# \[ANN\] ocaml-annot for binary annotations

**URL:** <https://discuss.ocaml.org/t/ann-ocaml-annot-for-binary-annotations/8683>\
**Category:** Ecosystem\
**Tags:** announce\
**Created:** [October 24, 2021, 5:03pm UTC](https://discuss.ocaml.org/t/ann-ocaml-annot-for-binary-annotations/8683 "2021-10-24T17:03:52Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![rixed](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ocaml.org/rixed/32/56_2.png) [@rixed](https://discuss.ocaml.org/u/rixed)\
**Post date:** [October 24, 2021, 5:03pm UTC](https://discuss.ocaml.org/t/ann-ocaml-annot-for-binary-annotations/8683/1 "2021-10-24T17:03:52Z")

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If, like me, you loved the convenience of [ocaml-annot](https://github.com/avsm/ocaml-annot) from a time where annotations were stored as mere text files, you might want to try [ocaml-bin-annot](https://github.com/rixed/ocaml-bin-annot), that does about the same thing with binary annotations.

In other words, `bin-annot -type lineno colno file.cmt` will print the type at the given location, which comes handy in an editor and much simpler to configure than merlin.

I haven’t tested on many cases or many compilers yet though, it’s still only a one day project so do not expect too much.

The main differences that I can see between `annot` and `bin-annot`:

- `bin-annot` is tied to a specific version of the OCaml compiler because of Marshalled cmt files, whereas `annot` can be installed once and forgotten;
- `bin-annot` is ten times larger than `annot`, again because it has to embed the compiler libs.