the Hopwood design process

Claes Wikstrom <>
Tue Mar 14 09:39:29 CET 2006


David Hopwood wrote:
> Instances of features being
> *removed* from a programming language in the course of its incremental development
> are vanishingly rare. Partly this is because of backward compatibility, but
> mainly it is because the cost of retaining a feature is rather low.

I know of at least two language features/constructs that I implemented
for Erlang many years ago _and_ also removed them.
Thought I'd tell the list about them - just to tell you what
you all could have had.

- process migration

Bin = save_process(Pid),
RemotePid ! {newproc, Bin},


and then at the other end

receive
    {newproc, Bin} ->
       Pid = restore_process(Bin),




- nukeable arrays

T = {1,2,3,4,5,6},
T2 = nuke_element(3, T, newval),

Once T had been poked, any future read/write references
to T would render a badarg crash. The nuke_elem/3
BIF would destructively update the tuple and ensure that
the old value could never be used.



Both features - removed.


/klacke







-- 
Claes Wikstrom                        -- Caps lock is nowhere and
http://www.hyber.org                  -- everything is under control
cellphone: +46 70 2097763



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