Right now I am trying to rewrite my wrapper for VapourSynth:
* old: [VapourSynth.nim](https://github.com/mantielero/VapourSynth.nim)
* new: [vs.nim](https://github.com/mantielero/vs.nim) (futhark based, by the
way)
The old one was moving pointers. Now I am trying to move objects that contain a
handler with the pointer.
So in the old API I had:
proc len*(vsmap:ptr VSMap, key:cstring):int =
Run
while in the new API:
type
VSMapObj* = object
handle*:ptr VSMap
proc `=destroy`*(self: VSMapObj) =
if not self.handle.isNil:
api.handle.freeMap(self.handle) # this is from the C API
...
proc len*(vsmap:VSMapObj; key:string):int =
Run
Now I am facing some memory issues, probably due to my bad understanding of the
topic. When I compile
[ex06_adding.nim](https://github.com/mantielero/vs.nim/blob/79955f33f1f928ff84de98acb2354eeefbb1e493/tests/ex06_adding.nim#L7)
it works fine, but then after the execution it tries to destroy an `VSCoreObj`
instance which uses the same approach as above. I get the error:
false
200 frames written to 'demo.y4m'
[INFO] destroying VSCoreObj instance
Traceback (most recent call last)
/home/jose/src/nimlang/vs.nim/src/lib/libcore.nim(17) ex06_adding
/home/jose/src/nimlang/vs.nim/src/lib/libcore.nim(21) =destroy
SIGSEGV: Illegal storage access. (Attempt to read from nil?)
Error: execution of an external program failed:
'/home/jose/src/nimlang/vs.nim/tests/ex06_adding'
Run
The issue is in [this
line](https://github.com/mantielero/vs.nim/blob/79955f33f1f928ff84de98acb2354eeefbb1e493/src/lib/libcore.nim#L21),
but I don't get it. One `VSCoreObj` instance is needed and I create it
[here](https://github.com/mantielero/vs.nim/blob/79955f33f1f928ff84de98acb2354eeefbb1e493/src/lib/helper.nim#L5)
for the whole execution. It looks like `=destroy' is called only once since
the `[INFO] destroying VSCoreObj instance` line only appears once.
Do you see any obvious error?
