Here is the latest OCaml Weekly News, for the week of October 04 to 11, 2016.
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2016-10/msg00012.htmlContinuing this thread, Anil Madhavapeddy announced:
This has now been merged into OPAM repository and so should be available without the remote repository soon. I just wanted to thank Ivan for going through a huge amount of testing effort before submitting the PR, as can be seen here: https://github.com/ocaml/opam-repository/pull/7521 If anyone finds any issues after the merge, please do feel free to raise an issue on https://github.com/ocaml/opam-repository/issues
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2016-10/msg00019.htmlAndre Nathan continued this thread:
This is an interesting way to derive the GADT, at least for me, as I have never did any logic programming. The resulting API is a bit easier to use than the one from Jeremy's idea, at least for my use case. I'm using this idea to experiment with a type-safe SQL query builder, which so far looks like this: from Team.table |> belonging_to Team.owner Here |> having_one Project.leader Here |> select |> fields [field User.id; field User.name] (Next Here) |> fields [field Team.id; field Team.name] (Next (Next Here)) |> fields [all Project.table] Here This generates the following query: SELECT users.id, users.name, teams.id, teams.name, projects.* FROM teams LEFT JOIN users ON users.id = teams.owner_id LEFT JOIN projects ON projects.leader_id = users.id I'm not sure if this will ever be of use in practice, as the Next/Here stuff might be too complicated for users, but overall I'm quite happy with the result and what I've learned, though of course it's far from complete (e.g. no support for WHERE clauses).Daniel Bünzli then said:
You may be interested in looking at this http://okmij.org/ftp/meta-programming/#QUEL
Archive: https://sympa.inria.fr/sympa/arc/caml-list/2016-10/msg00021.htmlArthur Breitman announced:
Since blockchains tend to be a hot topic these days*, I am pleased to announce that OCaml is also present in this domain with the Tezos project. Tezos is a cryptographic ledger (in the same vein as Bitcoin or Ethereum) written from scratch entirely in OCaml, in partnership with OCamlPro. We are lucky to rely on some great OCaml libraries like Irmin and Lwt, and have contributed some libraries of our own like ocplib-json-typed (for reliable manipulation of JSON values) and ocplib-resto (for type safe HTTP/JSON RPCs). Tezos is a self-amending ledger. While other protocols achieve consensus about the state of their transactions, Tezos reaches a meta-consensus about its own protocol. This allows us to gradually build governance rules into the ledger by letting the participants choose under which condition the protocol may be amended. We start with a simple voting procedure to accept or reject a proposed patch to a set of OCaml modules representing the protocol. Over time, complex rules can evolve. For instance, we may introduce a form of constitutionalism by having the protocol require and enforce that any proposed modification be formally verified and guaranteed to preserve specific properties. If you find this intriguing and enjoy working in OCaml, please reach out: we're hiring! If you lean on the academic side and have experience with formal verification, reach out as well! We'd be interested in proving the correctness of some aspects of the protocol or sponsoring research in the field in general (within our modest means). Best, Arthur * perhaps hotter than it ought to be but, past the hype, there remains substance
Here are links from many OCaml blogs aggregated at OCaml Planet, http://ocaml.org/community/planet/. Five stages of accepting constructive mathematics http://math.andrej.com/2016/10/10/five-stages-of-accepting-constructive-mathematics/ Forge migration to a new host, delayed http://forge.ocamlcore.org/forum/forum.php?forum_id=943 Forge migration to a new host during the weekend http://forge.ocamlcore.org/forum/forum.php?forum_id=942 Conversion operations of the lambda-calculus http://blog.shaynefletcher.org/2016/10/conversion-operations-of-lambda-calculus.html
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