Xref: utzoo comp.lang.lisp:3504 comp.lang.lisp.franz:5
Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!orion.oac.uci.edu!ucivax!baxter
From: baxter@madeleine.ics.uci.edu (Ira Baxter)
Newsgroups: comp.lang.lisp,comp.lang.lisp.franz
Subject: Re: Trying to convert from Franz to Common lisp
Keywords: fexpr, lexpr needed
Message-ID: <26CC68EB.5205@ics.uci.edu>
Date: 17 Aug 90 22:00:12 GMT
References: <13416@sun.udel.edu> <3222@skye.ed.ac.uk>
Lines: 74
Nntp-Posting-Host: madeleine.ics.uci.edu

In case you want to convert DRACO to CommonLisp, this might be handy:

In <3222@skye.ed.ac.uk> jeff@aiai.ed.ac.uk (Jeff Dalton) writes:

>In article <13416@sun.udel.edu> vandyke@sun.udel.edu (Julie A Vandyke) writes:
>>I am needing a common lisp implementation of fexpr and lexpr.
>>Does anyone have or know of one before I work on the
>>problem myself? I'd love to save myself some effort.
>>
>>Thanx in advance for any help-
>>
>>Email please, as I do not usually read this newsgroup.

>I also e-mailed this (plus some other Franz hacks) but thoght
>this might be of general interest.  I wrote this code long
>ago so I can no longer remember for sure whether it all works.

>------------------------------

>;;;; def
>;;;
>;;; This is one way to let people define nlambdas (fexprs), lexprs, and
>;;; vanilla (non-defmacro) Franz macros.  'Apply' will work with lexprs
>;;; but not with fexprs or macros
>;;;

>(defmacro def (name (type formals &body body))
>  (case type
>    (lambda
>     `(defun ,name ,formals ,@body))
>    (nlambda
>     (if (/= (length formals) 1)
>	 (error "Def: fexpr ~S must have exactly one formal parameter." name))
>     (let ((real-name
>	    (intern (concatenate 'string "REAL-" (symbol-name name)))))
>       `(progn
>	 (defun ,real-name ,formals ,@body)
>	 (defmacro ,name (&rest .fexpr-args.)
>	   `(funcall #' ,',real-name ', .fexpr-args.)))))
>    (lexpr
>     (if (/= (length formals) 1)
>	 (error "Def: lexpr ~S must have exactly one formal parameter." name)
>	 `(defun ,name (&rest .lexpr-args.)
>	    (let* ((.lexpr-nargs. (length .lexpr-args.))
>		   (,(first formals) .lexpr-nargs.))
>	      ,@body))))
>    (macro
>     (if (/= (length formals) 1)
>	 (error "Def: macro ~S must have exactly one formal parameter." name)
>	 `(defmacro ,name (&rest ,(first formals))
>	    (setq ,(first formals)		;/\/ hack for Kyoto
>		  (cons ',name ,(first formals)))
>	    ,@body)))
>    (t (error "Def: ~S is not a valid function type for function ~S."
>	      type name))))

>;;;; lexpr extras
>;;;
>;;; These are macros so they can reference '.lexpr-args.' despite
>;;; lexical scoping (hee hee).
>;;;

>(defmacro arg (&optional (n nil n-p))
>  (if n-p
>      `(elt .lexpr-args. ,n)	;? might want to do our own length check?
>      `(progn .lexpr-nargs.)))	;not just a variable so can't be set

>------------------------------

>Jeff Dalton,                      JANET: J.Dalton@uk.ac.ed
>AI Applications Institute,        ARPA:  J.Dalton%uk.ac.ed@nsfnet-relay.ac.uk
>Edinburgh University.             UUCP:  ...!ukc!ed.ac.uk!J.Dalton
--
Ira Baxter