[isabelle-dev] code abbreviation for mapping over a fixed range

[Florian Haftmann]

> The new definition actually causes *more* allocation than the original
> one, except for very short lists, because every call of @ copies its
> first argument. Note that the code equation for [_..<_] is
> 
>   lemma upt_rec[code]: "[i..<j] = (if i<j then i#[Suc i..<j] else [])"
> 
> which has no calls to @ at all; a corresponding code equation for
> a fused "map_upt f i j = map f [i..<j]" would be
> 
>   "map_upt f i j = if i < j then f i # map_upt f (Suc i) j else []"
> 
> which could be used to define map_range:
> 
>   "map_range f n = map_upt f 0 n"

OK, I'll revert this.

Thanks for having an eye on that.

	Florian

-- 

PGP available:
http://home.informatik.tu-muenchen.de/haftmann/pgp/florian_haftmann_at_informatik_tu_muenchen_de

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: OpenPGP digital signature
URL: <https://mailman46.in.tum.de/pipermail/isabelle-dev/attachments/20151112/c217cda5/attachment.sig>