Re: What do you think about this?

[Laurent <lutgenl@icloud.com>]

On Tuesday, 23 June 2015 22:20:37 UTC+2, Anh Vo  wrote:

> I would suggest to improve the last two functions with the following preconditions. That means any attempt to pass an String whose length is longer than 40 characters will be slapped by the run time.
> 
>    --...
>    with pre => Right <= V_String_Length;
> 
> Anh Vo

You mean like this? Sry no idea on how to use pre/post conditions.

   function "+" (Right : String) return V_String.Bounded_String
   is (V_String.To_Bounded_String (Right))
   with pre => Right <= V_String_Length;

This doesn't compile. 

Builder results
    /Volumes/Kingston/GPS/Generateur_Trame_Vitek/common_defs_bci.ads
        16:16 expected type universal integer
        16:16 found type "Standard.String"

Either it is normal or I put the with... at the wrong place.

If I change to with pre => V_String.Length(V_String.To_Bounded_String(Right)) <=V_String_Length;
than it compiles but I don't see a difference in behavior. If I try to convert a string longer than max_lenght of V_String then my program dies with raised ADA.STRINGS.LENGTH_ERROR : a-strsup.adb:1926. That happens without the precondition but also with it?

The switch -gnata is enabled (found in the ada gems? that is required for the evaluation of the Pre/post conditions).

Thanks

Laurent