diff options
Diffstat (limited to 'tekuti/util.scm')
| -rw-r--r-- | tekuti/util.scm | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/tekuti/util.scm b/tekuti/util.scm index d594f28..edd8dba 100644 --- a/tekuti/util.scm +++ b/tekuti/util.scm @@ -28,7 +28,8 @@ #:use-module (match-bind) #:use-module (srfi srfi-1) #:export (expanduser match-lines dbg unwind-protect dbg dsu-sort - hash-push! list-has-length? list-head-match)) + hash-push! list-has-length? list-head-match mapn + list-intersperse)) (define (expanduser path) (let ((parts (string-split path #\/))) @@ -78,3 +79,15 @@ ((null? l2) #f) ((not (equal? (car l1) (car l2))) #f) (else (list-head-match (cdr l1) (cdr l2) (1- n))))) + +(define (mapn proc l nmax) + (let lp ((in l) (out '()) (n nmax)) + (if (or (null? in) (zero? n)) + (reverse out) + (lp (cdr in) (cons (proc (car in)) out) (1- n))))) + +(define (list-intersperse src-l elem) + (if (null? src-l) src-l + (let loop ((l (cdr src-l)) (dest (cons (car src-l) '()))) + (if (null? l) (reverse dest) + (loop (cdr l) (cons (car l) (cons elem dest))))))) |