> > > here's the crash now:
> > >
> > > Traceback (most recent call last):
> > > File 
> > > "/nix/store/f2krmq3iv5nibcvn4rw7nrnrciqprdkh-python3-3.12.9/lib/python3.12/pdb.py",
> > > line 1960, in main
> > >     pdb._run(target)
> > >   File 
> > > "/nix/store/f2krmq3iv5nibcvn4rw7nrnrciqprdkh-python3-3.12.9/lib/python3.12/pdb.py",
> > > line 1754, in _run
> > >     self.run(target.code)
> > >   File 
> > > "/nix/store/f2krmq3iv5nibcvn4rw7nrnrciqprdkh-python3-3.12.9/lib/python3.12/bdb.py",
> > > line 627, in run
> > >     exec(cmd, globals, locals)
> > >   File "/home/karl3/projects/rep/rep/dict.py", line 394, in <module>
> > >     doc.update([[val,val]])
> > >   File "/home/karl3/projects/rep/rep/dict.py", line 349, in update
> > >     super().update(keyhashitems())
> > >   File "/home/karl3/projects/rep/rep/dict.py", line 164, in update
> > >     assert int.from_bytes(keyhash[:hashbytes], 'big') >> hashshift == 
> > > newidx
> > >            
> > > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > > AssertionError
> > >
> > >
> > >
> > >         for keyhash, item in keyhashitems:
> > >
> > >                                                           assert item
> > > != self._sentinel
> > >
> > >                                   byteidx =
> > > int.from_bytes(keyhash[:hashbytes], 'big')
> > >
> > >                                     newidx = byteidx >> hashshift
> > >
> > >
> > >            if self._capacity > 0:
> > >
> > >                                                              # this
> > > block checks for collision with previous stored values
> > >
> > >                                        if capacity > self._capacity:
> > >
> > >
> > >                   superidx = int.from_bytes(keyhash[:self._hashbytes],
> > > 'big') >> self._hashshift
> > >                                                             else:
> > >
> > >
> > >                                        superidx = newidx
> > >
> > >
> > >           place = self.array[superidx]
> > >
> > >                                                         if place !=
> > > self._sentinel:
> > >
> > >                                       collision = self._key(place)
> > >
> > >
> > >              if collision != keyhash:
> > >
> > >                                                                assert
> > > superidx == int.from_bytes(collision[:self._hashbytes], 'big') >>
> > > self._hashshift
> > >                                             updates[newidx] =
> > > [collision, place, False]
> > >
> > >                 # this separated approach to checking for collisions
> > > allows for accepting
> > >                                                                 #
> > > batched data that ends up containing hash collisions solely within
> > > itself
> > >                                                 placing =
> > > updates.get(newidx)
> > >             if placing is not None:
> > >                 collision, place, is_new = placing
> > >                 while newidx == int.from_bytes(collision[:hashbytes],
> > > 'big') >> hashshift:
> > >                     capacity <<= 1
> > >                     expansion <<= 1
> > >                     #spread += 1
> > >                     #hashbits = self._hashbits + spread
> > >                     hashbits += 1
> > >                     hashbytes = (hashbits+7) >> 3
> > >                     hashshift = (hashbytes << 3) - hashbits
> > >                     byteidx = int.from_bytes(keyhash[:hashbytes], 'big')
> > >                     newidx = byteidx >> hashshift
> > >                     assert capacity == (1 << hashbits)
> > >                 new_updates = {}
> > >                 for keyhash, item, is_new in updates.values():
> > >                     if is_new:
> > >                         newnewidx =
> > > int.from_bytes(keyhash[:hashbytes], 'big') >> hashshift
> > >                         assert newnewidx not in new_updates
> > >                         new_updates[newnewidx] = [keyhash, item, True]
> > >
> > >                                                               updates
> > > = new_updates
> > >             assert newidx not in updates
> > >             assert int.from_bytes(keyhash[:hashbytes], 'big') >>
> > > hashshift == newidx
> > >             updates[newidx] = [keyhash, item, True]
> > >
> > >
> > > it looks like the problem is that keyhash is shadowed in the loop at the 
> > > end :D
>
> shadowing is when a variable is used in an inner scope with the same
> name as an outer scope. many languages have strictly scoped blocks but
> python is not one of those languages allowing occasional mistakes like
> this. keyhash is used in an outer scope. i then use it as a loop
> variable, which changes its value in the outer scope.

gotta acknowledge here that the source paste is illegible because of
all the wrapping and whitespace !

also, how is this like use of the word "shadow" in corruption? the
people causing the corruption are (a) _hidden_ like the old value of
the variable, where people see the one that is presented rather than
the one acted and (b) cause _wrong events_ like the new value of the
variable overridding its correct one

>
> usually a shadowed variable would make the opposite crash -- where in
> the inner loop, the inner value is used as if it were the outer. here,
> since it's python, the crash is from the outer value being used after
> the inner loop has finished. [...
>
> >
> > now i've got this:
> >   File "/home/karl3/projects/rep/rep/dict.py", line 220, in 
> > content_generator
> >     assert superidx * expansion + subidx ==
> > int.from_bytes(dbg_keyhash[:hashbytes], 'big') >> hashshift
> >            
> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > AssertionError
> > Uncaught exception. Entering post mortem debugging
> > Running 'cont' or 'step' will restart the program
> > > /home/karl3/projects/rep/rep/dict.py(220)content_generator()
> > -> assert superidx * expansion + subidx ==
> > int.from_bytes(dbg_keyhash[:hashbytes], 'big') >> hashshift
> > (Pdb) p item
> > b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
> >
> > but it's just because item is a sentinel which shouldn't hash to its
> > index, can check for that

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