Re: need help learning Ada for a modula-2 programmer

[agent@drrob1.com]

On Tue, 28 Jan 2014 12:18:33 GMT, Brian Drummond
<brian3@shapes.demon.co.uk> wrote:

>The specific errors have been addressed by others, but as a former M2 fan 
>who has transitioned to Ada, I have a suggestion to help with this last 
>point...
>
>Ada allows variable sized arrays (including strings) to be allocated on 
>the stack - PROVIDED the actual runtime size is known at the point of 
>allocation. 
>
>It also allows the size (or first and last indices) of an array to be 
>queried at runtime.
>
>It also allows new declaration regions within blocks of code (funnily 
>enough, beginning with the word "declare"...)
>
>Put together, these can greatly reduce the pain of processing with fixed 
>length strings, so that actually using variable length strings is rarer 
>than you might imagine at first sight.
>
>So for example you can write MDY2STR as a function:
>

Brian, I need more help here.  I have another function I am trying to
get working, that you may recognize from M2 code

PROCEDURE GetCommandLine(CommandLine : OUT String) is
BEGIN
  n := argument_count;
  k := 1;

  WHILE k <= n LOOP
    move(argument(k),argstr);   -  tried this-
    argstr := argument(k);         -- and this.  Neither works.

    cmdlinefrag := cmdlinefrag & argstr;
    cmdlinefrag := cmdlinefrag & ' ';
    k := Natural'SUCC(k);
  END LOOP; -- while k < n
  CommandLine := cmdlinefrag;
END GetCommandLine;

I am getting "wrong lengty for array of type string" errors.

I was able to get this code working using variable length strings.  I
used bounded strings by copying the code from the texttools.common
routines.

I don't understand how to get this working using standard strings.
This is easy for me using ARRAY OF CHARACTER types in M2 and
procedures from the Strings standard module.

Thanks again for your help.