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Updating readme

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retropikzel 2025-01-25 13:55:50 +02:00
parent 607c8a3b84
commit 13f6c9241e
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218
README.md
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@ -168,27 +168,201 @@ initialisation run.
#### pffi-size-of #### pffi-size-of
**pffi-size-of** type **pffi-size-of** type -> number
Returns the size of the type.
pffi-align-of #### pffi-align-of
pffi-shared-object-auto-load
pffi-shared-object-load **pffi-align-of** type -> number
pffi-pointer-null
pffi-pointer-null? Returns the align of the type.
pffi-pointer-allocate
pffi-pointer? #### pffi-shared-object-auto-load
pffi-pointer-free
pffi-pointer-set! TODO
pffi-pointer-get
pffi-string->pointer #### pffi-shared-object-load
pffi-pointer->string
pffi-struct-make **pffi-shared-object-load** headers path
pffi-struct-size
pffi-struct-pointer It is recommended to use the pffi-shared-object-auto-load instead of this
pffi-struct-offset-get directly.
pffi-struct-offset-get
pffi-struct-get Headers is a list of strings needed to be included, for example
pffi-struct-set!
pffi-define (list "curl/curl.h")
pffi-define-callback
Path is the full path of the shared object without any "lib" prefix or ".so/.dll" suffix. For example:
"curl"
### pffi-pointer-null
**pffi-pointer-null** -> pointer
Returns a new NULL pointer.
#### pffi-pointer-null?
**pffi-pointer-null?** pointer -> boolean
Returns #t if given pointer is null pointer, #f otherwise.
### pffi-pointer-allocate
**pffi-pointer-allocate** size -> pointer
Returns newly allocated pointer of given size.
### pffi-pointer?
**pffi-pointer?** object -> boolean
Returns #t if given object is pointer, #f otherwise.
### pffi-pointer-free
**pffi-pointer-free** pointer
Frees given pointer.
### pffi-pointer-set!
**pffi-pointer-set!** pointer type offset value
Sets the value on a pointer on given offset. For example:
(define p (pffi-pointer-allocate 128))
(pffi-pointer-set! p 'int 64 100)
Would set the offset of 64, on pointer p to value 100.
### pffi-pointer-get
**pffi-pointer-get** pointer type offset -> object
Gets the value from a pointer on given offset. For example:
(define p (pffi-pointer-allocate 128))
(pffi-pointer-set! p 'int 64 100)
(pffi-pointer-get p 'int 64)
> 100
### pffi-string->pointer
**pffi-string->pointer** string -> pointer
Makes pointer out of a given string.
### pffi-pointer->string
**pffi-pointer->string** pointer -> string
Makes string out of a given pointer.
### pffi-struct-make
**pffi-struct-make** name members . pointer -> pffi-struct
Creates a new pffi-struct and allocates pointer for it. The members argument is a list of member
names and types. For example:
(define s (pffi-struct-make 'test '((int . r) (int . g) (int . b))))
### pffi-struct-size
**pffi-struct-size** pffi-struct -> number
Returns the size of a given pffi-struct. For example:
(define s (pffi-struct-make 'test '((int . r) (int . g) (int . b))))
(pffi-struct-size s)
> 12
### pffi-struct-pointer
**pffi-struct-pointer** pffi-struct -> pointer
Returns the pointer that holds the struct content. You need to use this when passing a struct as
a pointer to foreign functions.
(define s (pffi-struct-make 'test '((int . r) (int . g) (int . b))))
(pffi-struct-pointer s)
### pffi-struct-offset-get
**pffi-struct-offset-get** member-name -> number
Returns the offset of a struct member with given name.
### pffi-struct-get
**pffi-struct-get** pffi-struct member-name -> object
Returns the value of the givens struct member.
### pffi-struct-set!
**pffi-struct-set!** pffi-struct member-name value
Sets the value of the givens struct member. It is up to you to make sure that the type of value is
correct.
### pffi-define
**pffi-define** scheme-name shared-object c-name return-type argument-types
Defines a new foreign function to be used from Scheme code. For example:
(define libc-stdlib
(cond-expand
(windows (pffi-shared-object-auto-load (list "stdlib.h") (list) "ucrtbase" (list "")))
(else (pffi-shared-object-auto-load (list "stdlib.h") (list) "c" (list "" ".6")))))
(pffi-define c-puts libc-stdlib 'puts 'int (list 'pointer))
(c-puts "Message brought to you by FFI!")
### pffi-define-callback
**pffi-define-callback** scheme-name return-type argument-types procedure
Defines a new Sceme function to be used as callback to C code. For example:
; Load the shared library
(define libc-stdlib
(cond-expand
(windows (pffi-shared-object-auto-load (list "stdlib.h") (list) "ucrtbase" (list "")))
(else (pffi-shared-object-auto-load (list "stdlib.h") (list) "c" (list "" ".6")))))
; Define C function that takes a callback
(pffi-define qsort libc-stdlib 'qsort 'void (list 'pointer 'int 'int 'callback))
; Define our callback
(pffi-define-callback compare
'int
(list 'pointer 'pointer)
(lambda (pointer-a pointer-b)
(let ((a (pffi-pointer-get pointer-a 'int 0))
(b (pffi-pointer-get pointer-b 'int 0)))
(cond ((> a b) 1)
((= a b) 0)
((< a b) -1)))))
; Create new array of ints to be sorted
(define array (pffi-pointer-allocate (* (pffi-size-of 'int) 3)))
(pffi-pointer-set! array 'int (* (pffi-size-of 'int) 0) 3)
(pffi-pointer-set! array 'int (* (pffi-size-of 'int) 1) 2)
(pffi-pointer-set! array 'int (* (pffi-size-of 'int) 2) 1)
(display array)
(newline)
;> (3 2 1)
; Sort the array
(qsort array 3 (pffi-size-of 'int) compare)
(display array)
(newline)
;> (1 2 3)

1
retropikzel/r7rs-pffi.sld
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@ -27,7 +27,6 @@
pffi-struct-size pffi-struct-size
pffi-struct-pointer pffi-struct-pointer
pffi-struct-offset-get pffi-struct-offset-get
pffi-struct-offset-get
pffi-struct-get pffi-struct-get
pffi-struct-set! pffi-struct-set!
pffi-define pffi-define