NAME

chibi-scheme - a tiny Scheme interpreter

SYNOPSIS

chibi-scheme [-qQrRfTV] [-I path ] [-A path ] [-D feature ] [-m module ] [-x module ] [-l file ] [-e expr ] [-p expr ] [-t module.id ] [-d image-file ] [-i image-file ] [--] [ script argument ... ]

DESCRIPTION

chibi-scheme is a sample interactive Scheme interpreter for the chibi-scheme library. It serves as an example of how to embed chibi-scheme in applications, and can be useful on its own for writing scripts and interactive development.

When script is given, the script will be loaded with SRFI-22 semantics, calling the procedure main (if defined) with a single parameter as a list of the command-line arguments beginning with the script name. This works as expected with shell #! semantics.

Otherwise, if no script is given and no -e or -p options are given an interactive repl is entered, reading, evaluating, then printing expressions until EOF is reached. The repl provided is very minimal - if you want readline completion you may want to wrap it with the rlwrap(1) program. Signals aren't caught either - to enable handling keyboard interrupts you can use the (chibi process) module. For a more sophisticated REPL with readline support, signal handling, module management and smarter read/write you may want to use the (chibi repl) module. This can be launched automatically with: chibi-scheme -R .

For convenience the default language is the (scheme small) module, which includes every library in the R7RS small standard, and transitively some other dependencies. All of this together is actually quite large, so for a more minimal startup language you'll want to use the -x module option described below. To get a mostly R5RS-compatible language, use chibi-scheme -xscheme.r5rs or to get just the core language used for bootstrapping, use chibi-scheme -xchibi or its shortcut chibi-scheme -q .

OPTIONS

Space is optional between options and their arguments. Options without arguments may not be chained together.

To reduce the need for shell escapes, options with module arguments ( -m , -x and -R ) are written in a dot notation, so that the module (foo bar) is written as foo.bar .

-V: Prints the version information and exits.
-q: "Quick" load, shortcut for chibi-scheme -xchibi This is a slightly different language from (scheme base), which may load faster, and is guaranteed not to load any additional shared libraries.
-Q: Extra "quick" load, shortcut for chibi-scheme -xchibi.primitive The resulting environment will only contain the core syntactic forms and primitives coded in C. This is very fast and guaranteed not to load any external files, but is also very limited.
-r[main]: Run the "main" procedure when the script finishes loading as in SRFI-22.
-R[module]: Loads the given module and runs the "main" procedure it defines (which need not be exported) with a single argument of the list of command-line arguments as in SRFI-22. The name "main" can be overridden with the -r option. [module] may be omitted, in which case it defaults to chibi.repl. Thus chibi-scheme -R is the recommended means to obtain the advanced REPL.
-s: Strict mode, escalating warnings to fatal errors.
-f: Change the reader to case-fold symbols as in R5RS.
-T: Disables tail-call optimization. This can be useful for debugging in some cases, but also makes it very likely to overflow the stack.
-hsize[/max_size]: Specifies the initial size of the heap, in bytes, optionally followed by the maximum size the heap can grow to. size can be any integer value, optionally suffixed by "K", for kilobytes, "M" for megabytes, or "G" for gigabytes. -h must be specified before any options which load or evaluate Scheme code.
-Ipath: Inserts path on front of the load path list.
-Apath: Appends path to the load path list.
-Dfeature: Adds feature to the feature list, useful for cond-expanding different library code.
-mmodule
-xmodule: Imports module as though "(import module )" were evaluated. If the -x version is used, then module replaces the current environment instead of being added to it.
-lfile: Loads the Scheme source from the file file searched for in the default load path.
-eexpr: Evaluates the Scheme expression expr.
-pexpr: Evaluates the Scheme expression expr then prints the result to stdout.
-tmodule.id: Enables tracing for the given identifier id in the module module.
-dimage-file: Dumps the current Scheme heap to image-file and exits. This feature is still experimental.
-iimage-file: Loads the Scheme heap from image-file instead of compiling the init file on the fly. This feature is still experimental.
-b: Makes stdio nonblocking (blocking by default). Only available when lightweight threads are enabled.

ENVIRONMENT

CHIBI_MODULE_PATH

A colon separated list of directories to search for module files, inserted before the system default load paths. chibi-scheme searches for modules in directories in the following order:

directories included with the -I path option

directories included from CHIBI_MODULE_PATH

system directories

directories included with -A path option

If CHIBI_MODULE_PATH is unset, the directories "./lib", and "." are searched in order. Set to empty to only consider -I, system directories and -A.

CHIBI_IGNORE_SYSTEM_PATH

If set to anything but "0", system directories (as listed above) are not included in the search paths.

AUTHORS