ToC | DocOverview | CGDoc | RelNotes | Index | PermutedIndex
| Allegro CL

| ANSI Common Lisp 15 Arrays 15.2 Dictionary of Arrays
15.2.18 array-row-major-index | Function
  Syntax: array-row-major-index array `&rest` subscripts index Arguments and Values: array - an array. subscripts - a list of valid array indices for the array. index - a valid array row-major index for the array. Description: Computes the position according to the row-major ordering of array for the element that is specified by subscripts, and returns the offset of the element in the computed position from the beginning of array. For a one-dimensional array, the result of array-row-major-index equals subscript. array-row-major-index ignores fill pointers. Examples:
       (setq a (make-array '(4 7) :element-type '(unsigned-byte 8)))
       (array-row-major-index a 1 2)  9
       (array-row-major-index
          (make-array '(2 3 4)
                      :element-type '(unsigned-byte 8)
                      :displaced-to a
                      :displaced-index-offset 4)
          0 2 1)  9
  Notes: A possible definition of array-row-major-index, with no error-checking, is
       (defun array-row-major-index (a &rest subscripts)
         (apply #'+ (maplist #'(lambda (x y)
                                  (* (car x) (apply #'* (cdr y))))
                             subscripts
                             (array-dimensions a))))
Allegro CL Implementation Details: None.

© Franz Inc. All Rights Reserved - File last updated 2022-07-25