First Draft: Static Single Assignment

[Peter C]

On Sunday, 16 November 2025 at 03:12:08 UTC, monkyyy wrote:
> On Sunday, 16 November 2025 at 02:43:03 UTC, Richard (Rikki) 
> Andrew Cattermole wrote:
>> Three things I'd like to see here:
>>
>> 1. Function parameters
>>
>> 2. Fields
>>
>> 3. Globals
>
> ```d
> struct writeonce(T){
>   final T data;
>   final bool hasBeenSet;
>   auto opAssign(T data_){
>     assert( ! hasBeenSet);
>     return data=data_;
> }}
> ```
>
> ---
>
> `void foo(ref final int a)` it would need to be ref to do 
> anything

This use of 'final' .. me no like!

Seeing 'final' makes me immediately think about inheritance and 
method overriding.

That extra disambiguation required here, increases my cognitive 
load - which me also no like!

Just the use of this overloaded term 'final' turns me off any 
proposal that wants to use it - yet again!

An explicit keyword that communicates directly one thing, and one 
thing only - "assign once during construction", will make the 
code's meaning both immediate and unambiguous.

Keywords should communicate intent directly.

I propose intead, 'init' -  it (at least to me) directly evokes 
an initialization context for the construction of a variable.

This is not bikeshedding. It's not trivial nitpicking. Choosing 
the right primitive here needs to be a well thought out design 
decision.

'final' would almost certainly negatively affect cognitive load, 
and the programmers ability to quickly reason about code - not to 
mention 3rd party tools.

Any proposal using that overloaded term 'final' will get the 
thumbs down from me.