Session-ocaml
Session-ocaml is an implementation of session types in OCaml.
(NEW: the project page is now open at: http://www.ct.info.gifu-u.ac.jp/~keigoi/session-ocaml/)
How to try it
Prepare OCaml 4.05 and install findlib, ocamlbuild, ppx_tools.
We recommend to use opam
Install the compiler and prerequisite libraries. (NOTE: the version number has changed: 4.03 ==> 4.05)
opam switch 4.05.0
eval `opam config env`
opam install ocamlfind ocamlbuild ppx_tools
Then clone the repository and type following at the top directory:
git clone https://github.com/keigoi/session-ocaml.git
cd session-ocaml
./configure --prefix=$(dirname `which ocaml`)/..
make
make install
Then you can play with session-ocaml:
cd examples
make # build examples
rlwrap ocaml -short-paths # play with OCaml toplevel (utop will also do).
# rlwrap is a readline wrapper (recommended)
Argument -short-paths is optional (it makes ocaml show the shortest path for each type).
Note that .ocamlinit file automatically pre-loads all required packages into OCaml toplevel and sets -rectypes option.
It also does open Session.
If things seem broken, try git clean -fdxthen make (WARNING: this command erases all files except the original distribution).
Also, you can uninstall manually by ocamlfind remove session-ocaml.
Example
Macro for branching / selection
For branching on arbitrary labels, we provide a macro match%branch.
open Session
match%branch s with
| `apple -> send 100
| `banana -> recv ()
| `orange -> send "Hello!"Its protocol type will be:
[`branch of resp *
[ `apple of [`msg of req * int * 'a]
| `banana of [`msg of resp * 'v * 'a]
| `orange of [`msg of req * string * 'a]]
Similarly, we have a macro for selection, like
[%select s `label]author: Keigo IMAI (@keigoi on Twitter / keigoi AT gifu-u.ac.jp)