scm scm_f = {SPECIAL, "#f"};
scm scm_t = {SPECIAL, "#t"};
scm scm_dot = {SPECIAL, "."};
+scm scm_arrow = {SPECIAL, "=>"};
scm scm_undefined = {SPECIAL, "*undefined*"};
scm scm_unspecified = {SPECIAL, "*unspecified*"};
scm scm_closure = {SPECIAL, "*closure*"};
(apply f (apply cons* (cons h t)))))
(define-macro (cond . clauses)
- (list 'if (null? clauses) *unspecified*
- (if (null? (cdr clauses))
- (list 'if (car (car clauses))
- (list (cons 'lambda (cons '() (cons (car (car clauses)) (cdr (car clauses))))))
- *unspecified*)
- (if (eq? (car (cadr clauses)) 'else)
- (list 'if (car (car clauses))
- (list (cons 'lambda (cons '() (car clauses))))
- (list (cons 'lambda (cons '() (cons *unspecified* (cdr (cadr clauses)))))))
- (list 'if (car (car clauses))
- (list (cons 'lambda (cons '() (car clauses))))
- (cons 'cond (cdr clauses)))))))
+ (list 'if (pair? clauses)
+ (list (cons
+ 'lambda
+ (cons
+ '(test)
+ (list (list 'if 'test
+ (if (pair? (cdar clauses))
+ (if (eq? (cadar clauses) '=>)
+ (append2 (cddar clauses) '(test))
+ (list (cons 'lambda (cons '() (car clauses)))))
+ (list (cons 'lambda (cons '() (car clauses)))))
+ (if (pair? (cdr clauses))
+ (cons 'cond (cdr clauses)))))))
+ (car (car clauses)))))
(define else #t)
(helper (read)))
(define-macro (cond . clauses)
- (list (quote if) (null? clauses) *unspecified*
- (if (null? (cdr clauses))
- (list (quote if) (car (car clauses))
- (list (cons (quote lambda) (cons (list) (cons (car (car clauses)) (cdr (car clauses))))))
- *unspecified*)
- (if (eq? (car (cadr clauses)) (quote else))
- (list (quote if) (car (car clauses))
- (list (cons (quote lambda) (cons (list) (car clauses))))
- (list (cons (quote lambda) (cons (list) (cons *unspecified* (cdr (cadr clauses)))))))
- (list (quote if) (car (car clauses))
- (list (cons (quote lambda) (cons (list) (car clauses))))
- (cons (quote cond) (cdr clauses)))))))
-
+ (list 'if (pair? clauses)
+ (list 'if (car (car clauses))
+ (if (pair? (cdar clauses))
+ (if (eq? (cadar clauses) '=>)
+ (append2 (cddar clauses) (list (caar clauses)))
+ (list (cons 'lambda (cons '() (car clauses)))))
+ (list (cons 'lambda (cons '() (car clauses)))))
+ (if (pair? (cdr clauses))
+ (cons 'cond (cdr clauses))))))
+
(define (eat-whitespace)
(cond
((eq? (peek-byte) 9) (read-byte) (eat-whitespace))
(read-byte)
(cons (lookup (symbol->list (quote unsyntax-splicing)) a)
(cons (read-word (read-byte) w a) (list))))
- (else
+ (#t
(cons (lookup (symbol->list (quote unsyntax)) a)
(cons (read-word (read-byte) w a) (list))))))
((eq? (peek-byte) 39) (read-byte)
((eq? (peek-byte) 96) (read-byte)
(cons (lookup (cons (integer->char 35) (cons (integer->char 96) (list))) a)
(cons (read-word (read-byte) w a) (list))))
- (else (read-word (read-byte) (append2 w (cons (integer->char c) (list))) a))))
+ (#t (read-word (read-byte) (append2 w (cons (integer->char c) (list))) a))))
((eq? c 39) (if (null? w) (cons (lookup (cons (integer->char c) (list)) a)
(cons (read-word (read-byte) w a) (list)))
(begin (unread-byte c) (lookup w a))))
(cons
(lookup (symbol->list (quote unquote-splicing)) a)
(cons (read-word (read-byte) w a) (list)))))
- (else (cons (lookup-char c a) (cons (read-word (read-byte) w a)
+ (#t (cons (lookup-char c a) (cons (read-word (read-byte) w a)
(list))))))
((eq? c 96) (cons (lookup-char c a) (cons (read-word (read-byte) w a) (list))))
((eq? c 59) (read-line-comment c) (read-word 10 w a))
- (else (read-word (read-byte) (append2 w (cons (integer->char c) (list))) a))))
+ (#t (read-word (read-byte) (append2 w (cons (integer->char c) (list))) a))))
((lambda (p)
;;(display (quote scheme-program=)) (display p) (newline)
(pass-if "cond" (seq? (cond (#t)) #t))
(pass-if "cond 2" (seq? (cond (#f)) *unspecified*))
(pass-if "cond 3" (seq? (cond (#t 0)) 0))
- (pass-if "cond 3" (seq? (cond (#f 1) (#t 0)) 0)))
- )
+ (pass-if "cond 3" (seq? (cond (#f 1) (#t 0)) 0))
+ (pass-if-equal "cond => "
+ 0 (let ((lst '(0 1 2)))
+ (define (next)
+ (let ((r (car lst)))
+ (set! lst (cdr lst))
+ r))
+ (cond ((next) => identity))))))
(pass-if "and" (seq? (and 1) 1))
(pass-if "and 2" (seq? (and 1 (= 0 1) #f) #f))