Re: [fpc-pascal] Managed record questions

> On Mar 9, 2018, at 11:19 PM, Sven Barth via fpc-pascal > wrote: > > Because this way the user is aware that they are something special and are > not supposed to be called manually. > That makes sense. Why can’t the compiler use a similar method to call

Re: [fpc-pascal] Managed record questions

Am 09.03.2018 16:41 schrieb "Ryan Joseph" : > On Mar 9, 2018, at 4:51 PM, Sven Barth via fpc-pascal < fpc-pascal@lists.freepascal.org> wrote: > > Objects share roughly as much code with records as classes do as internally classes and objects share most of their code.

Re: [fpc-pascal] Managed record questions

> On Mar 9, 2018, at 4:51 PM, Sven Barth via fpc-pascal > wrote: > > Objects share roughly as much code with records as classes do as internally > classes and objects share most of their code. > I’ll be curious what Maciej says about management operators

Re: [fpc-pascal] Managed record questions

> On Mar 9, 2018, at 4:13 PM, Ryan Joseph wrote: > > type > TDataObject = object > v: array[0..2] of integer; > end; > > procedure TestObjectCopy; > var > obj: TDataObject; > data: array[0..2] of integer; > i: integer; >

Re: [fpc-pascal] Managed record questions

Am 09.03.2018 10:14 schrieb "Ryan Joseph" : > >> 4) Move() on an object copies memory like a record (as a record does, so this is good). Does that mean they laid out in memory just like records? > > Yes, although I believe there is a hidden VMT field. Not sure how

Re: [fpc-pascal] Managed record questions

> On Mar 9, 2018, at 3:55 PM, Michael Van Canneyt > wrote: > > Hence my proposal to 'clean this up’. A good idea if they would be used. If objects had a couple minor things I personally could replace some records in certain parts of code and get real benefits.

Re: [fpc-pascal] Managed record questions

On Fri, 9 Mar 2018, Ryan Joseph wrote: On Mar 9, 2018, at 1:53 PM, Sven Barth via fpc-pascal wrote: They are broken, deprecated and essentially dead in Delphi, but in FPC we've always cared for them as well. Overloads and generics are already supported

Re: [fpc-pascal] Managed record questions

> On Mar 9, 2018, at 1:53 PM, Sven Barth via fpc-pascal > wrote: > > They are broken, deprecated and essentially dead in Delphi, but in FPC we've > always cared for them as well. > Overloads and generics are already supported and support for helpers could be

Re: [fpc-pascal] Managed record questions

Am 09.03.2018 05:14 schrieb "Ryan Joseph" : > On Mar 9, 2018, at 10:32 AM, Michael Van Canneyt wrote: > > Why don't you use objects ? No-one has obsoleted this, and you get what you > want: an object that can be allocated on the stack or on

Re: [fpc-pascal] Managed record questions

> On Mar 9, 2018, at 10:32 AM, Michael Van Canneyt > wrote: > > Why don't you use objects ? No-one has obsoleted this, and you get what you > want: an object that can be allocated on the stack or on the heap. Object is just for backwards compatibility right? Does it

Re: [fpc-pascal] Managed record questions

On Fri, 9 Mar 2018, Ryan Joseph wrote: On Mar 9, 2018, at 3:55 AM, Graeme Geldenhuys wrote: My first question What is a managed record? My second question Why would I need it? My third question. What is different compared to a

Re: [fpc-pascal] Managed record questions

> On Mar 9, 2018, at 3:55 AM, Graeme Geldenhuys > wrote: > > My first question > What is a managed record? > > My second question > Why would I need it? > > My third question. > What is different compared to a "normal record" > and

Re: [fpc-pascal] Managed record questions

On 2018-03-08 03:13, Ryan Joseph wrote: So in the trunk we have managed records now which is a brilliant addition and long overdue. Some questions these bring up: My first question What is a managed record? My second question Why would I need it? My third question.

Re: [fpc-pascal] Managed record questions

> On Mar 8, 2018, at 8:28 PM, Sven Barth via fpc-pascal > wrote: > > This is not an oversight, but an explicit design decision of the language. Do you recall what the history was of this choice? I can remember using the “new" keyword on objects but I don’t

Re: [fpc-pascal] Managed record questions

Am 08.03.2018 12:51 schrieb "Ryan Joseph" : > On Mar 8, 2018, at 5:42 PM, Sven Barth via fpc-pascal < fpc-pascal@lists.freepascal.org> wrote: > > You are supposed to use try...finally for this. The finally-block is always executed when the try-block is left no matter

Re: [fpc-pascal] Managed record questions

> On Mar 8, 2018, at 5:42 PM, Sven Barth via fpc-pascal > wrote: > > You are supposed to use try...finally for this. The finally-block is always > executed when the try-block is left no matter if it's by reaching the end, > calling exit or by an exception.

Re: [fpc-pascal] Managed record questions

Am 08.03.2018 09:44 schrieb "Ryan Joseph" : 2) We need to remember to call Free() at the end of the function and take precaution to not exit early and leak memory (maybe even using a goto to break out of nested loops or nested functions, who knows). You are supposed

Re: [fpc-pascal] Managed record questions

Am 08.03.2018 08:33 schrieb "Maciej Izak" : No, this doesn't beg the question, because Object Pascal classes are > designed in the principle to reduce on the heap. Changing this would not > only mean quite some changes in the compiler/RTL with no real gain, but it > would

Re: [fpc-pascal] Managed record questions

On 03/08/2018 10:16 AM, Ryan Joseph wrote: > > > > I know this is how it is and not likely to change I’m just pointing it out. In MSElang objects and classes have been unified, they can be allocated on stack or on heap. They also have hooks for initialization and finalization which can be used

Re: [fpc-pascal] Managed record questions

> On Mar 8, 2018, at 4:00 PM, Maciej Izak wrote: > > Small ad of mORMot (main author Arnaud Bouchez aka ab) : > > with SynCommons module you have nice utils for such things: > > procedure MyProc; > var > list: TList; > begin > with TAutoFree.One(list, TList.Create)

Re: [fpc-pascal] Managed record questions

2018-03-08 9:13 GMT+01:00 Ryan Joseph : > The more efficient approach would clearly be something like: > > procedure MyProc; > var > list: stack TList; // assume this allocates us on the stack like a > record > begin > list.Clear; // there’s no Create

Re: [fpc-pascal] Managed record questions

> On Mar 8, 2018, at 3:12 PM, Michael Van Canneyt > wrote: > > You can still use objects. I guess I can go back to objects and use pointers to objects when I want classes? I don’t know if objects even have all the same functionality of classes, and aren’t they for

Re: [fpc-pascal] Managed record questions

> On Mar 8, 2018, at 2:43 PM, Ryan Joseph wrote: > > In many cases I don’t actually need anything on the heap and a record could > be used instead but because of limitations on records in Pascal I need a full > class. Doing the ARC route is just solving a problem

Re: [fpc-pascal] Managed record questions

2018-03-08 9:12 GMT+01:00 Michael Van Canneyt : > You can still use objects. +1. in most of cases this is enough -- Best regards, Maciej Izak ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org

Re: [fpc-pascal] Managed record questions

> On Mar 8, 2018, at 2:20 PM, Maciej Izak wrote: > > Management operators are almost unusable without default field/default > property. How it works you can see here : > > https://github.com/maciej-izak/PascalSmartPointers > > the examples can be tested with NewPascal

Re: [fpc-pascal] Managed record questions

On Thu, 8 Mar 2018, Ryan Joseph wrote: On Mar 8, 2018, at 1:48 PM, Sven Barth via fpc-pascal wrote: You could use an include file containing both the declaration and implementation controlled by compiler defines together with a macro for the type name.

Re: [fpc-pascal] Managed record questions

> On Mar 8, 2018, at 1:48 PM, Sven Barth via fpc-pascal > wrote: > > You could use an include file containing both the declaration and > implementation controlled by compiler defines together with a macro for the > type name. That’s a nice trick. If those

Re: [fpc-pascal] Managed record questions

2018-03-08 7:48 GMT+01:00 Sven Barth via fpc-pascal < fpc-pascal@lists.freepascal.org>: > You could use an include file containing both the declaration and > implementation controlled by compiler defines together with a macro for the > type name. > Very improper and totally bad approach. This is

Re: [fpc-pascal] Managed record questions

2018-03-08 4:13 GMT+01:00 Ryan Joseph : > 1) Given the example below we have a template for a standard ref counted > record. Shouldn’t there be some “meta record” type that implements this > automatically? I’m thinking about adding this to some types but the idea of >

Re: [fpc-pascal] Managed record questions

Am 08.03.2018 04:44 schrieb "Ryan Joseph" : 1) Given the example below we have a template for a standard ref counted record. Shouldn’t there be some “meta record” type that implements this automatically? I’m thinking about adding this to some types but the idea of

[fpc-pascal] Managed record questions

So in the trunk we have managed records now which is a brilliant addition and long overdue. Some questions these bring up: 1) Given the example below we have a template for a standard ref counted record. Shouldn’t there be some “meta record” type that implements this automatically? I’m