Re: Textedit and txt

[brbarkstrom@gmail.com]

On Thursday, May 7, 2015 at 5:12:29 PM UTC-4, Laurent wrote:
> On Wednesday, May 6, 2015 at 11:23:36 PM UTC+2, Randy Brukardt wrote:
> 
> Hi
> 
> I tried to put that package together but I get this error on the second function:
> 
>         14:4 no visible subprogram matches the specification for "+"
>         14:4 missing specification for "Drop"
> 
> 
> with Ada.Strings.Bounded;
> 
> package Common_Defs is
> 
>    V_String_Length  : constant :=  256;
> 
>    package V_String is new
>      Ada.Strings.Bounded.Generic_Bounded_Length (V_String_Length);
> 
>    function "+" (Right : V_String.Bounded_String) return String
>    renames
>      V_String.To_String;
> 
>    function "+" (Right : String) return V_String.Bounded_String
>    ^----- error
>    renames
>      V_String.To_Bounded_String;
> 
> end Common_Defs;
> 
> I have no idea what the compiler is complaining about.
> 
> > Note that some people hate using "+" this way, because they think it has 
> > something to do with numerics. We really should have something non-specific 
> > (say an operator "#"), but the ARG is always split between people that think 
> > we already have such an operator ("+") and thus we don't need another one 
> > and those that are repulsed by using "+" this way. (Getting these put into 
> > the packages themselves failed for similar reasons. Grumble.)
> 
> Well if it makes life easier why not use it. And if someone does't like to use a '+' then take something else, as long as you remember what it is doing.
> 
> >I'd prefer a completely different design for both of these packages, so we could add some >mechanism to allow direct conversions, but that's likely too radical.) 
> 
> Why would that be too radical?
> 
> Thanks
> 
> Laurent

Sorry to go back in the thread.  However, instead of creating a new
symbol '+' to indicate append, it might be easier to consult the Ada
RM.  In section A.4.4 of the Ada 2012 RM, there are a number of overloaded
functions specifically called 'Append'.  Furthermore, the second page of this 
section specifically uses '&' as an append operator.  Since these two 
constructions are already part of the package `Bounded_String', it isn't clear 
what we gain by using a variant construction.

Bruce B.