Pointer syntax in ARM BASIC?

There was a post over on Stardot https://stardot.org.uk/forums/viewtopic.php?f=63&t=20182 concerning adding fucntionality into BBC BASIC for SDL, to allow a “built-in way of assigning a memory address to a structure” (BBC BASIC for SDL supports a structure syntax)

This got me wondering if other than indirection operators there was ever a pointer syntax considered for ARM BASIC?

This got me wondering if […] there was ever a pointer syntax considered for ARM BASIC?

Considered, yes, implemented, no. Basalt has the PTR object function, which is very similar to BB4W’s '^'. You may notice that Richard now uses PTR for his SDL version, which possibly arises from our discussions about this a while back. ;-)

a “built-in way of assigning a memory address to a structure”

Basalt implements structures in a different way to BB4W and Richard’s ongoing versions. It has always allowed a structure to be applied to an existing block of memory, eg:

prototype=DEF(STRUCT OF integer%,string$,float|)
structure=NEW(prototype TO block%)

This can be used to access a window block, so you could have:

Window=DEF(STRUCT OF  
 handle%,visible{Rectangle},scroll{Vector},behind%,window#(31),
 colours?(7),workarea{Rectangle},title#(31),button%,sprites%,minimum%,
 title$[11],icons%,icon(20){Icon})
SYS "Wimp_GetWindowInfo",,window%
window=NEW(Window TO window%)
PRINT \window.icon(3).text$

Edit: This does expect the structures Rectangle, Vector, Icon are already defined.

The approach in “BBC BASIC for SDL” is noted here:-

https://stardot.org.uk/forums/viewtopic.php?f=63&t=19798&start=120#p287985

(Also- https://groups.io/g/bb4w/topic/76065935#23449)

Is there a mechanism for suggesting ARM BASIC in Risc OS Open adopts an equivalent approach?

Having a “pointer” syntax in ARM BASIC alongside the current indirection operators would aid code readability.
(Aside: having pointers AND structures in ARM BASIC would greatly simplify some SYS call setups from ARM BASIC.)

Is there a mechanism for suggesting ARM BASIC in Risc OS Open adopts an equivalent approach?

Any changes are constrained in much the same way Richard is constrained with BB4W. He has a free-er hand with the SDL versions, I think.

Having a “pointer” syntax in ARM BASIC alongside the current indirection operators would aid code readability.

Yes, which is why Basalt has PTR. However, I now realise it is different to the way Richard has implemented it. Mine returns the descriptor, as does '^', but there is PTR! which does more or less the same as Richard’s. ;-)

having pointers AND structures in ARM BASIC would greatly simplify some SYS call setups from ARM BASIC

I entirely agree. In my example above you would pass a window block to a SWI as PTR!(window), that is if it is a new structure. ;-)

I seem to recall some SWI’s accept a pointer as R0 or R1, as opposed to having to setup an entire sequence of registers?

Many SWIs accept/return pointers – window manipulation, poll blocks, reading the time, listing what files are in a directory……