89 lines
2.8 KiB
Org Mode
89 lines
2.8 KiB
Org Mode
#+TITLE: Where next for guile-prescheme?
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* TODO guile repl integration
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Currently the "prescheme" language definition is just scheme with a different
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default environment (aka. the "prelude", the stuff that's imported by default).
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In the Guile REPL you can =,L prescheme= to switch language, but it's not very
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useful because you stay in the guile-user module, which is Guile's default
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environment, not Pre-Scheme's!
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You can create a Pre-Scheme module and switch into it with some effort:
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#+BEGIN_SRC scheme
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(use-modules (system base language))
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(set-module-name! (default-environment 'prescheme) '(prescheme-user))
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,module prescheme-user
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,language prescheme
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#+END_SRC
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We need to make the process of "give me a Pre-Scheme REPL" easier. Maybe just
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ship a REPL launcher script which starts up in Pre-Scheme instead of Guile?
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* TODO translate s48 macros to syntax-case
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Scheme 48 uses "explicit renaming" macros, these should be ported to
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syntax-case.
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#+BEGIN_SRC scheme
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;; scheme48-1.9.2/scheme/alt/define-macro-define-syntax.scm
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(define-macro (define-syntax macro-name transformer . stuff)
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`(define-macro (,macro-name . args)
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(,transformer (cons ',macro-name args)
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(lambda (x) x)
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eq?)))
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#+END_SRC
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** DONE prescheme/s48-defenum.scm
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- define-enumeration
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** TODO prescheme/ps-defenum.scm
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- define-external-enumeration
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** DONE prescheme/prescheme.scm
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- goto
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- external
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* TODO start porting ps-compiler
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Above is just the emulation layer. The real work is the ps-compiler itself,
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which is written in Scheme 48 (and also Common Lisp apparently). This will
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involve:
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- rewrite s48 interfaces as guile modules
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- rewrite code using records to use Guile's (or emulate s48?)
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- rewrite macros from explicit renaming to syntax-case
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- ... and many more unforeseen challenges...
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* TODO prepare some compatibility tests
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We need to find collect all the "real-world" Pre-Scheme we can get our hands on,
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and test that our Guile Pre-Scheme produces identical output to Scheme 48
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Pre-Scheme.
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Exhibit A is the "hello world" from the manual:
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#+BEGIN_SRC scheme
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;; https://thintz.com/resources/prescheme-documentation#Example-Pre_002dScheme-compiler-usage
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(define (main argc argv)
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(if (= argc 2)
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(let ((out (current-output-port)))
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(write-string "Hello, world, " out)
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(write-string (vector-ref argv 1) out)
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(write-char #\! out)
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(newline out)
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0)
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(let ((out (current-error-port)))
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(write-string "Usage: " out)
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(write-string (vector-ref argv 0) out)
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(write-string " <user>" out)
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(newline out)
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(write-string " Greets the world & <user>." out)
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(newline out)
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-1)))
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#+END_SRC
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A bunch of tests are included in scheme48-1.9.2/ps-compiler/prescheme/test.
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Nice!
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* TODO write more TODOs
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