Function

Summary

Copies the contents of one foreign or Lisp array into another.

Package

fli

Signature

replace-foreign-array to from &key start1 start2 end1 end2 => to

Arguments

to

A foreign array, foreign pointer or a Lisp array.

from

A foreign array, foreign pointer or a Lisp array.

start1

An integer.

start2

An integer.

end1

An integer.

end2

An integer.

Values

to

A foreign array, foreign pointer or a Lisp array.

Description

The function replace-foreign-array copies the contents of the array specified by from into another array specified by to . The arrays element types must have the same size and both be either signed or unsigned.

The argument to is destructively modified by copying successive elements into it from from . Elements of the subsequence of from bounded by start2 and end2 are copied into the subsequence of to bounded by start1 and end1 . If these subsequences are not of the same length, then the shorter length determines how many elements are copied; the extra elements near the end of the longer subsequence are not involved in the operation.

Each of to and from can be one of the following:

A lisp array.

The start and end are handled in the same way as Common Lisp sequence functions.

A foreign array.

The start and end are handled in the same way as Common Lisp sequence functions.

A pointer to a foreign array

The start and end are handled in the same way as Common Lisp sequence functions.

A pointer to any other foreign object.

In this case, the pointer is assumed to point to an array of such objects. Start and end are used as indices into that array, but without any bounds checking.

Example

This example demonstrates copying from a foreign pointer to a lisp array.

An initial array filled with 42:

(setq lisp-array 

      (make-array 10 

                  :element-type '(unsigned-byte 8)

                  :initial-element 42))

A foreign pointer to 10 consecutive unsigned chars:

(setq foreign-array

      (fli:allocate-foreign-object 

       :type '(:unsigned :char)

       :nelems 10

       :initial-contents '(1 2 3 4 5 6 7 8 9 10)))

Copy some of the unsigned char into the lisp array. Without :start2 and :end2 , only the first unsigned char would be copied:

(fli:replace-foreign-array 

 lisp-array foreign-array

 :start1 3

 :start2 5 :end2 8)

=>

#(42 42 42 6 7 8 42 42 42 42)

This example demonstrates copying from a foreign array to a lisp array.

A pointer to a foreign array of 10 unsigned chars:

(setq foreign-array

      (fli:allocate-foreign-object 

       :type 

       '(:c-array (:unsigned :char) 10)))

(dotimes (i 10) 

  (setf (fli:foreign-aref foreign-array i) (1+ i)))

Copy part of the foreign array into the lisp array:

(fli:replace-foreign-array 

 lisp-array foreign-array :start1 7)

=>

#(42 42 42 6 7 8 42 1 2 3)

See also

allocate-foreign-object
copy-pointer
make-pointer
replace-foreign-object