Feature announcement: Function References and Anonymous Functions

[munair]

  for I := 0 to function: integer
  begin
    if StrLen < TypeBits then Result := StrLen
    else
      Result := TypeBits;
  end() - 1 do

It made me actually quite curious, but the SharpBASIC compiler supports this construct, because the parser expects expressions, which functions are a part of. I never tried it before. It outputs 0..9:

Code: Text  [Select][+][-]

1. ' SharpBASIC for-loop with functions
2. ' ----------------------------------
3. incl "lib/sys.sbi";
4.  
5. decl func f1():int;
6. decl func f2():int;
7.  
8. dim i:itr;
9.  
10. main do
11.   for i = f1() to f2() :++ do
12.     print(i);
13.   end
14.   print();
15. end
16.  
17. func f1():int do f1 = 0; end
18. func f2():int do f2 = 9; end
19.  

But it needs a valid function reference. The keyword func or function alone is of course not enough.

[PascalDragon]

That won't work.(I hope... )
Loop variables need to be known at compile time.

That does work, after all its only calling a function (no matter how bad it looks). The ranges of the loop don't need to be known at compile time (cause otherwise any for i := 0 to SomeList.Count do-loop would not work). The important point is that the ranges are only evaluated once and that is guaranteed by the code that the compiler generates.

fpc4.0  release time ？

Considering that it's not even clear whether the next major release will be 3.4 or 4.0 I'd say 4.0 will be released at least in this century. 🤷‍♀️

[Bart]

... I'd say 4.0 will be released at least in this century. 🤷‍♀️

Are you sure?

Bart

[PascalDragon]

... I'd say 4.0 will be released at least in this century. 🤷‍♀️

Are you sure?

I'm an optimist, so I'm at least confident 😅

[d2010]

Dear Free Pascal Community,

The Free Pascal Developer team is pleased to finally announce the addition of a long awaited feature, though to be precise it's two different, but very much related features: Function References and Anonymous Functions. These two features can be used independantly of each other, but their greatest power they unfold when used together.

Why You using  same syntax, perhaps overflow-up too much the tokenizer?
I think you replace "procedure" with "procedure.ref"
      function with funct.ref
You cannot use
You must quote name of procedure  with other chars, diferent  '' ' ' ' ' ''
  F"nop"   double 0quotes ""
The type string of too good, and you

 

Code: [Select]

  p := procedure(begin.ref,Writeln('Foobar'),end)
  p();


Code: Pascal  [Select][+][-]

1. type
2.   TFunc = function: LongInt;
3.  
4. var
5.   p: TProcedure;
6.   f: TFunc;
7.   n: TNotifyEvent;
8. begin
9.   procedure("Nop",const aArg: String)
10.   begin
11.     Writeln(aArg);
12.   end('Hello World');
13.  
14.   p := procedure("Nop",Writeln('Foobar');end;
15.   p();
16.   n := procedure("Nop",aSender: TObject);
17.        begin
18.              Writeln(HexStr(Pointer(aSender));
19.            end;
20.   n(Nil);
21.  
22.   f := function("MyRes" : LongInt;
23.        begin
24.              "MyRes" := 42;
25.            end;
26.   Writeln(f());
27. end.

 
         Old codes , previous here --

Code: Pascal  [Select][+][-]

1. type
2.   TFunc = function: LongInt;
3.  
4. var
5.   p: TProcedure;
6.   f: TFunc;
7.   n: TNotifyEvent;
8. begin
9.   procedure(const aArg: String)
10.   begin
11.     Writeln(aArg);
12.   end('Hello World');
13.  
14.   p := procedure
15.        begin
16.              Writeln('Foobar');
17.            end;
18.   p();
19.  
20.   n := procedure(aSender: TObject);
21.        begin
22.              Writeln(HexStr(Pointer(aSender));
23.            end;
24.   n(Nil);
25.  
26.   f := function(MyRes : LongInt;
27.        begin
28.              MyRes := 42;
29.            end;
30.   Writeln(f());
31. end.

[Thaddy]

The syntax is delphi compatible.

[PascalDragon]

Why You using  same syntax, perhaps overflow-up too much the tokenizer?

This feature is intended to be Delphi-compatible, thus the Delphi-compatible syntax is used. It makes no sense to invent a different syntax when we need the Delphi-compatible one anyway. Nothing more, nothing less.

[cocce]

Do you know when it will be released?
Thanks in advance.

[PascalDragon]

Do you know when it will be released?

No.

[Thaddy]

If you do not use FreePascal in any professional capacity, but only as a semi-professional or a hobbyist, why don't you simply use trunk?
I think that most users that call for a release that contains  certain new features really do not need a "release" for that.

[PascalDragon]

有点慢

Please only use English in the international part of the forum or provide a translation with your post.

[vfclists]

If you do not use FreePascal in any professional capacity, but only as a semi-professional or a hobbyist, why don't you simply use trunk?
I think that most users that call for a release that contains  certain new features really do not need a "release" for that.

Is trunk good enough and safe enough for the current Lazarus 4.xx? Are enough users happy with it?

The comments in this thread don't reassure me Status of FPC 3.4.0 or FPC 4.0.0 [major release]

[Thaddy]

About 30-40% use trunk. For all intend and purpose it feels stable but there are many open bugs of differing urgency. Most people won't even notice any bugs.

[440bx]

Most people won't even notice any bugs.

That alone is an indication of a significant problem.

I cannot even port the Windows API definitions without running into FPC bugs and deficiencies.    IOW, it doesn't even take writing code to run into problems, just declarations/definitions does it.

How about that for a "new feature" ?... being able to faithfully and correctly port the Windows API from C to FPC.  Personally, I think that would be a great "new feature" (and a rather useful one too.)

[ALLIGATOR]

I just want to note that FPC 3.2.2 and 3.2.4 also have bugs, just like FPC[main]

And it's still a big question where there are more of them