From mboxrd@z Thu Jan 1 00:00:00 1970 Path: eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: "Randy Brukardt" Newsgroups: comp.lang.ada Subject: Re: String_Access in unbounded string handling? Date: Thu, 18 Jan 2024 19:36:59 -0600 Organization: A noiseless patient Spider Message-ID: References: Injection-Date: Fri, 19 Jan 2024 01:35:58 -0000 (UTC) Injection-Info: dont-email.me; posting-host="1a0b2567d4817eeafba9b9c082c79bc5"; logging-data="2979099"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/jGHALbdvrMq3e5pvh72FwzlrKJaDatf4=" Cancel-Lock: sha1:YR7abmySO+/CEqu63TLXox9Xt/o= X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.7246 X-RFC2646: Format=Flowed; Original X-Newsreader: Microsoft Outlook Express 6.00.2900.5931 X-MSMail-Priority: Normal X-Priority: 3 Xref: news.eternal-september.org comp.lang.ada:66013 List-Id: "Tucker Taft" wrote in message news:afd791fa-853f-48fa-9223-759b12d4ed87n@googlegroups.com... On Sunday, January 14, 2024 at 6:05:45?AM UTC-5, Blady wrote: >> Hello, >> >> String_Access is defined in A.4.5 Unbounded-Length String Handling: >> 7 type String_Access is access all String; >> >> and note: >> 75 The type String_Access provides a (nonprivate) access type for >> explicit processing of unbounded-length strings. >> >> I wonder what String_Access is for and what could be "explicit >> processing"? > >The idea was to support the explicit use of new String'(...), X.all, and >Unchecked_Deallocation >rather than the implicit use of the heap inherent in Unbounded strings. It >was recognized that you >need a single global access type to avoid having to do conversions all over >the place. This >predated the availability of stand-alone objects of an anonymous access >type >(aka "SAOOAAATs" ;-), but those are not universally loved either. It >certainly cannot be >removed now without potentially very painful disruption of existing users. >It could be moved >to a different package without too much disruption, but I haven't seen any >groundswell of interest >in doing that either. I'm dubious that there are any such users. Certainly, in the handful of cases where I needed such a type, I just declared it (strong typing, you know?) and never thought of Ada.Strings.Unbounded as being a place to find such a type already defined. It is such an odd place I doubt anyone outside of perhaps the people who defined the type ever used it. OTOH, I agree that the compatibility impact is non-zero (anyone who did use it would have to change their code), and the benefit of removing the type at this point is close to zero (junk declarations abound in long-term Ada packages, what's one more; and certainly there is a lot of unused stuff in any particular reusable package and any particular use), so the cost-benefit ratio doesn't seem to make a change here worth it. An Ada successor language would design Ada.Strings.Unbounded rather differently (so as to be able to use string literals directly with the type) and probably would include universal character support as well, so it's hard to find an important reason to change this. Also, I'm pretty sure we're discussed this within the ARG several times in the past, so this is well-trodden ground. Randy.