  them, and this is casually mentioned in the manual. SS has latched on
>>  to this statement and concluded Octave is like Perl, or it's buggy
>>  because it's not like Perl.
>> 
>>  Octave's structs are supposed to look a lot more like C structs than
>>  like Python dictionaries or Perl hashes or PHP arrays.
>> 
>>>   Because it certainly explains why I can't have mixed-type fields 
> in a
>>>   struct.
>> 
>>  The fieldnames in a struct are subject to the same constraints that
>>  variable names are. In essence, they have to start with a letter, no
>>  spaces, and may only contain letters, numbers, and underscores.
>> 
>>  - Jordi G. H.
>>  _______________________________________________
>>  Help-octave mailing list
>>  address@hidden
>>  https://mailman.cae.wisc.edu/listinfo/help-octave
>> 
> 
> 
> "The fieldnames in a struct are subject to the same constraints that 
> variable names are" - no they are not:
> 
> octave:3> s = {}
> s = {}(0x0)
> octave:4> setfield(s, "foo bar", 123)
> ans =
> 
>   scalar structure containing the fields:
> 
>     foo bar =  123
> 
> octave:5>          
> .
> 
> And
> if you limited the fields to be just identifiers, you have introduced a
> show stopper bug because Octave is now deprived of normally working 
> associative arrays.
> 
> 
> Regards,
>   Sergei.
> _______________________________________________
> Help-octave mailing list
> address@hidden
> https://mailman.cae.wisc.edu/listinfo/help-octave


Furthermore, this is what 'doc struct' says:


"
...

   More realistically, all of the functions that operate on strings can
be used to build the correct field name before it is entered into the
data structure.

     names = ["Bill"; "Mary"; "John"];
     ages  = [37; 26; 31];
     for i = 1:rows (names)
       database.(names(i,:)) = ages(i);
     endfor
     database
          => database =
             {
               Bill =  37
               Mary =  26
               John =  31
             }
",

so, is Octave supposed to be limited to "Mary" and should not be able to use 
"Last dance with Mary Jane" ( 
http://www.metrolyrics.com/last-dance-with-mary-jane-lyrics-tom-petty.html ) ?

Regards,
  Sergei.






>