Revision 0fc3f039ee6e42f6a12c7d31ce54f02f6b79b5b2 authored by Jeff Bezanson on 04 September 2019, 16:37:47 UTC, committed by GitHub on 04 September 2019, 16:37:47 UTC
The static parameters of an outer scope should not be passed along to inner scopes; it instead needs to be handled by the lookup process iterating back to enclosing scopes.
1 parent fa235cc
utils.scm
;; for debugging, display x and return it
(define (prn x)
(with-output-to *stderr*
(display x) (newline))
x)
;; return the mapping for `elt` in `alst`, or `default` if not found
(define (lookup elt alst default)
(let ((a (assq elt alst)))
(if a (cdr a) default)))
;; items in `s1` and not in `s2`
(define (diff s1 s2)
(cond ((null? s1) '())
((memq (car s1) s2) (diff (cdr s1) s2))
(else (cons (car s1) (diff (cdr s1) s2)))))
(define (intersect s1 s2)
(filter (lambda (x) (memq x s2)) s1))
(define (has-dups lst)
(if (null? lst)
#f
(or (memq (car lst) (cdr lst))
(has-dups (cdr lst)))))
;; does `expr` contain any substructure that satisfies predicate `p`?
(define (contains p expr)
(or (p expr)
(and (pair? expr)
(any (lambda (x) (contains p x))
expr))))
;; does `expr` contain something `eq?` to `x`, excluding list heads and quoted exprs
(define (expr-contains-eq x expr)
(or (eq? expr x)
(and (pair? expr)
(not (quoted? expr))
(any (lambda (y) (expr-contains-eq x y))
(cdr expr)))))
;; same as above, with predicate
(define (expr-contains-p p expr (filt (lambda (x) #t)))
(and (filt expr)
(or (p expr)
(and (pair? expr)
(not (quoted? expr))
(any (lambda (y) (expr-contains-p p y filt))
(cdr expr))))))
;; find all subexprs satisfying `p`, applying `key` to each one
(define (expr-find-all p expr key (filt (lambda (x) #t)))
(if (filt expr)
(let ((found (if (p expr)
(list (key expr))
'())))
(if (or (atom? expr) (quoted? expr))
found
(apply nconc
found
(map (lambda (x) (expr-find-all p x key filt))
(cdr expr)))))
'()))
(define (butlast lst)
(if (or (null? lst) (null? (cdr lst)))
'()
(cons (car lst) (butlast (cdr lst)))))
(define (last lst)
(if (null? (cdr lst))
(car lst)
(last (cdr lst))))
(define (take-while f xs)
(cond ((null? xs) '())
((f (car xs)) (cons (car xs) (take-while f (cdr xs))))
(else '())))
(define (caddddr x) (car (cdr (cdr (cdr (cdr x))))))
(define (table.clone t)
(let ((nt (table)))
(table.foldl (lambda (k v z) (put! nt k v))
() t)
nt))
;; `any`, but call predicate on every element in order no matter what
(define (eager-any pred lst)
(let loop ((lst lst)
(any #f))
(if (null? lst)
any
(loop (cdr lst)
(or (pred (car lst)) any)))))
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