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compilability of scripts
I would like scripts to be compilable on Scheme systems that offer a
compiler of some sort. This would allow the development of the script
to be done with an interpreter and when speed is needed it can be
Say we have a script "S.scm" that is invoked with the command
S.scm arg1 arg2 arg3
Compiling this script can be done using one of these approaches:
1) Use the compiler to generate an executable, say "S.exe", that can
be invoked directly as:
S.exe arg1 arg2 arg3
This requires launching the compiled script differently than the
noncompiled script, which is unfortunate. There is also the
problem (for the compiler) of sending the command-line arguments to
the right function. Conceivably the compiler could parse the
invocation of "scheme-script" in the script, but for this to be
practical the syntax of the shell part of the script should be a well
defined subset of the shell syntax, for example always of the form:
exec scheme-script "$0" --call <identifier> "$@"
Alternatively, the shell part of the script could be free-form
except that the first occurrence of "--call <identifier>" defines
the function to call, and it is assumed that "scheme-script"
receives all of the script arguments. This would allow
Windows scripts to use the Windows syntax:
scheme-script %0 --call <identifier> %*
2) Use the compiler to generate a "FASL file" (a compiled
representation of "S.scm" that can be loaded quickly), say
"S.fasl". This can be a bytecode file, a binary file, heap image,
etc. Scheme implementations which can generate FASL files
typically allow loading the file with (load "S.fasl") or a command
line option. Note that it is possible to define "scheme-script" so
S.scm arg1 arg2 arg3
calls "scheme-script S.scm ...", it will load the file "S.fasl"
instead of "S.scm" if "S.fasl" exists. For this to work and be
portable, SRFI 22 would have to define the filename extension of
FASL files, or specify that an implementation dependent search is
performed for a file to load with the same base name (i.e. "S").
Alternatively, this search for the file to load could be done by
"scheme-script" only if the script file argument has no extension
(under UNIX you can only invoke a script with the same extension as
its filename, but under Windows, scripts must have the extension
".BAT" or ".CMD" and can be invoked with or without the extension).
So, a script "S.scm" will always load "S.scm", but a script "S" may
load "S.fasl", "S.foobar", "S.bat", "S", etc.
Could something like this be added to SRFI 22?