https://github.com/effect-handlers/effects-rosetta-stone
A comparison of how computational effects and handlers are implemented in various programming languages.
https://github.com/effect-handlers/effects-rosetta-stone
Last synced: 8 months ago
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A comparison of how computational effects and handlers are implemented in various programming languages.
- Host: GitHub
- URL: https://github.com/effect-handlers/effects-rosetta-stone
- Owner: effect-handlers
- License: mit
- Created: 2018-04-23T15:41:03.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2019-03-29T02:38:37.000Z (almost 7 years ago)
- Last Synced: 2024-11-14T17:47:36.455Z (about 1 year ago)
- Language: Shell
- Size: 63.5 KB
- Stars: 132
- Watchers: 22
- Forks: 9
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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- awesome-list - effects-rosetta-stone - handlers | 102 | (Shell)
README
# Effects and handlers Rosetta stone
A collection of examples demonstrating programming with effects and handlers in
various programming languages.
[](https://travis-ci.org/effect-handlers/effects-rosetta-stone)
## How to contribute
### General guidelines
1. Each example instance should be self-contained.
2. Each example should demonstrate *one* aspect of effectful programming.
This does not mean it has to be simple.
3. In the naming of making comparisons possible, different implementations of a
single example should do *the same thing* as far as that is possible. For
instance, if there are *two* ways to implement an effect, e.g., state using
the usual monad and state using parametrized effects, then there should be
*two* examples which are identical, except for the implementation. If you
feel that the implementation is unnatural, please comment on this, but still
do it.
4. Do *not* print things out in examples that do not call for printing. Instead,
just compute whatever needs to be computed and store the results in top-level
values. Many languages will show the values anyhow, and that is as good as
printing.
5. All folder names are in lower case, with words separated by dashes, e.g.,
`cooperative-threads`, `multicore-ocaml`, `algol-68`.
### Repository structure
The repository contains examples in the `examples` folder, with a subfolder
`examples/example-x` for each *"Example X"*, and further containing:
* `README.md` contains a general description of the example
* `language-y` contains the example implemented in *"Language Y"*, which further
contains:
* an optional `README.md` contains further comments on the language
implementation of the example,
* a `Makefile` whose target `all` runs all the source code
* self-contained source code, following the established standards for the
programming language
### How to contribute a new programming language
To add a new programming language *My Language*, follow these steps:
1. Pick a lower-case name for the folders which contain examples written in My
Language, e.g., `my-language`.
2. Describe the language in the section *Languages* below. Use `my-language` as
the section name. Please provide links to the language home page and
installation instructions.
3. Implement at least one [example
instance](#how-to-contribute-an-example-instance) in your language.
### How to contribute a new example
To add a completely new example, follow these steps:
1. Pick a lower case folder name for the example, e.g., `example-x`.
2. Create a lower-case folder `examples/example-x` that will contain the example
and put in it `README.md` with a general description of the example. Please
follow the format of existing example descriptions.
3. Implement at least one [example
instance](#how-to-contribute-an-example-instance) so that it is clear what
needs to be implemented.
### How to contribute an example instance
To implement an example instance of `example-x` in `language-y`, create
`examples/example-x/language-y` and populate it, following the [repository
structure](#repository-structure) guidelines.
You may show several variants of the example. We recommend that you put them in
separate files, comment on them on the `README.md` file, and clearly mark one of
the examples as the *main* one. The main example is the one that people should
look at first.
### How to contribute an example non-instance
If something cannot be naturally implemented in your language, we want to know
about it! Create the folder `examples/example-x/language-y` and put in it
`README.md` which explains what the problem is.
You may add a *partial*, *simplified*, or *modified* implementation, in which
case you should explicitly describe the changes you made in `README.md`.
### May I improve other people's code?
Yes, we strongly encourage sharing and cooperation.
## Languages
An alphabetically ordered list of the languages used in the examples. The
section name must match the folder name used for that language.
### `eff`
The [Eff](http://www.eff-lang.org/) programming language can be installed
[through OPAM](https://github.com/matijapretnar/eff/#installing-with-opam),
compiled from [source code](https://github.com/matijapretnar/eff/), or [run in a
browser](http://www.eff-lang.org/try/).
To run Eff code contained in a file `example.eff`, run from the command line:
```bash
eff example.eff
```
You can also run `make` in the example directory and it will run all examples for you.
### `frank`
Install Frank from the [Frank GitHub repository](https://github.com/frank-lang/frank). To run
a Frank program contained in a file `example.fk`, run from the command line:
```bash
frank example.fk
```
### `koka`
[Koka](https://github.com/koka-lang/koka) (meaning "effective" in Japanese) can be installed from the [Koka Github repository](https://github.com/koka-lang/koka). It is best to clone the repository next to the
rosetta repository as the make files assume the Koka binary is located there, e.g.
from the same directory do:
```
> git clone https://github.com/effect-handlers/effects-rosetta-stone.git
> git clone https://github.com/koka-lang/koka.git
```
### `multicore-ocaml`
[Multicore OCaml](https://github.com/ocamllabs/ocaml-multicore) can be installed
through [OPAM](https://opam.ocaml.org):
```bash
$ opam remote add multicore https://github.com/ocamllabs/multicore-opam.git
$ opam switch 4.06.1+multicore
```
## About the repository
The participants of Dagstuhl seminar [Algebraic effect handlers go
mainstream](https://www.dagstuhl.de/en/program/calendar/semhp/?semnr=18172) have
initiated this repository of examples that show how to program with algebraic
effects and handlers in various languages.