module/oop/goops/util.scm

   1 ;;;;    Copyright (C) 1999, 2000, 2001, 2003, 2006, 2008 Free Software Foundation, Inc.
   2 ;;;;
   3 ;;;; This library is free software; you can redistribute it and/or
   4 ;;;; modify it under the terms of the GNU Lesser General Public
   5 ;;;; License as published by the Free Software Foundation; either
   6 ;;;; version 2.1 of the License, or (at your option) any later version.
   7 ;;;;
   8 ;;;; This library is distributed in the hope that it will be useful,
   9 ;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 ;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11 ;;;; Lesser General Public License for more details.
  12 ;;;;
  13 ;;;; You should have received a copy of the GNU Lesser General Public
  14 ;;;; License along with this library; if not, write to the Free Software
  15 ;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  16 ;;;;
  17 \f
  18
  19 (define-module (oop goops util)
  20   :export (mapappend find-duplicate top-level-env top-level-env?
  21            map* for-each* length* improper->proper)
  22   :use-module (srfi srfi-1)
  23   :re-export  (any every)
  24   :no-backtrace
  25   )
  26
  27
  28 ;;;
  29 ;;; {Utilities}
  30 ;;;
  31
  32 (define mapappend append-map)
  33
  34 (define (find-duplicate l)      ; find a duplicate in a list; #f otherwise
  35   (cond
  36     ((null? l)                  #f)
  37     ((memv (car l) (cdr l))     (car l))
  38     (else                       (find-duplicate (cdr l)))))
  39
  40 (define (top-level-env)
  41   (let ((mod (current-module)))
  42     (if mod
  43         (module-eval-closure mod)
  44         '())))
  45
  46 (define (top-level-env? env)
  47   (or (null? env)
  48       (procedure? (car env))))
  49
  50 (define (map* fn . l)           ; A map which accepts dotted lists (arg lists
  51   (cond                         ; must be "isomorph"
  52    ((null? (car l)) '())
  53    ((pair? (car l)) (cons (apply fn      (map car l))
  54                           (apply map* fn (map cdr l))))
  55    (else            (apply fn l))))
  56
  57 (define (for-each* fn . l)      ; A for-each which accepts dotted lists (arg lists
  58   (cond                         ; must be "isomorph"
  59    ((null? (car l)) '())
  60    ((pair? (car l)) (apply fn (map car l)) (apply for-each* fn (map cdr l)))
  61    (else            (apply fn l))))
  62
  63 (define (length* ls)
  64   (do ((n 0 (+ 1 n))
  65        (ls ls (cdr ls)))
  66       ((not (pair? ls)) n)))
  67
  68 (define (improper->proper ls)
  69   (if (pair? ls)
  70       (cons (car ls) (improper->proper (cdr ls)))
  71       (list ls)))