;;;; "arraymap.scm", applicative routines for arrays in Scheme. ;;; Copyright (C) 1993, 2003 Aubrey Jaffer ; ;Permission to copy this software, to modify it, to redistribute it, ;to distribute modified versions, and to use it for any purpose is ;granted, subject to the following restrictions and understandings. ; ;1. Any copy made of this software must include this copyright notice ;in full. ; ;2. I have made no warranty or representation that the operation of ;this software will be error-free, and I am under no obligation to ;provide any services, by way of maintenance, update, or otherwise. ; ;3. In conjunction with products arising from the use of this ;material, there shall be no use of my name in any advertising, ;promotional, or sales literature without prior written consent in ;each case. (require 'array) ;;@code{(require 'array-for-each)} ;;@ftindex array-for-each ;;@args array0 proc array1 @dots{} ;;@var{array1}, @dots{} must have the same number of dimensions as ;;@var{array0} and have a range for each index which includes the range ;;for the corresponding index in @var{array0}. @var{proc} is applied to ;;each tuple of elements of @var{array1} @dots{} and the result is stored ;;as the corresponding element in @var{array0}. The value returned is ;;unspecified. The order of application is unspecified. (define (array-map! ra0 proc . ras) (define (ramap rdims inds) (if (null? (cdr rdims)) (do ((i (+ -1 (car rdims)) (+ -1 i)) (is (cons (+ -1 (car rdims)) inds) (cons (+ -1 i) inds))) ((negative? i)) (apply array-set! ra0 (apply proc (map (lambda (ra) (apply array-ref ra is)) ras)) is)) (let ((crdims (cdr rdims))) (do ((i (+ -1 (car rdims)) (+ -1 i))) ((negative? i)) (ramap crdims (cons i inds)))))) (ramap (reverse (array-dimensions ra0)) '())) ;;@args prototype proc array1 array2 @dots{} ;;@var{array2}, @dots{} must have the same number of dimensions as ;;@var{array1} and have a range for each index which includes the ;;range for the corresponding index in @var{array1}. @var{proc} is ;;applied to each tuple of elements of @var{array1}, @var{array2}, ;;@dots{} and the result is stored as the corresponding element in a ;;new array of type @var{prototype}. The new array is returned. The ;;order of application is unspecified. (define (array-map prototype proc ra1 . ras) (define nra (apply make-array prototype (array-dimensions ra1))) (apply array-map! nra proc ra1 ras) nra) ;;@args proc array0 @dots{} ;;@var{proc} is applied to each tuple of elements of @var{array0} @dots{} ;;in row-major order. The value returned is unspecified. (define (array-for-each proc . ras) (define (rafe rdims inds) (if (null? (cdr rdims)) (let ((sdni (reverse (cons #f inds)))) (define lastpair (last-pair sdni)) (do ((i 0 (+ 1 i))) ((> i (+ -1 (car rdims)))) (set-car! lastpair i) (apply proc (map (lambda (ra) (apply array-ref ra sdni)) ras)))) (let ((crdims (cdr rdims)) (ll (+ -1 (car rdims)))) (do ((i 0 (+ 1 i))) ((> i ll)) (rafe crdims (cons i inds)))))) (rafe (array-dimensions (car ras)) '())) ;;@args array ;;Returns an array of lists of indexes for @var{array} such that, if ;;@var{li} is a list of indexes for which @var{array} is defined, ;;(equal? @var{li} (apply array-ref (array-indexes @var{array}) ;;@var{li})). (define (array-indexes ra) (let ((ra0 (apply make-array '#() (array-dimensions ra)))) (array-index-map! ra0 list) ra0)) ;;@args array proc ;;applies @var{proc} to the indices of each element of @var{array} in ;;turn. The value returned and the order of application are ;;unspecified. ;; ;;One can implement @var{array-index-map!} as ;;@example ;;(define (array-index-map! ra fun) ;; (array-index-for-each ;; ra ;; (lambda is (apply array-set! ra (apply fun is) is)))) ;;@end example (define (array-index-for-each ra fun) (define (ramap rdims inds) (if (null? (cdr rdims)) (do ((i (+ -1 (car rdims)) (+ -1 i)) (is (cons (+ -1 (car rdims)) inds) (cons (+ -1 i) inds))) ((negative? i)) (apply fun is)) (let ((crdims (cdr rdims))) (do ((i (+ -1 (car rdims)) (+ -1 i))) ((negative? i)) (ramap crdims (cons i inds)))))) (if (zero? (array-rank ra)) (fun) (ramap (reverse (array-dimensions ra)) '()))) ;;@args array proc ;;applies @var{proc} to the indices of each element of @var{array} in ;;turn, storing the result in the corresponding element. The value ;;returned and the order of application are unspecified. ;; ;;One can implement @var{array-indexes} as ;;@example ;;(define (array-indexes array) ;; (let ((ra (apply make-array '#() (array-dimensions array)))) ;; (array-index-map! ra (lambda x x)) ;; ra)) ;;@end example ;;Another example: ;;@example ;;(define (apl:index-generator n) ;; (let ((v (make-vector n 1))) ;; (array-index-map! v (lambda (i) i)) ;; v)) ;;@end example (define (array-index-map! ra fun) (array-index-for-each ra (lambda is (apply array-set! ra (apply fun is) is)))) ;;@args destination source ;;Copies every element from vector or array @var{source} to the ;;corresponding element of @var{destination}. @var{destination} must ;;have the same rank as @var{source}, and be at least as large in each ;;dimension. The order of copying is unspecified. (define (array:copy! dest source) (array-map! dest identity source))