Re: Unconstrained arrays

[dst17!mab@ford-wdl1.arpa (Mark A Biggar)]

In article <9308111528.aa04642@Paris.ics.uci.edu> kanderso@mabillon.ICS.UCI.EDU
 (Kenneth Anderson) writes:
>  I have declared the following type (DynamicString is an imported type)
>        type Str_Array is array (Natural range <>) of DynamicString;
>Later when I try to declare objects of this type, the compiler likes this
>   Viewers : str_array(1 .. 6) := (Create("Airspeed_Guage"),
>                                   Create("Altimeter_Guage"),
>                                   Create("Compass_Guage"),
>                                   Create("Horizon_Guage"),
>                                   Create("ROC_Guage"),
>                                   Create("Turn_Guage"));
>but it does not like this
>   Viewers : str_array(1 .. 1) := (Create("text_artist"));
>Here is the error message generated by the SunAda 1.1 compiler
>--### A:error: RM 8.3: no visible identifier is of type str_array
>If I change the above declaration to
>   Viewers : str_array(1 .. 2) := (Create("text_artist"),
>                                   Create("ignore"));
>The compiler is happy again.

I think that one of your problems is that the error message is very
missleading.  You real problem is that you can't use positional notation
for single element aggregates.  The compiler can't tell the difference
between a single element positional aggregate and a simple expression with an
extra set of enclosing parens.  So convert your aggregate to named notation
like so:

    Viewers : str_array(1..1) := (1 => Create("text_artist"));

and that should fix your problem.
And, if you really want to make sure that the complier excepts and also
document what is really going on, use a qualified expression for the
initializer like so:

   Viewers : str_array(1..1) := str_array'(1 => Create("text_artist"));

--
Mark Biggar
mab@wdl.loral.com