Re: [PATCH] [IOS] Avoid spurious EOF when writing partial bytes

[Jose E. Marchesi]

>>    Using an EOF exception would be quite confusing for the user as
>>    well; if this is implemented, please use a more accurate exception
>>    (maybe a new one needs to be added)
>
> Yes, EOF is confusing.
>
> I think we really want to introduce an E_perm exception, and raise it in
> every peek* PVM instruction if the IO space doesn't support read.  Then
> a dump of a non-readable IO space, for example, would raise the
> exception instead of showing us an "empty" IO space.

As it happens this was also already in poke.rec:

Summary: Add IOS_EPERM and exception E_perm
Component: IO
Kind: ENH
Priority: 3
Description:
+ We need to incorporate an IOS_EPERM error code, to report cases where
+ we attempt to write to read-only IOS.
+
+ The peek*/poke* instructions in ``src/pvm.jitter`` shall raise E_perm
+ when they get IOS_EPERM.
+
+ Obviously a new exception ``E_perm`` shall be added as well.
Target: 2.0