PC-LISP
PC-LISP is an implementation of the Franz Lisp dialect by Peter Ashwood-Smith.[1][2][3]
Version 2.07 was released on 1 February 1986,[4] and version 3.00 was released on 1 February 1990.[1] A current version is available through GitHub.[2]
Currently, PC-LISP runs under 32 & 64 bit versions of Linux, Mac, Windows,[2] and NetBSD.[5] For NetBSD there also exists ports for AArch64, ARMv5/6/7, PowerPC, Motorola 68000, SPARC/SPARC64, Alpha and VAX.[5]
Note that the Franz LISP dialect was the immediate, portable successor to the ITS version of Maclisp[6] and is perhaps the closest thing to the LISP in the Steven Levy book Hackers as is practical to operate. PC-LISP is written primarily in the C programming language, with some parts now also written in Common Lisp.[2] Because PC-LISP implements Franz LISP, it is a dynamically scoped predecessor to modern Common Lisp.
Example
;; Demonstration of dynamic scoping
;; This is a "global" variable
(setq myglobal "this is my global variable")
;; Another global variable
(setq yourglobal "this is my global variable")
;; a function which prints the symbols
(defun dosomething (mine yours)
(princ " * Mine is - ")
(princ mine)
(princ "\n")
(princ " * Yours is - ")
(princ yours)
(princ "\n"))
;; override the symbols
(defun nolocals ()
(setq mine "I have set mine to a new value")
(setq yours "I have set yours to a new value")
(dosomething mine yours))
(defun main ()
;; define two symbols
(setq mine myglobal)
(setq yours yourglobal)
;; print them
(princ "calling dosomething\n")
(dosomething mine yours)
(princ "calling nolocals\n")
(nolocals)
(princ "calling dosomething again\n")
(dosomething mine yours))
; D(e,X) -
; Will compute the symbolic derivative of expression e with respect
; to variable X. We take the expression in standard lisp prefix form and will
; use the following rules of differentiation.
;
; D(x) = 1
; D(a) = 0
; D(ln u) = D(u)/u
; D(u+v) = D(u)+D(v)
; D(u-v) = D(u)-D(v)
; D(u*v) = D(u)*v + u*D(v)
; D(u/v) = D(u)*v + (u*D(v))/v^2
; D(v^u) = (v^u)*(u*D(v)/v + D(u)*ln(v))
;
(defun D(e X &aux u v)
(cond ((equal e X) 1)
((atom e) 0)
(t (setq u (cadr e) v (caddr e))
(caseq (car e)
(ln `(/ ,(D u X) ,u))
(+ `(+ ,(D u X) ,(D v X)))
(- `(- ,(D u X) ,(D v X)))
(* `(+ (* ,(D u X) ,v) (* ,(D v X) ,u)))
(/ `(- (/ ,(D u X) ,v)
(/ (* ,u ,(D v X)) (^ ,v 2))))
(^ `(* ,e (+ (/ (* ,v ,(D u X)) ,u)
(* ,(D v X) (ln ,u)))))
(t (princ "ERROR") (exit)]
References
- ↑ 1.0 1.1 Ashwood-Smith, Peter (1 February 1990). "PC-LISP V3.00 (C) February 1st 1990 Peter Ashwood-Smith". https://www.cs.cmu.edu/Groups/AI/lang/others/franzlsp/pclisp/readme.txt.
- ↑ 2.0 2.1 2.2 2.3 "blakemcbride/PC-LISP". 4 August 2020. https://github.com/blakemcbride/PC-LISP.
- ↑ Ashwood-Smith, Peter (May 1987). Van Deusen, Mary S.. ed. "PC-LISP". LISP Pointers 1 (1): 51-52. https://www.iment.com/maida/computer/lisp-ptrs/lp-i.1.51-2.htm. Retrieved 14 November 2024.
- ↑ Ashwood-Smith, Peter (20 February 1986). "A GUIDE TO THE PC-LISP INTERPRETER (V2.07)". https://www.tuhs.org/Usenet/comp.sources.unix/1986-February/003454.html.
- ↑ 5.0 5.1 "lang/pc-lisp - The NetBSD Packages Collection". https://cdn.netbsd.org/pub/pkgsrc/current/pkgsrc/lang/pc-lisp/index.html.
- ↑ Foderaro, John K.; Sklower, Keith L.; Layer, Kevin (June 1983). "FRANZ LISP". The FRANZ LISP Manual. pp. 5. https://github.com/blakemcbride/PC-LISP/blob/master/Franz_Lisp_July_1983.pdf.
External links
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