Re: Thinner type checks: use error instead of assert

[Sam S. <sd...@gn...>]

> * Bruno Haible <oe...@py...t> [2004-07-22 22:51:28 +0200]:
>
>> > Thinner type checks: use error instead of assert.
>>
>> this makes error recovery harder.
>> why?
>
> assert was taking more than 100 bytes of bytecode in _each_ slot accessor
> method. Just wasted space.
>
> I don't think error recovery at the lowest level is important. Example:
>
>   (defun matrix-multiply (x y)
>     (with-slots (x11 x12 x21 x22) x .....))
>
> If the users passes a wrong object instead of a matrix, will he want
> to acknowledge 4 errors, and continue from each of them by passing a
> replacement object? No, he will want to replace the 'x' just once and
> then 'redo' the matrix-multiply invocation stack frame.

the first assert should affect all: the replacement value should
propagate.   maybe WITH-SLOTS should push the check to the beginning
and then use accessors with check stripped.

> So I consider it much more important to work on a general 'redo'/'return'
> facility than on low-level continue everywhere.
> For example using your approach from 2004-04-21.

are you working on that?

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