;;; -*-scheme-*-
;;; Mes --- Maxwell Equations of Software
-;;; Copyright © 2016 Jan Nieuwenhuizen <janneke@gnu.org>
+;;; Copyright © 2016,2017 Jan Nieuwenhuizen <janneke@gnu.org>
;;;
;;; This file is part of Mes.
;;;
(define (append-map f lst)
(apply append (map f lst)))
+(define (filter-map f lst)
+ (if (null? lst) (list)
+ (let ((r (f (car lst))))
+ (if r (cons r (filter-map f (cdr lst)))
+ (filter-map f (cdr lst))))))
+
;;; nyacc requirements
(define (fold proc init lst1 . rest)