Portable Foreign Function Interface for R7RS schemes

Foreign function interface that is supported on multiple R7RS Sceheme implementations.

Any help in form of constructive advice and bug reports are appreciated.

Issue trackers

Maling lists

Jenkins.

For documentation run mkdocs serve or see docs/.

Goals

• Support only R7RS implementations
• Same interface on all implementations
  • Some things that are procedures on one implementation are macros on other, but they must behave the same
• Stability and being boring after 1.0.0 is reached

Non goals

• To have every possible FFI feature
• Compiling of used library C code at any point
  • That is no stubs, no C code generated by the library and so on
  • The pffi library itself may require compilation on installation

Status

Currently the interface of the library is in okay shape. It propably will not change much but no guarantees are being made just yet.

Due to supporting many different Scheme implementations, different parts of this software are in different stage. As a whole it is still in alpha stage. That said the interface should not be changing anymore and support for some implementations are in beta.

Implementation status

Alpha

Anything not in beta or done, not recommended to use.

Beta

Usage can be started but might still be quite buggy.

• Guile
• Sagittarius
• Racket

Done

Usage recommended.

Implementation table

	Chibi	Chicken 5	Cyclone	Gambit	Gauche	Gerbil	Guile	Kawa	Larceny	Mosh	Racket	Sagittarius	Skint	STklos	tr7	Ypsilon
pffi-init	X	X	X	X	X	X	X	X	X	X	X	X	X	X
pffi-size-of	X	X	X	X			X	X		X	X	X		X
pffi-shared-object-auto-load	X	X	X				X	X		X	X	X		X
pffi-shared-object-load	X	X	X				X	X		X	X	X		X
pffi-pointer-null	X	X	X				X	X		X	X	X		X
pffi-pointer-null?	X	X	X				X	X		X	X	X		X
pffi-pointer-allocate	X	X	X				X	X		X	X	X		X
pffi-pointer?	X	X	X				X	X		X	X	X		X
pffi-pointer-free	X	X	X				X	X		X	X	X		X
pffi-pointer-set!	X	X	X				X	X		X	X	X
pffi-pointer-get	X	X	X				X	X		X	X	X
pffi-string->pointer	X	X	X				X	X		X	X	X
pffi-pointer->string	X	X	X				X	X		X	X	X
pffi-struct-make	X	X	X	X	X	X	X	X	X	X	X	X	X	X	X	X
pffi-struct-size	X	X	X	X	X	X	X	X	X	X	X	X	X	X	X	X
pffi-struct-pointer	X	X	X	X	X	X	X	X	X	X	X	X	X	X	X	X
pffi-struct-offset-get	X	X	X	X	X	X	X	X	X	X	X	X	X	X	X	X
pffi-struct-get	X	X	X	X	X	X	X	X	X	X	X	X	X	X	X	X
pffi-struct-set!	X	X	X	X	X	X	X	X	X	X	X	X	X	X	X	X
pffi-define	X	X	X				X	X		X	X	X
pffi-define-callback		X					X			X	X	X

Usage notes

• Chibi
  • Install libffi-dev
  • Build with:
    • chibi-ffi retropikzel/r7rs-pffi/r7rs-pffi-chibi.stub
    • ${CC} -o retropikzel/r7rs-pffi/r7rs-pffi-chibi.so -fPIC -shared retropikzel/r7rs-pffi/r7rs-pffi-chibi.c -lchibi-scheme -lffi
• Chicken 5
  • Needs r7rs egg
• Kawa
  • Needs at least Java version 22
  • Needs jvm flags:
    • --add-exports java.base/jdk.internal.foreign.abi=ALL-UNNAMED
    • --add-exports java.base/jdk.internal.foreign.layout=ALL-UNNAMED
    • --add-exports java.base/jdk.internal.foreign=ALL-UNNAMED
    • --enable-native-access=ALL-UNNAMED
• Larceny
  • Runs on 32 bit mode
• Mosh
  • FFI only works on x86_64
• Racket
  • Needs racket-r7rs

Design/exploration/waiting for implementation features

• LIPS
  • Will work on nodejs by using some C FFI library from npm
  • Javascript side needs design
• Biwascheme
  • Will work on nodejs by using some C FFI library from npm
  • Javascript side needs design
• MIT-Scheme
• s7
• Airship
• Other gambit targets
  • Gambit compiles to different targets other than C too, for example Javascript. It would be cool and interesting to see if this FFI could also support some of those
  • When LIPS and Biwascheme Javascript side is done then Gambit should be done too
• s48-r7rs
• prescheme

Will/can not be supported

• Loko
  • Desires no C interop, I can respect that