does `copy` work? although `bytestring` also seems like a good method for
this also. it seems wrong to me also that `match` is making a copy of the
original string (if that is indeed what it is doing)
On Tue, Jul 21, 2015 at 6:57 PM andrew cooke <and...@acooke.org> wrote:
>
> string(bytestring(...)) seems to do it. would appreciate any more
> efficient solutions (and confirmation the analysis is correct - is this
> worth filing as an issue?)
>
>
> On Tuesday, 21 July 2015 19:33:05 UTC-3, andrew cooke wrote:
>>
>>
>> well, this was fun... the following code rapidly triggers the OOM killer
>> on my machine (julia 0.4 trunk):
>>
>> s = repeat("a", 1000000)
>> l = Any[]
>> r = r"^\w"
>>
>> for i in 1:length(s)
>> m = match(r, s[i:end])
>> push!(l, m.match)
>> end
>>
>> note that: (1) the regexp is only matching one character, so the array l
>> is at most a million characters long.
>>
>> what i think is happening (but this is only a guess) is that s[i:end] is
>> being passed though to the c level regexp library as a new string. the
>> result (m.match) is then a substring into that. because the substring is
>> kept around, the backing string cannot be collected. and so there's an n^2
>> memory use.
>>
>> ideally, i don't think a new copy of the string should be passed to the
>> regexp engine. maybe i am wrong?
>>
>> anyway, for now, if the above is right, i need some way to copy m.match.
>> as far as i can tell string() doesn't help. so what works? or am i wrong?
>>
>> thanks,
>> andrew
>>
>
