On 4/12/11 2:24 PM, Jonas Sicking wrote:
Hi All,
It was recently (yesterday) pointed out to me that we let a bad
spec-bug slip through for File.slice. It doesn't match the argument
semantics of Array.slice which can be very confusing for developers.
In Array.slice the second argument is the index of the last item to be
included in the returned slice.
In File.slice the second argument is the number of bytes included in
the returned slices.
In other words, it's Array.slice(start, end), but File.slice(start, length).
Additionally, in Array.slice the second argument is optional.
File.slice is currently shipped by Chrome and Firefox 4. I would be
fine with fixing this in Firefox 4.0.1, however that only makes sense
if the chrome folks are fine with fixing it in their implementation.
So consider this an official request, would chrome be ok with changing
the spec here?
/ Jonas
I'm bummed that we collectively let this slip through the cracks, and
personally think it's early enough to fix it. But we should also decide
how closely to match Array.slice. Should we allow code of the sort
file.slice(-80)?
Code of that sort is allowed with Array.slice.
MDC has good developer docs about what's in Firefox for Array.slice:
https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/slice
Developers may have already discovered file.slice (e.g. see
http://hacks.mozilla.org/2011/04/resumeupload/), so fixing this will
involve some messaging.
-- A*
