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Re: Overwrite Data
Posted: Tue Oct 14, 2014 3:24 am
by Positive07
Yeah that is exactly what deepCopy does, your simpler shallow copy does the following
Code: Select all
t = {
a = {
b = "hello"
}
}
for k,v in pairs(t) do
x[k] = t[k]
end
x.a.b = "bye"
print(t.a.b) --"bye"
print(t==x) --"false"
print(t.a == x.a) --"true"
while deep copy
Code: Select all
t = {
a = {
b = "hello"
}
}
x = deepCopy(t)
x.a.b = "bye"
print(t.a.b) --"hello"
print(t == x) --"false"
print (t.a == x.a) --"false"
I think that Robins code breaks when you do this though:
Since it can't handle table loops, if you wanted to do this you would first have to detect the loops with parsing... and that is really hard... maybe there is a library to do this
Re: Overwrite Data
Posted: Tue Oct 14, 2014 4:42 am
by khamarr3524
Right well, it should suffice for my usage. The data files for Units are static and formatted by hand. Nothing strange should be going on in there. I will simply use a recursion method. I'll do something like
Code: Select all
function copyTable(t)
local tbl = {}
for k, v in pairs(t) do
if type(v) == "table" then
tbl[k] = copyTable(v)
end
tbl[k] = v
end
return tbl
end
I'm assuming this would work just fine?
Re: Overwrite Data
Posted: Tue Oct 14, 2014 5:02 am
by Positive07
Yeah indeed, it is really similar to deep copy
Re: Overwrite Data
Posted: Tue Oct 14, 2014 5:35 am
by ivan
Minor bug:
Code: Select all
if type(v) == "table" then
tbl[k] = copyTable(v)
end
tbl[k] = v -- overwrites the copied table reference
Should probably be
Code: Select all
if type(v) == "table" then
tbl[k] = copyTable(v)
else
tbl[k] = v
end
Re: Overwrite Data
Posted: Tue Oct 14, 2014 10:36 am
by Robin
Positive07 wrote:
I think that Robins code breaks when you do this though:
Since it can't handle table loops,
Actually, that's exactly the sort of thing my code fixed, compared to some more naive attempts at deep copying.
(Also, that should really be something like
t = {}; t.a = t, but yeah.)