suzanne.soy/racket
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mitch requests

Browse Source 
svn: r10795
This commit is contained in:
Eli Barzilay 2008-07-16 17:08:37 +00:00
parent 263feeb124
commit 44cc698c83
1 changed files with 12 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
collects/eopl/eopl.ss
View File

@ -104,11 +104,11 @@
;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(provide always? list-of) (provide always? list-of maybe)
(define always? (define always?
(lambda (x) #t)) (lambda (x) #t))
(define list-of (define list-of
(lambda (pred . l) (lambda (pred . l)
(let ((all-preds (cons pred l))) (let ((all-preds (cons pred l)))
@ -125,6 +125,12 @@
((car preds) (mcar obj)) ((car preds) (mcar obj))
(loop (mcdr obj) (cdr preds)))))))))) (loop (mcdr obj) (cdr preds))))))))))
(define maybe
(lambda (pred)
(lambda (obj)
(or (pred obj)
(eqv? obj #f)))))
;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(define empty null) (define empty null)
@ -134,7 +140,10 @@
empty ;; for constructor-based printing empty ;; for constructor-based printing
trace untrace ;; debugging trace untrace ;; debugging
require module ;; we allow full use of modules require module ;; we allow full use of modules
provide) ;; in case someone wants to use a module provide ;; in case someone wants to use a module
make-parameter ;; /
parameterize ;; < Mitch asked for these
print-struct) ;; \
(define-syntax r5rs-out (define-syntax r5rs-out
(syntax-rules () (syntax-rules ()