Chapter 1: The Gambit-C system 1
1 The Gambit-C system
The Gambit programming system is a full implementation of the Scheme language which
conforms to the R4RS, R5RS and IEEE Scheme standards. It consists of two main programs:
gsi, the Gambit Scheme interpreter, and gsc, the Gambit Scheme compiler.
Gambit-C is a version of the Gambit programming system in which the compiler gen-
erates portable C code, making the whole Gambit-C system and the programs compiled
with it easily portable to many computer architectures for which a C compiler is available.
With appropriate declarations in the source code the executable programs generated by the
compiler run roughly as fast as equivalent C programs.
For the most up to date information on Gambit and add-on packages please check the
Gambit web page at http://gambit.iro.umontreal.ca. The web page has links to
the Gambit mailing list, the bug reporting system, and the source code repository.
1.1 Accessing the system files
Files related to Gambit, such as executables, libraries and header files, are stored in multiple
Gambit installation directories. Gambit may be installed on a system according to two
different installation models.
In the first model there is a single directory where all the Gambit installation directories
are stored. This central installation directory is typically /usr/local/Gambit-C under
UNIX, /Library/Gambit-C under Mac OS X and C:/Program Files/Gambit-C un-
der Microsoft Windows. This may have been overridden when the system was built with
the command ‘configure --prefix=/my/Gambit-C’. If the system was built with the
command ‘configure --enable-multiple-versions’ then the central installation
directory is prefix /version, where version is the system version string (e.g. v4.6.6 for
Gambit v4.6.6). Moreover, prefix /current will be a symbolic link which points to the
central installation directory. In this model, the Gambit installation directory named X is
simply the subdirectory X of the central installation directory.
In the second model some or all of the Gambit installation directories are stored
in installation specific directories. The location of these directories is assigned
when the system is built using the command ‘configure --bindir=/my/bin
--includedir=/my/include --libdir=/my/lib’.
The advantage of the first model is that it is easy to have multiple versions of Gambit
coexist and to remove all the files of a given version. However, the second model may be
necessary to conform to the package installation conventions of some operating systems.
Executable programs such as the interpreter gsi and compiler gsc can be found in the
bin installation directory. Adding this directory to the PATH environment variable allows
these programs to be started by simply entering their name. This is done automatically by
the Mac OS X and Microsoft Windows installers.
The runtime library is located in the lib installation directory. When the
system’s runtime library is built as a shared-library (with the command ‘configure
--enable-shared’) all programs built with Gambit-C, including the interpreter and
compiler, need to find this library when they are executed and consequently this directory
must be in the path searched by the system for shared-libraries. This path is normally
specified through an environment variable which is LD_LIBRARY_PATH on most versions
