-;
-; 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
-(def (quote list) (lambda l l))
-
-(def (quote def!)
- (macro (name value)
- (list
- def
- (list quote name)
- value)
- )
- )
-
-(begin
- (def! append
- (lambda args
- (def! append-list
- (lambda (a b)
- (cond ((null? a) b)
- (else (cons (car a) (append-list (cdr a) b)))
- )
- )
- )
-
- (def! 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)
-
-(append '(a b c) '(d e f) '(g h i))
-
- ; boolean operators
-
-(begin
- (def! or
- (macro l
- (def! _or
- (lambda (l)
- (cond ((null? l) #f)
- ((null? (cdr l))
- (car l))
- (else
- (list
- cond
- (list
- (car l))
- (list
- 'else
- (_or (cdr l))
- )
- )
- )
- )
- )
- )
- (_or l)))
- 'or)
-
- ; execute to resolve macros
-
-(or #f #t)
-
-(begin
- (def! and
- (macro l
- (def! _and
- (lambda (l)
- (cond ((null? l) #t)
- ((null? (cdr l))
- (car l))
- (else
- (list
- cond
- (list
- (car l)
- (_and (cdr l))
- )
- )
- )
- )
- )
- )
- (_and l)
- )
- )
- 'and)
-
- ; execute to resolve macros
-
-(and #t #f)
-
-(begin
- (def! quasiquote
- (macro (x)
- (def! constant?
- ; A constant value is either a pair starting with quote,
- ; or anything which is neither a pair nor a symbol
-
- (lambda (exp)
- (cond ((pair? exp)
- (eq? (car exp) 'quote)
- )
- (else
- (not (symbol? exp))
- )
- )
- )
- )
- (def! combine-skeletons
- (lambda (left right exp)
- (cond
- ((and (constant? left) (constant? right))
- (cond ((and (eqv? (eval left) (car exp))
- (eqv? (eval right) (cdr exp)))
- (list 'quote exp)
- )
- (else
- (list 'quote (cons (eval left) (eval right)))
- )
- )
- )
- ((null? right)
- (list 'list left)
- )
- ((and (pair? right) (eq? (car right) 'list))
- (cons 'list (cons left (cdr right)))
- )
- (else
- (list 'cons left right)
- )
- )
- )
- )
-
- (def! expand-quasiquote
- (lambda (exp nesting)
- (cond
-
- ; non cons -- constants
- ; themselves, others are
- ; quoted
-
- ((not (pair? exp))
- (cond ((constant? exp)
- exp
- )
- (else
- (list 'quote exp)
- )
- )
- )
-
- ; check for an unquote exp and
- ; add the param unquoted
-
- ((and (eq? (car exp) 'unquote) (= (length exp) 2))
- (cond ((= nesting 0)
- (car (cdr exp))
- )
- (else
- (combine-skeletons ''unquote
- (expand-quasiquote (cdr exp) (- nesting 1))
- exp))
- )
- )
-
- ; nested quasi-quote --
- ; construct the right
- ; expression
-
- ((and (eq? (car exp) 'quasiquote) (= (length exp) 2))
- (combine-skeletons ''quasiquote
- (expand-quasiquote (cdr exp) (+ nesting 1))
- exp))
-
- ; check for an
- ; unquote-splicing member,
- ; compute the expansion of the
- ; value and append the rest of
- ; the quasiquote result to it
-
- ((and (pair? (car exp))
- (eq? (car (car exp)) 'unquote-splicing)
- (= (length (car exp)) 2))
- (cond ((= nesting 0)
- (list 'append (car (cdr (car exp)))
- (expand-quasiquote (cdr exp) nesting))
- )
- (else
- (combine-skeletons (expand-quasiquote (car exp) (- nesting 1))
- (expand-quasiquote (cdr exp) nesting)
- exp))
- )
- )
-
- ; for other lists, just glue
- ; the expansion of the first
- ; element to the expansion of
- ; the rest of the list
-
- (else (combine-skeletons (expand-quasiquote (car exp) nesting)
- (expand-quasiquote (cdr exp) nesting)
- exp)
- )
- )
- )
- )
- (def! result (expand-quasiquote x 0))
- result
- )
- )
- 'quasiquote)
-
- ;
- ; Define a variable without returning the value
- ; Useful when defining functions to avoid
- ; having lots of output generated.
- ;
- ; Also accepts the alternate
- ; form for defining lambdas of
- ; (define (name x y z) sexprs ...)
- ;
-
-(begin
- (def! define
- (macro (first . rest)
- ; check for alternate lambda definition form
-
- (cond ((pair? first)
- (set! rest
- (append
- (list
- 'lambda
- (cdr first))
- rest))
- (set! first (car first))
- )
- (else
- (set! rest (car rest))
- )
- )
- (def! result `(,begin
- (,def (,quote ,first) ,rest)
- (,quote ,first))
- )
- result
- )
- )
- 'define
- )
-
- ; basic list accessors
-
-(define (caar l) (car (car l)))
-
-(define (cadr l) (car (cdr l)))
-
-(define (cdar l) (cdr (car l)))
-
-(define (caddr l) (car (cdr (cdr l))))
-
- ; (if <condition> <if-true>)
- ; (if <condition> <if-true> <if-false)
-
-(define if
- (macro (test . args)
- (cond ((null? (cdr args))
- `(cond (,test ,(car args)))
- )
- (else
- `(cond (,test ,(car args))
- (else ,(cadr args)))
- )
- )
- )
- )
-
-(if (> 3 2) 'yes)
-(if (> 3 2) 'yes 'no)
-(if (> 2 3) 'no 'yes)
-(if (> 2 3) 'no)
-
- ; simple math operators
-
-(define zero? (macro (value) `(eq? ,value 0)))
-
-(zero? 1)
-(zero? 0)
-(zero? "hello")
-
-(define positive? (macro (value) `(> ,value 0)))
-
-(positive? 12)
-(positive? -12)
-
-(define negative? (macro (value) `(< ,value 0)))
-
-(negative? 12)
-(negative? -12)
-
-(define (abs x) (if (>= x 0) x (- x)))
-
-(abs 12)
-(abs -12)
-
-(define max (lambda (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 (lambda (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)
-
-(define (even? x) (zero? (% x 2)))
-
-(even? 2)
-(even? -2)
-(even? 3)
-(even? -1)
-
-(define (odd? x) (not (even? x)))
-
-(odd? 2)
-(odd? -2)
-(odd? 3)
-(odd? -1)
-
-
-(define (list-tail x k)
- (if (zero? k)
- x
- (list-tail (cdr x (- k 1)))
- )
- )
-
-(define (list-ref x k)
- (car (list-tail x k))
- )
-
- ; define a set of local
- ; variables all at once and
- ; then evaluate a list of
- ; sexprs
- ;
- ; (let (var-defines) sexprs)
- ;
- ; where var-defines are either
- ;
- ; (name value)
- ;
- ; or
- ;
- ; (name)
- ;
- ; e.g.
- ;
- ; (let ((x 1) (y)) (set! y (+ x 1)) y)
-
-(define let
- (macro (vars . exprs)
- (define (make-names vars)
- (cond ((not (null? vars))
- (cons (car (car vars))
- (make-names (cdr vars))))
- (else ())
- )
- )
-
- ; the parameters to the lambda is a list
- ; of nils of the right length
-
- (define (make-vals vars)
- (cond ((not (null? vars))
- (cons (cond ((null? (cdr (car vars))) ())
- (else
- (car (cdr (car vars))))
- )
- (make-vals (cdr vars))))
- (else ())
- )
- )
- ; prepend the set operations
- ; to the expressions
-
- ; build the lambda.
-
- `((lambda ,(make-names vars) ,@exprs) ,@(make-vals vars))
- )
- )
-
-
-(let ((x 1) (y)) (set! y 2) (+ x y))
-
- ; define a set of local
- ; variables one at a time and
- ; then evaluate a list of
- ; sexprs
- ;
- ; (let* (var-defines) sexprs)
- ;
- ; where var-defines are either
- ;
- ; (name value)
- ;
- ; or
- ;
- ; (name)
- ;
- ; e.g.
- ;
- ; (let* ((x 1) (y)) (set! y (+ x 1)) y)
-
-(define let*
- (macro (vars . exprs)
-
- ;
- ; make the list of names in the let
- ;
-
- (define (make-names vars)
- (cond ((not (null? vars))
- (cons (car (car vars))
- (make-names (cdr vars))))
- (else ())
- )
- )
-
- ; the set of expressions is
- ; the list of set expressions
- ; pre-pended to the
- ; expressions to evaluate
-
- (define (make-exprs vars exprs)
- (cond ((null? vars) exprs)
- (else
- (cons
- (list set
- (list quote
- (car (car vars))
- )
- (cond ((null? (cdr (car vars))) ())
- (else (cadr (car vars))))
- )
- (make-exprs (cdr vars) exprs)
- )
- )
- )
- )
-
- ; the parameters to the lambda is a list
- ; of nils of the right length
-
- (define (make-nils vars)
- (cond ((null? vars) ())
- (else (cons () (make-nils (cdr vars))))
- )
- )
- ; build the lambda.
-
- `((lambda ,(make-names vars) ,@(make-exprs vars exprs)) ,@(make-nils vars))
- )
- )
-
-(let* ((x 1) (y x)) (+ x y))
-
-(define when (macro (test . l) `(cond (,test ,@l))))
-
-(when #t (write 'when))
-
-(define unless (macro (test . l) `(cond ((not ,test) ,@l))))
-
-(unless #f (write 'unless))
-
-(define (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 x k)
- (if (zero? k)
- x
- (list-tail (cdr x) (- k 1))))
-
-(list-tail '(1 2 3) 2)
-
-(define (list-ref x k) (car (list-tail x k)))
-
-(list-ref '(1 2 3) 2)
-
- ; recursive equality
-
-(define (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))
-
-(define member (lambda (obj list . test?)
- (cond ((null? list)
- #f
- )
- (else
- (if (null? test?) (set! test? equal?) (set! test? (car test?)))
- (if (test? obj (car list))
- list
- (member obj (cdr list) test?))
- )
- )
- )
- )
-
-(member '(2) '((1) (2) (3)))
-
-(member '(4) '((1) (2) (3)))
-
-(define (memq obj list) (member obj list eq?))
-
-(memq 2 '(1 2 3))
-
-(memq 4 '(1 2 3))
-
-(memq '(2) '((1) (2) (3)))
-
-(define (memv obj list) (member obj list eqv?))
-
-(memv 2 '(1 2 3))
-
-(memv 4 '(1 2 3))
-
-(memv '(2) '((1) (2) (3)))
-
-(define (_assoc obj list test?)
- (if (null? list)
- #f
- (if (test? obj (caar list))
- (car list)
- (_assoc obj (cdr list) test?)
- )
- )
- )
-
-(define (assq obj list) (_assoc obj list eq?))
-(define (assv obj list) (_assoc obj list eqv?))
-(define (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")
-
-(define (char-upper-case? c) (<= #\A c #\Z))
-
-(char-upper-case? #\a)
-(char-upper-case? #\B)
-(char-upper-case? #\0)
-(char-upper-case? #\space)
-
-(define (char-lower-case? c) (<= #\a c #\a))
-
-(char-lower-case? #\a)
-(char-lower-case? #\B)
-(char-lower-case? #\0)
-(char-lower-case? #\space)
-
-(define (char-alphabetic? c) (or (char-upper-case? c) (char-lower-case? c)))
-
-(char-alphabetic? #\a)
-(char-alphabetic? #\B)
-(char-alphabetic? #\0)
-(char-alphabetic? #\space)
-
-(define (char-numeric? c) (<= #\0 c #\9))
-
-(char-numeric? #\a)
-(char-numeric? #\B)
-(char-numeric? #\0)
-(char-numeric? #\space)
-
-(define (char-whitespace? c) (or (<= #\tab c #\return) (= #\space c)))
-
-(char-whitespace? #\a)
-(char-whitespace? #\B)
-(char-whitespace? #\0)
-(char-whitespace? #\space)
-
-(define char->integer (macro (v) v))
-(define integer->char char->integer)
-
-(define (char-upcase c) (if (char-lower-case? c) (+ c (- #\A #\a)) c))
-
-(char-upcase #\a)
-(char-upcase #\B)
-(char-upcase #\0)
-(char-upcase #\space)
-
-(define (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 (lambda chars (list->string chars)))
-
-(display "apply\n")
-(apply cons '(a b))
-
-(define map
- (lambda (proc . lists)
- (define (args lists)
- (cond ((null? lists) ())
- (else
- (cons (caar lists) (args (cdr lists)))
- )
- )
- )
- (define (next lists)
- (cond ((null? lists) ())
- (else
- (cons (cdr (car lists)) (next (cdr lists)))
- )
- )
- )
- (define (domap lists)
- (cond ((null? (car lists)) ())
- (else
- (cons (apply proc (args lists)) (domap (next lists)))
- )
- )
- )
- (domap lists)
- )
- )
-
-(map cadr '((a b) (d e) (g h)))
-
-(define for-each (lambda (proc . lists)
- (apply map proc lists)
- #t))
-
-(for-each display '("hello" " " "world" "\n"))
-
-(define (_string-ml strings)
- (if (null? strings) ()
- (cons (string->list (car strings)) (_string-ml (cdr strings)))
- )
- )
-
-(define string-map (lambda (proc . strings)
- (list->string (apply map proc (_string-ml strings))))))
-
-(string-map (lambda (x) (+ 1 x)) "HAL")
-
-(define string-for-each (lambda (proc . strings)
- (apply for-each proc (_string-ml strings))))
-
-(string-for-each write-char "IBM\n")
-
-(define (newline) (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))
-
-
- ; `q -> (quote q)
- ; `(q) -> (append (quote (q)))
- ; `(a ,(+ 1 2)) -> (append (quote (a)) (list (+ 1 2)))
- ; `(a ,@(list 1 2 3) -> (append (quote (a)) (list 1 2 3))
-
-
-
-`(hello ,(+ 1 2) ,@(list 1 2 3) `foo)
-
-
-(define repeat
- (macro (count . rest)
- (define counter '__count__)
- (cond ((pair? count)
- (set! counter (car count))
- (set! count (cadr count))
- )
- )
- `(let ((,counter 0)
- (__max__ ,count)
- )
- (while (< ,counter __max__)
- ,@rest
- (set! ,counter (+ ,counter 1))
- )
- )
- )
- )
-
-(repeat 2 (write 'hello))
-(repeat (x 3) (write 'goodbye x))
-
-(define case
- (macro (test . l)
- ; construct the body of the
- ; case, dealing with the
- ; lambda version ( => lambda)
-
- (define (_unarrow l)
- (cond ((null? l) l)
- ((eq? (car l) '=>) `(( ,(cadr l) __key__)))
- (else l))
- )
-
- ; Build the case elements, which is
- ; simply a list of cond clauses
-
- (define (_case l)
-
- (cond ((null? l) ())
-
- ; else case
-
- ((eq? (caar l) 'else)
- `((else ,@(_unarrow (cdr (car l))))))
-
- ; regular case
-
- (else
- (cons
- `((eqv? ,(caar l) __key__)
- ,@(_unarrow (cdr (car l))))
- (_case (cdr l)))
- )
- )
- )
-
- ; now construct the overall
- ; expression, using a lambda
- ; to hold the computed value
- ; of the test expression
-
- `((lambda (__key__)
- (cond ,@(_case l))) ,test)
- )
- )
-
-(case 12 (1 "one") (2 "two") (3 => (lambda (x) (write "the value is" x))) (12 "twelve") (else "else"))