perl6-inline-scheme-gambit's Introduction

Inline::Scheme::Gambit

This is a Raku module which allows execution of Gambit Scheme code from Raku code with inspiration from other Inline:: modules like Inline::Python, Inline::Lua, Inline::Scheme::Guile, etc.

Synopsis

use Inline::Scheme::Gambit;

my $gambit = Inline::Scheme::Gambit.new;

my $code = q:to/END/;
    (define (fib n)
     (if (< n 2) n (+ (fib (- n 1)) (fib (- n 2)))))
END

$gambit.run($code);
say $gambit.call('fib', 8);

say $gambit.call('map',
                 $gambit.run(q{(lambda (n) (fib n))}),
                 [0 .. 8]);

Status

Testing has only been done under Rakudo MoarVM on x86-64 Linux. It requires Gambit-C 4, and Gambit-C 4.8.3 and 4.2.8 have been tested by the author.

Values can be passed to and returned from Gambit-C. Simple types like boolean, integer, number, string, list, table, vector should work. Present mapping between Gambit-C and Raku types is as following table.

Gambit-C            from Perl                       to Perl
boolean             Bool                            Bool
integer(exact)      Int                             Int
rational(exact)     Rat                             Rat
rational(inexact)   Num                             Num
complex             Complex                         Complex
string              Stringy                         Str
list                Positional                      Array            
table               Associative                     Hash            
vector                                              Array
procedure                                           OpaquePointer
other objects       OpaquePointer                   OpaquePointer

Note that at present both scheme list and vector converts to Array in Raku, but through the call() method (see below) Raku Array only converts to list.

The API is incomplete and experimental. It may change in future if necessary.

To Do

Think about wrapping OpaquePointer for scheme-object, so that it can do better on scheme list/vector/procedure/etc.
Support scheme record type.
Improve error handling.

Install

zef install Inline::Scheme::Gambit

It by default tries to use 'gsc-script' or 'gsc' as the gsc command, and dynamically link to libgambc.so. It supports several environment variables to override the default behavior.

For example to override gsc in case 'gsc-script' or 'gsc' is not in PATH, or 'gsc-script' is an incorrect symlink.

GSC=/usr/bin/gsc zef install Inline::Scheme::Gambit

And if on your system gambit dll is not named libgambc.so, you can override it like below,

LIBS="-l:libgambit.so.4" zef install Inline::Scheme::Gambit

Or if you would like to static link to some libgambit.a

LIBS=-lutil MYEXTLIB=/usr/lib/gambit-c/libgambit.a zef install Inline::Scheme::Gambit

You can refer to Makefile.in and Build.pm to know more details.

Usage