Ppx_deriving implementation for pretty printing sets & maps

cdaringe · December 16, 2021, 5:37am

@vrotaru, no, it’s explicitly not supported:

github.com/ocaml-ppx/ppx_deriving

Raise an error when `type nonrec` is encountered

ocaml-ppx:master ← emillon:nonrec-raise-error

opened 10:58AM - 21 Dec 16 UTC

emillon

+19 -0

This feature has two different implementations in the AST: - in 4.02.3, it is… an annotation on a type, - in >= 4.03.0 it is straight in the constructor. Note that this can break existing programs; however relying on `ppx_deriving` to do the right thing in that case seems dangerous. Maybe an escape hatch could be added so that the recursive version is derived nonetheless. It is an intermediate solution to #116. Solving it is tricky because it would be necessary to expose this to the plugins, breaking the API. It is probably easier to do so once 4.02.3 support is dropped, since the per-type semantics are difficult to handle. Let me know what you think about these changes. Thanks!

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Ppx_deriving implementation for pretty printing sets & maps

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