Csexp: S-Expressions over the Network

Re:Csexp: S-Expressions over the Network by JonChesterfield on Sunday June 11, 2023 @05:20PM (#36285815)

I haven't worked on any of the classic lisp implementations but can speculate. I suppose the ratio of usefulness to difficulty of implementation doesn't work out.

Mutable state with serialise/deserialise either breaks the aliasing or needs some way to keep the referenced variables alive (nasty interaction with garbage collection) and to re-establish aliasing on deserialise.

Serialising a DAG to a tree tends to duplicate the previously shared nodes. There's then the question of whether deserialising the tree should re-establish the original sharing or some other sharing. Serialising a graph to a (finite) tree needs some notation to represent the cycles.

It looks to me like mutable state is the blocker but I'd be interested in other opinions.

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Re:Csexp: S-Expressions over the Network by aportnoy on Sunday June 11, 2023 @05:45PM (#36286054)

Yeah, something like "a" in the below code wouldn't have a "natural" serialization I don't think:

  (define a (list "a"))
  (define b (list "b"))
  (set-cdr! a b)
  (set-cdr! b a)

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