Dear Kevin,
Thanks for the responses! I will look into using the 'state' for the
iterator that can be later dereferenced. Indeed, one has to be careful
that the iterator could point to a data item that has been changed or
deleted. In C++, for each container operation there is a specification of
whether iterators are invalidated by the operation.
As for multiple ways to index, the example I have in mind is as follows: if
m is the associative map, (k,v) is a key-value pair, and i is an iterator
(the pointer kind, like in C++) to (k,v), then m[k] should return v, while
m[i] should return (k,v). But I am asking the forum whether a distinctive
syntax is available for the second variant.
Finally, with regard to the third issue, perhaps I didn't express my
question well. Suppose someone uses my 2-3 trees and has a statement in
his/her code such as
i = next(m,i)
where m is the map and i is an iterator (of the pointer kind). This
statement is supposed to advance to the next item according to the
sort-order of keys. My routine that gets invoked is as follows:
function nextloc{K,D}(t::BalancedTree{K,D}, i::Int)
if i == 2
error("Attempt to advance past end of balanced tree")
end
ii = i
p = t.data[i].parent
while true
newp, newii = nextloc0(t, p, ii)
if newii == 2 || t.data[newii].parent > 0
return newii
end
p, ii = newp, newii
end
end
Now, suppose instead the user writes:
@inbounds i = next(m,i)
Then I would want a different (faster, less safe) version of 'nextloc'
invoked. In the different version, the preliminary safety-test whether
i==2 is omitted, and the array subscript operations within my code are all
prefixed by @inbounds. So my question to the forum is whether my tree code
can detect whether the user has put an @inbounds declaration in his/her
code when it invokes my routines.
Thanks,
Steve
P.S. If you want to look at my code, please
see: https://www.dropbox.com/s/021yc196j55d5yd/baltree.jl This code is
very preliminary and has not even been executed, except for insert and
next. (See the test routine test2(), which seems to work.) The 'delete'
code is currently a hack, and I need to write a proper delete code that
shrinks the tree.
