Installation
rtop is the name of the Reason REPL. Get it by installing Reason and BuckleScript globally:
$ npm install -g bs-platform reason-cli@latest-linux
(or reason-cli@latest-macos)
If you get the error Permission denied, you can solve it by adding --unsafe-perm:
$ npm install -g bs-platform reason-cli@latest-linux --unsafe-perm
(More about this issue on Github.)
Usage
You can now run rtop in your terminal:
$ rtop
If you have an up-to-date system, you might get the following error:
error while loading shared libraries: libncurses.so.5: cannot open shared object file: No such file or directory
Check if libncurses is installed. In my case, I had a newer version of the library.
Arch Linux:
$ pacman -Qs libncurses
> local/ncurses 6.1-6
On a Linux system, you can symlink version 5 with the installed version (i.e., version 6):
$ sudo ln -s /usr/lib/libncursesw.so.6.1 /usr/lib/libncurses.so.5
$ sudo ln -s /usr/lib/libtinfo.so.6 /usr/lib/libtinfo.so.5
Read more about this issue on StackOverflow.
Exit
rtop runs now smoothly. But how do you exit the REPL?
In most terminals, CTRL+C is what you’re looking for.
Strangely, that doesn’t work in rtop.
You have to use CTRL+D.
There is an open issue on Github that contains more information about rtops behavior.