+;
+; Copyright © 2016 Keith Packard <keithp@keithp.com>
+;
+; This program is free software; you can redistribute it and/or modify
+; it under the terms of the GNU General Public License as published by
+; the Free Software Foundation, either version 2 of the License, or
+; (at your option) any later version.
+;
+; This program is distributed in the hope that it will be useful, but
+; WITHOUT ANY WARRANTY; without even the implied warranty of
+; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+; General Public License for more details.
+;
+; Lisp code placed in ROM
+
+ ; return a list containing all of the arguments
+
+(set (quote list) (lexpr (l) l))
+
+ ;
+ ; Define a variable without returning the value
+ ; Useful when defining functions to avoid
+ ; having lots of output generated
+ ;
+
+(set (quote define) (macro (name val rest)
+ (list
+ 'progn
+ (list
+ 'set
+ (list 'quote name)
+ val)
+ (list 'quote name)
+ )
+ )
+ )
+
+ ;
+ ; A slightly more convenient form
+ ; for defining lambdas.
+ ;
+ ; (defun <name> (<params>) s-exprs)
+ ;
+
+(define defun (macro (name args exprs)
+ (list
+ define
+ name
+ (cons 'lambda (cons args exprs))
+ )
+ )
+ )
+
; basic list accessors
-(setq cadr (lambda (l) (car (cdr l))))
-(setq caddr (lambda (l) (car (cdr (cdr l)))))
-(setq list (lexpr (l) l))
+(defun caar (l) (car (car l)))
- ; evaluate a list of sexprs
+(defun cadr (l) (car (cdr l)))
-(setq progn (lexpr (l) (last l)))
+(defun caddr (l) (car (cdr (cdr l))))
+
+(defun nth (list n)
+ (cond ((= n 0) (car list))
+ ((nth (cdr list) (1- n)))
+ )
+ )
; simple math operators
-(setq 1+ (lambda (x) (+ x 1)))
-(setq 1- (lambda (x) (- x 1)))
+(defun 1+ (x) (+ x 1))
+(defun 1- (x) (- x 1))
+
+(define zero? (macro (value rest)
+ (list
+ eq?
+ value
+ 0)
+ )
+ )
- ; define a variable without returning the value
+(zero? 1)
+(zero? 0)
+(zero? "hello")
-(set 'def (macro (def-param)
- (list
- 'progn
- (list
- 'set
- (list
- 'quote
- (car def-param))
- (cadr def-param)
- )
- (list
- 'quote
- (car def-param)
- )
- )
- )
+(define positive? (macro (value rest)
+ (list
+ >
+ value
+ 0)
+ )
+ )
+
+(positive? 12)
+(positive? -12)
+
+(define negative? (macro (value rest)
+ (list
+ <
+ value
+ 0)
+ )
+ )
+
+(negative? 12)
+(negative? -12)
+
+(defun abs (x) (cond ((>= x 0) x)
+ (else (- x)))
+ )
+
+(abs 12)
+(abs -12)
+
+(define max (lexpr (first rest)
+ (while (not (null? rest))
+ (cond ((< first (car rest))
+ (set! first (car rest)))
+ )
+ (set! rest (cdr rest))
+ )
+ first)
+ )
+
+(max 1 2 3)
+(max 3 2 1)
+
+(define min (lexpr (first rest)
+ (while (not (null? rest))
+ (cond ((> first (car rest))
+ (set! first (car rest)))
+ )
+ (set! rest (cdr rest))
+ )
+ first)
+ )
+
+(min 1 2 3)
+(min 3 2 1)
+
+(defun even? (x) (zero? (% x 2)))
+
+(even? 2)
+(even? -2)
+(even? 3)
+(even? -1)
+
+(defun odd? (x) (not (even? x)))
+
+(odd? 2)
+(odd? -2)
+(odd? 3)
+(odd? -1)
+
+(define exact? number?)
+(defun inexact? (x) #f)
+
+ ; (if <condition> <if-true>)
+ ; (if <condition> <if-true> <if-false)
+
+(define if (macro (test args)
+ (cond ((null? (cdr args))
+ (list
+ cond
+ (list test (car args)))
+ )
+ (else
+ (list
+ cond
+ (list test (car args))
+ (list 'else (cadr args))
+ )
+ )
+ )
+ )
)
+(if (> 3 2) 'yes)
+(if (> 3 2) 'yes 'no)
+(if (> 2 3) 'no 'yes)
+(if (> 2 3) 'no)
+
; define a set of local
; variables and then evaluate
; a list of sexprs
;
; e.g.
;
- ; (let ((x 1) (y)) (setq y (+ x 1)) y)
+ ; (let ((x 1) (y)) (set! y (+ x 1)) y)
-(def let (macro (let-param)
- ((lambda (vars exprs make-names make-exprs make-nils)
- (progn
+(define let (macro (vars exprs)
+ ((lambda (make-names make-exprs make-nils)
;
; make the list of names in the let
;
- (set 'make-names (lambda (vars)
- (cond (vars
- (cons (car (car vars))
- (make-names (cdr vars))))
- )
- )
- )
- ;
+ (set! make-names (lambda (vars)
+ (cond ((not (null? vars))
+ (cons (car (car vars))
+ (make-names (cdr vars))))
+ )
+ )
+ )
+
; the set of expressions is
; the list of set expressions
; pre-pended to the
; expressions to evaluate
- ;
- (set 'make-exprs (lambda (vars exprs)
- (progn
- (cond (vars (cons
- (list set
- (list quote
- (car (car vars))
- )
- (cadr (car vars))
- )
- (make-exprs (cdr vars) exprs)
- )
- )
- (exprs)
- )
- )
- )
- )
- (set 'exprs (make-exprs vars exprs))
- ;
- ; the parameters to the lambda is a list
- ; of nils of the right length
- ;
- (set 'make-nils (lambda (vars)
- (cond (vars (cons nil (make-nils (cdr vars))))
+ (set! make-exprs (lambda (vars exprs)
+ (cond ((not (null? vars))
+ (cons
+ (list set
+ (list quote
+ (car (car vars))
+ )
+ (cond ((null? (cdr (car vars))) ())
+ (else (cadr (car vars))))
+ )
+ (make-exprs (cdr vars) exprs)
+ )
+ )
+ (exprs)
)
)
- )
- ;
+ )
+
+ ; the parameters to the lambda is a list
+ ; of nils of the right length
+
+ (set! make-nils (lambda (vars)
+ (cond ((not (null? vars)) (cons () (make-nils (cdr vars))))
+ )
+ )
+ )
+ ; prepend the set operations
+ ; to the expressions
+
+ (set! exprs (make-exprs vars exprs))
+
; build the lambda.
- ;
- (set 'last-let-value
- (cons
- (list
- 'lambda
- (make-names vars)
- (cond ((cdr exprs) (cons 'progn exprs))
- ((car exprs))
- )
- )
- (make-nils vars)
- )
- )
- )
-
+
+ (cons (cons 'lambda (cons (make-names vars) exprs))
+ (make-nils vars)
+ )
)
- (car let-param)
- (cdr let-param)
()
()
()
)
)
)
+
+(let ((x 1)) x)
+
+ ; boolean operators
+
+(define or (lexpr (l)
+ (let ((ret #f))
+ (while (not (null? l))
+ (cond ((car l) (set! ret #t) (set! l ()))
+ ((set! l (cdr l)))))
+ ret
+ )
+ )
+ )
+
+ ; execute to resolve macros
+
+(or #f #t)
+
+(define and (lexpr (l)
+ (let ((ret #t))
+ (while (not (null? l))
+ (cond ((car l)
+ (set! l (cdr l)))
+ (#t
+ (set! ret #f)
+ (set! l ()))
+ )
+ )
+ ret
+ )
+ )
+ )
+
+ ; execute to resolve macros
+
+(and #t #f)
+
+
+(define append (lexpr (args)
+ (let ((append-list (lambda (a b)
+ (cond ((null? a) b)
+ (else (cons (car a) (append-list (cdr a) b)))
+ )
+ )
+ )
+ (append-lists (lambda (lists)
+ (cond ((null? lists) lists)
+ ((null? (cdr lists)) (car lists))
+ (else (append-list (car lists) (append-lists (cdr lists))))
+ )
+ )
+ )
+ )
+ (append-lists args)
+ )
+ )
+ )
+
+(append '(a b c) '(d e f) '(g h i))
+
+(defun reverse (list)
+ (let ((result ()))
+ (while (not (null? list))
+ (set! result (cons (car list) result))
+ (set! list (cdr list))
+ )
+ result)
+ )
+
+(reverse '(1 2 3))
+
+(define list-tail
+ (lambda (x k)
+ (if (zero? k)
+ x
+ (list-tail (cdr x) (- k 1)))))
+
+(list-tail '(1 2 3) 2)
+
+(defun list-ref (x k) (car (list-tail x k)))
+
+(list-ref '(1 2 3) 2)
+
+
+ ; recursive equality
+
+(defun equal? (a b)
+ (cond ((eq? a b) #t)
+ ((and (pair? a) (pair? b))
+ (and (equal? (car a) (car b))
+ (equal? (cdr a) (cdr b)))
+ )
+ (else #f)
+ )
+ )
+
+(equal? '(a b c) '(a b c))
+(equal? '(a b c) '(a b b))
+
+(defun _member (obj list test?)
+ (if (null? list)
+ #f
+ (if (test? obj (car list))
+ list
+ (memq obj (cdr list)))))
+
+(defun memq (obj list) (_member obj list eq?))
+
+(memq 2 '(1 2 3))
+
+(memq 4 '(1 2 3))
+
+(defun memv (obj list) (_member obj list eqv?))
+
+(memv 2 '(1 2 3))
+
+(memv 4 '(1 2 3))
+
+(defun member (obj list) (_member obj list equal?))
+
+(member '(2) '((1) (2) (3)))
+
+(member '(4) '((1) (2) (3)))
+
+(defun _assoc (obj list test?)
+ (if (null? list)
+ #f
+ (if (test? obj (caar list))
+ (car list)
+ (_assoc obj (cdr list) test?)
+ )
+ )
+ )
+
+(defun assq (obj list) (_assoc obj list eq?))
+(defun assv (obj list) (_assoc obj list eqv?))
+(defun assoc (obj list) (_assoc obj list equal?))
+
+(assq 'a '((a 1) (b 2) (c 3)))
+(assv 'b '((a 1) (b 2) (c 3)))
+(assoc '(c) '((a 1) (b 2) ((c) 3)))
+
+(define char? integer?)
+
+(char? #\q)
+(char? "h")
+
+(defun char-upper-case? (c) (<= #\A c #\Z))
+
+(char-upper-case? #\a)
+(char-upper-case? #\B)
+(char-upper-case? #\0)
+(char-upper-case? #\space)
+
+(defun char-lower-case? (c) (<= #\a c #\a))
+
+(char-lower-case? #\a)
+(char-lower-case? #\B)
+(char-lower-case? #\0)
+(char-lower-case? #\space)
+
+(defun char-alphabetic? (c) (or (char-upper-case? c) (char-lower-case? c)))
+
+(char-alphabetic? #\a)
+(char-alphabetic? #\B)
+(char-alphabetic? #\0)
+(char-alphabetic? #\space)
+
+(defun char-numeric? (c) (<= #\0 c #\9))
+
+(char-numeric? #\a)
+(char-numeric? #\B)
+(char-numeric? #\0)
+(char-numeric? #\space)
+
+(defun char-whitespace? (c) (or (<= #\tab c #\return) (= #\space c)))
+
+(char-whitespace? #\a)
+(char-whitespace? #\B)
+(char-whitespace? #\0)
+(char-whitespace? #\space)
+
+(defun char->integer (c) c)
+(defun integer->char (c) char-integer)
+
+(defun char-upcase (c) (if (char-lower-case? c) (+ c (- #\A #\a)) c))
+
+(char-upcase #\a)
+(char-upcase #\B)
+(char-upcase #\0)
+(char-upcase #\space)
+
+(defun char-downcase (c) (if (char-upper-case? c) (+ c (- #\a #\A)) c))
+
+(char-downcase #\a)
+(char-downcase #\B)
+(char-downcase #\0)
+(char-downcase #\space)
+
+(define string (lexpr (chars) (list->string chars)))
+
+(display "apply\n")
+(apply cons '(a b))
+
+(define map (lexpr (proc lists)
+ (let ((args (lambda (lists)
+ (if (null? lists) ()
+ (cons (caar lists) (args (cdr lists))))))
+ (next (lambda (lists)
+ (if (null? lists) ()
+ (cons (cdr (car lists)) (next (cdr lists))))))
+ (domap (lambda (lists)
+ (if (null? (car lists)) ()
+ (cons (apply proc (args lists)) (domap (next lists)))
+ )))
+ )
+ (domap lists))))
+
+(map cadr '((a b) (d e) (g h)))
+
+(define for-each (lexpr (proc lists)
+ (apply map proc lists)
+ #t))
+
+(for-each display '("hello" " " "world" "\n"))
+
+(define -string-ml (lambda (strings)
+ (if (null? strings) ()
+ (cons (string->list (car strings)) (-string-ml (cdr strings))))))
+
+(define string-map (lexpr (proc strings)
+ (list->string (apply map proc (-string-ml strings))))))
+
+(string-map 1+ "HAL")
+
+(define string-for-each (lexpr (proc strings)
+ (apply for-each proc (-string-ml strings))))
+
+(string-for-each write-char "IBM\n")
+
+(define newline (lambda () (write-char #\newline)))
+
+(newline)
+
+(call-with-current-continuation
+ (lambda (exit)
+ (for-each (lambda (x)
+ (write "test" x)
+ (if (negative? x)
+ (exit x)))
+ '(54 0 37 -3 245 19))
+ #t))
+
+;(define number->string (lexpr (arg opt)
+; (let ((base (if (null? opt) 10 (car opt)))
+ ;
+;
+