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[Caml-list] productivity improvement
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Date: 2002-07-11 (23:00)
From: Alessandro Baretta <alex@b...>
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)

Ah, wait a minute. A vector is not an arraw. Whatever its 
implementation it only behaves like an array from a 
syntactic point of view: it defines the operator[] for array 
indexing, but it might as well be implemented as a list for 
all you know; however, the STL imposes constraints on the 
complexity of the different algorithms used to manage a 
vector. I have found the following definition of a vector:
 > A vector is a Sequence that supports random access to
 > elements, constant time insertion and removal of elements
 > at the end, and linear time insertion and removal of
 > elements at the beginning or in the middle. The number of
 > elements in a vector may vary dynamically; memory
 > management is automatic.

This is much different from either a C array or an O'Caml 
array. Again, the issue is raised: do we need an OCaSTL?


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