Henry,
> On 14 Nov 2017, at 15:02, henry <he...@callistohouse.club> wrote:
>
> Hello, I am trying to extend STON to allow for substitutions as data is
> written out or read in. On the write side I got it working as #nextPut: is
> recursively called, so that is the perfect place to substitute before an
> object is written. I have tested and my changes work well, where I have an
> arbitrary object as a subObject and it gets substituted out for my Descriptor
> object.
OK good.
> I am having difficult on the read side identifying where a substitution
> lookup should occur after decoding the object on the input stream. I want to
> inflate the Descritpor object, with its data, and call for a possible
> substitution. As it is a Descriptor, it should get substituted with the right
> bits on the read side. I chose to try and do this in the method
> #setReference:to: and put the substitute into the objects list. This did not
> work. Where is a good place to look within STON to do a read-side
> post-substitution?
In
STONReader>>#parseObject
| targetClass reference object |
[
reference := self newReference.
targetClass := self parseClass.
object := targetClass fromSton: self.
self setReference: reference to: object ]
...
I would try just re-assigning object with your custom substitute. Like this
MySTONReader>>#parseObject
| targetClass reference object |
[
reference := self newReference.
targetClass := self parseClass.
object := targetClass fromSton: self.
object := object resolveSubstitution.
self setReference: reference to: object ]
...
The references are used if the same (#==) object is used twice, then you get
something like
STON fromString: '[Point[1,2],@2]'.
which is an 2 element Array where the exact same object is in both positions
(structure sharing). This works with circular references too (but be careful
because the inspector might loop).
HTH,
Sven
> Thank you.
>
> - HH
>
>
