[Oberon] Dynamically sized allocation with NEW()

[Tomas Kral]

On Mon, 14 Jan 2019 22:34:03 +0100
Andreas Pirklbauer <andreas_pirklbauer at yahoo.com> wrote:

> NEW(F.raster, NofBytes);

Hi, very interesting.
Is this allocated on the heap, or stack?

I am also interested in the other world without dynamic allocation,
i.e. NEW(p);

Can we also toy with some allocation templates
based on NEW(p);

MODULE Heap;
  IMPORT S := SYSTEM;

  TYPE
    Size = INTEGER;
    Block = INTEGER;

    Buf16 = POINTER TO S16;
    Buf32 = POINTER TO S32;
    Buf64 = POINTER TO S64;
    Buf128 = POINTER TO S128;
    Buf256 = POINTER TO S256;
    Buf512 = POINTER TO S512;
    Buf1024 = POINTER TO S1024;
    
    S16 = RECORD s: ARRAY 16 OF BYTE END ;
    S32 = RECORD s: ARRAY 32 OF BYTE END ;
    S64 = RECORD s: ARRAY 64 OF BYTE END ;
    S128 = RECORD s: ARRAY 128 OF BYTE END ;
    S256 = RECORD s: ARRAY 256 OF BYTE END ;
    S512 = RECORD s: ARRAY 512 OF BYTE END ;
    S1024 = RECORD s: ARRAY 1024 OF BYTE END ;
  
  VAR buf16: Buf16; ... buf1024: Buf104;

  PROCEDURE Alloc*(sz: Size; VAR b: Block)
  BEGIN
    IF sz < 16 THEN NEW(Buf16); b := S.VAL(Block, Buf16)
    ELSIF sz < 32 THEN NEW(Buf32); b := S.VAL(Block, Buf32)
    ...
    ELSIF sz < 1024 THEN NEW(Buf1024); b := S.VAL(Block, Buf1024)
    ELSE b := NIL
    END
  END Alloc;

END Heap;

-- 
Tomas Kral <thomas.kral at email.cz>