"Joel de Guzman" <djowel@[...].uk>  writes:

>  Raoul Gough <RaoulGough@[...].uk> wrote:
> > "Joel de Guzman" <djowel@[...].uk> writes:
> > 
> >> Mike Thompson <mike.thompson@[...].au> wrote:
> > [snip]
> >>> The IndexError arises because vector_indexing_suite defends against
> >>> an slice index being too big, rather than the python list approach
> >>> which regards a slice index > len(L) as equal to len(L).  So, the
> >>> line of padOrChop() which says:
> >>> 
> >>>     lst[size:] = [padValue] * diff
> >>> 
> >>> causes an exception when size > len(lst).
> >>> 
> >>> Should vector_indexing_suite be altered to give behaviour more like
> >>> that of lists in this regard?
> >> 
> >> It should. I think you uncovered a vector_indexing_suite bug. I'll
> >> correct this as soon as I can.
> > 
> > Hi Joel,
> > 
> > You might find the PySlice_GetIndices function useful - it take a
> > Python slice object and a container length and returns normalized
> > start and stop values (even handling negative indices, IIRC). At a
> > guess, this is probably how the Python list works internally too.
> 
>  I *was* using PySlice_GetIndices. The problem was (if I'm not mistaken),
>  is that it does not handle non-integer inteces. Correct me if I'm wrong.
>  For example, I have a case where the indexes are dates that I must convert
>  to a valid index.

Well, it only works for slices, which (AFAIK) rules out non-integer
values anyway. I'm confused now about what the original problem was,
because I think using PySlice_GetIndices would already rule out any
problems with lst[99999:] and so on. Problems with lst[99999]
(i.e. not a slice) are a different matter, and even Python lists barf
on indexes out of range here.

-- 
Raoul Gough.
(setq dabbrev-case-fold-search nil)


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