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[Caml-list] productivity improvement
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| Date: | -- (:) |
| From: | John Max Skaller <skaller@o...> |
| Subject: | Re: [Caml-list] Array.resize ? |
Oleg wrote: >Hi > >Is there an efficient way in O'Caml to append an element to an array ref? > >let append_elt r x = r := Array.append !r [| x |];; > >copies the contents of the whole array in its body, while e.g. C++ vector >push_back in most cases won't (memory is reserved in chunks automatically, or >it can be reserved manually) > >IOW it seems strange to me that functions of arrays can change their contents >but not their size, while functions of array ref's can do it, but >inefficiently. How about > >Array.resize : 'a array -> int -> unit > >or at least > >Array.resize: 'a array ref -> int -> unit ? > I might add that I have requested a variable length array, similar to a C++ vector. It is possible to make one using pure Ocaml + a little Obj.magic. ** But it would be better if it were in the standard distribution. [you need allocate initialise unused slots using Obj.magic .. this is considered naughty :-] Similar for Strings .. though IMHO module String should be deprecated: we don't need Strings when we have Arrays. -- John Max Skaller, mailto:skaller@ozemail.com.au snail:10/1 Toxteth Rd, Glebe, NSW 2037, Australia. voice:61-2-9660-0850 ------------------- To unsubscribe, mail caml-list-request@inria.fr Archives: http://caml.inria.fr Bug reports: http://caml.inria.fr/bin/caml-bugs FAQ: http://caml.inria.fr/FAQ/ Beginner's list: http://groups.yahoo.com/group/ocaml_beginners