compile-r7rs is a tool to compile Scheme programs, it aims for compability with SRFI-138.

Despite it's name it also supports R6RS. Schemers, unite! <3

Jenkins

• Notes
• Supported implementations
• Roadmap
• Dependencies
• Building
• Installation
• Usage
  • Chicken
  • Mosh
  • mit-scheme
  • Compiling a single library
  • Environment variables
• Usage with docker
• Usual RnRS project
  • File structure
  • Installation of your project
• How it works
  • Gambit
  • Racket
• Development
  • Adding new implementations
  • Misc notes

Notes

• No support for -D flag yet.
• Not all implementations support adding to beginning or end o load path so -I and -A might work the same

Supported implementations

Some implementations support both compiling and interpreting, in that case only the compiler functionality is used and the implementation is marked as compiler.

• chezscheme
  • interpreter
  • R6RS
• chibi
  • interpreter
  • R7RS
• chicken
  • compiler
  • R7RS
• cyclone
  • compiler
  • R7RS
• gambit
  • compiler
  • R7RS
• foment
  • interpreter
  • R7RS
• gauche
  • interpreter
  • R7RS
• guile
  • interpreter
  • R6RS
  • R7RS
    • Has include bug https://debbugs.gnu.org/cgi/bugreport.cgi?bug=66046 but for some reason it seems to work for me atleast sometimes
• ikarus
  • interpreter
  • R6RS
• ironscheme
  • interpreter
  • R6RS
• kawa
  • interpreter
  • R7RS
  • Native access is enabled by default so pffi can work
• larceny
  • interpreter
  • R6RS
  • R7RS
• loko
  • compiler
  • R6RS
  • R7RS
• meevax
  • r7rs
• mit-scheme
  • interpreter
  • R7RS
• mosh
  • interpreter
  • R6RS
  • R7RS
• racket
  • interpreter
    • Has compiling capabilities but I havent got them to work yet
  • r6rs
  • r7rs
• sagittarius
  • interpreter
  • R6RS
  • R7RS
• skint
  • interpreter
  • R7RS
• stklos
  • interpreter
  • R7RS
• tr7
  • interpreter
  • R7RS
• ypsilon
  • interpreter
  • R6RS
  • R7RS

Roadmap

• Support for more implementations
  • husk
    • Dont know how to add directories to load path yet, might not be implemented
    • r7rs
  • picrin
    • Might not be possible, seems to not have (include...) that works like others
    • r7rs
  • scheme-rs
    • Waiting for implementation support
    • r6rs
    • r7rs
  • stak
    • Waiting for implementation support https://github.com/raviqqe/stak/issues/2355
    • r7rs
  • vicare
    • So old that I have problems compiling it in Docker, so testing is hard but I expect it to work once I get it to compile as it is R6RS implementation
    • r6rs
• Better and tested support for Windows
  • Right now there is support for running this but I can not quarantee it works on all if any cases
• Support for -D
  • Most implementations dont have this or equivalent flag, but it would be really nice feature to have so filing issues and implementing it myself is something I would like to do
• Ask implementations to support adding to the front and back of load path, or implement this onto implementations myself
  • This might not be as important, but it would be nice to go towards SRFI-138 conformaty
• Environment variable to force the target operating system
  • Since for example for interpreters the program produces .bat file with command to run the interpreter "cross compiling" is easy.

Dependencies

• (foreign c)
• (srfi 170)

To install:

snow-chibi --impls=SCHEME "(foreign c)"
snow-chibi --impls=SCHEME "(srfi 170)"

Building

The Makefile has build jobs for Schemes that compile-r7rs can be run with. The default is chibi. Run:

make build-SCHEME

Installation

Run:

make install

Usage

You need to install each Scheme implementation yourself.

The environment variable COMPILE_R7RS must be set to the name of the implementation as specified in the support list. This differs from the SRFI as the SRFI excepts a path.

To get the list of supported R6RS implementations run:

compile-r7rs --list-r6rs-schemes

To get the list of supported R7RS implementations run:

compile-r7rs --list-r7rs-schemes

To get the list of all supported implementations run:

compile-r7rs --list-schemes

Then run it with the .scm file for r7rs, or .sps file for r6rs.

COMPILE_R7RS=<implementation name> compile-r7rs -I . -o main main.scm

Which produces file called main, which you can run. Note that when given Scheme is interpreter the file contains commands that run the script, and even when the file is combiled binary it might need the compiled libraries.

No other file suffixes are supported at the moment.

Setting value of COMPILE_R7RS to implementation name that supports only r7rs and input file to .sps file and other way around is undefined behaviour.

Environment variables

• COMPILE_R7RS
  • Name of the implementation you want to compile with
  • This differs from the SRFI as it excepts a path
• COMPILE_R7RS_SCHEME_NAME
  • Additional string to insert right after the command and it's arguments can be used for example to pass C compiler flags on implementations that compile to C or anything or otherwise as backdoor
  • For example for Chicken to link with libcurl you would set COMPILE_R7RS_CHICKEN="-L -lcurl"
  • If implementation has - it is changed to _, for example mit-scheme -> MIT_SCHEME
  • This differs from the SRFI as it's not in there

Usage with Docker

The project has docker image.

It is statically built with Chicken scheme and installed under /opt/compile-r7rs, so it can be copied in your Dockerfile.

Here is a sample Dockerfile to get you started:

ARG SCHEME=chibi
FROM schemers/${SCHEME}
COPY --from=retropikzel1/compile-r7rs /opt/compile-r7rs /opt/compile-r7rs
ENV PATH=/opt/compile-r7rs/bin:${PATH}
ENV COMPILE_R7RS=${SCHEME}

To use this run:

docker build --build-arg SCHEME=${SCHEME} --tag=sometag .
docker run -v "${PWD}":/workdir -w /workdir -t sometag sh -c "compile-r7rs -I . -o main ./snow main.scm"

Usual RnRS projects

The reports do not say much, if anything, about the file structure of your project. However in practice certain patterns will repeat a lot. Here we use R7RS .sld and .scm files as example but for R6RS .sld = .sld and .scm = .sps.

File structure

The implementations most often expect library named (foo bar) to be in file foo/bar.sld. Some implementations add the current directory to the load path implicitly, some do not. If you store your libraries directly in your projects root it's propably best to always pass . as load path to compile-r7rs.

For example if your projects file structure is:

foo/bar.sld
main.scm

The command to compile and run this project is:

compile-r7rs -I . -o myproject main.scm
./myproject

If your project has more than one library then you propably want to store the libraries in one directory. For example:

snow/foo/bar.sld
main.scm

This is the case the compile-r7rs is tested against, main.scm imports (foo bar). The command to compile and run this project is:

compile-r7rs -I ./snow -o myproject main.scm
./myproject

Installation of your project

compile-r7rs (that is, this project) does not install your project files anywhere, that is left for you to do. I will update this section as I use this project more but here are some ideas. Basically each implementation might need it's own specific way and is outside of scope of this project.

Interpreters

The interpreters, that is for example Sagittarius, Gauche, Chibi and STklos, produce an executable that contains the command to run the main .scm file and add given paths to the implementations load paths. So if you run this:

compile-r7rs -I ./snow -o main main.scm

the resulting main file will only work in this directory, as the load path is relative. For system wide installation the paths would need to be more like this:

compile-r7rs -I /usr/local/lib/myproject/snow -o myproject main.scm

and then in makefile you would have:

install:
    mkdir -p /usr/local/lib/myproject
    cp -r snow /usr/local/lib/myproject/
    install myproject /usr/local/bin/

Compilers

Compilers, that is for example Chicken, Gambit, Cyclone either produce static executable or shared libraries. Cyclone produces static executable so if you run this:

compile-r7rs -I /usr/local/lib/myproject/snow -o myproject main.scm

and then in makefile you would have:

install:
    install myproject /usr/local/bin/

Chicken compiles shared object files and is different from that, like I said I hope to update this section when I get more experience with installing stuff compiled by using this project. :)

How it works

Gambit

To add library path into executables load path you need to compile Gambit script, not code. The script needs to be shebang and then the code:

#!/usr/bin/env gsi -:search=./snow
(import (scheme base)
        (scheme write))
(display "Hello world")
(newline)

So in order to do this compile-r7rs creates a main.tmp file that contains the shebang line, library directories you want and then your input files code.

Racket

r7rs

Racket only supports .rkt files, so the transformer creates .rkt file for each .sld file and the given .scm file. This file only needs to contain:

#!lang r7rs
(import (scheme base))
(include "file.scm/.sld")

Development

The program relies on two projects, r7rs-pffi and pffi-srfi-170. They both are stil work in progress so best way to help this project is to help on those projects. That said bug fixes for this projects are also welcome. Pull requests that add more SRFI-138 support are also welcome, but lets keep the scope on that.

The program itself is a quite straighforward transformer of SRFI-138 inputs to implementation specific inputs. It stands on the shoulders of giants and relies on the implementations to have all the needed features, then unifies the interface to use them.

Adding new implementations

The main program reads the flags and other inputs and passes them to a transformer functions. So to add support for new implementations you need to add the transformer functions and other data for it in libs/data.scm. You should be able to deduct how they work from other transformers. If you need to make utility functions add them into libs/util.scm and export them in libs/util.sld.

If the transformer has to go trough hoops, that is is little or much unusual then it is a good idea to explain how it works in this readmes how it works section.