ac26fe7554
Also, updates some of the mzlib files to point at `racket/*' libraries rather than to `scheme/*' ones.
105 lines
3.4 KiB
Racket
105 lines
3.4 KiB
Racket
#lang scribble/doc
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@(require "utils.rkt")
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@title{Miscellaneous Support}
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@defproc[(regexp-replaces [objname (or/c string? bytes? symbol?)]
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[substs (listof (list regexp? string?))])
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string?]{
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A function that is convenient for many interfaces where the foreign
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library has some naming convention that you want to use in your
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interface as well. The @racket[objname] argument can be any value
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that will be used to name the foreign object; it is first converted
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into a string, and then modified according to the given
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@racket[substs] list in sequence, where each element in this list is a
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list of a regular expression and a substitution string. Usually,
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@racket[regexp-replace*] is used to perform the substitution, except
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for cases where the regular expression begins with a @litchar{^} or
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ends with a @litchar{$}, in which case @racket[regexp-replace] is
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used.
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For example, the following makes it convenient to define Racket
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bindings such as @racket[foo-bar] for foreign names like
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@racket[MyLib_foo_bar]:
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@racketblock[
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(define mylib (ffi-lib "mylib"))
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(define-syntax defmyobj
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(syntax-rules (:)
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[(_ name : type ...)
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(define name
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(get-ffi-obj
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(regexp-replaces 'name '((#rx"-" "_")
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(#rx"^" "MyLib_")))
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mylib (_fun type ...)))]))
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(defmyobj foo-bar : _int -> _int)
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]}
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@defproc[(list->cblock [lst list?] [type ctype?]) any]{
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Allocates a memory block of an appropriate size, and initializes it
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using values from @racket[lst] and the given @racket[type]. The
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@racket[lst] must hold values that can all be converted to C values
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according to the given @racket[type].}
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@defproc[(vector->cblock [vec vector?] [type type?]) any]{
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Like @racket[list->cblock], but for Racket vectors.}
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@defproc[(vector->cpointer [vec vector?]) cpointer?]{
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Returns a pointer to an array of @racket[_scheme] values, which is the
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internal representation of @racket[vec].}
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@defproc[(flvector->cpointer [flvec flvector?]) cpointer?]{
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Returns a pointer to an array of @racket[_double] values, which is the
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internal representation of @racket[flvec].}
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@defproc[(saved-errno) exact-integer?]{
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Returns the value most recently saved (in the current thread) after a
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foreign call with a non-@racket[#f] @racket[#:save-errno] option (see
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@racket[_fun] and @racket[_cprocedure]).}
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@defproc[(lookup-errno [sym (or/c 'EINTR 'EEXIST 'EAGAIN)])
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exact-integer?]{
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Returns a platform-specific value corresponding to a Posix @tt{errno}
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symbol. The set of supported symbols is likely to expand in the
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future.}
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@defproc[(cast [v any/c] [from-type ctype?] [to-type ctype?]) any/c]{
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Converts @racket[v] from a value matching @racket[from-type] to a
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value matching @racket[to-type], where @racket[(ctype-sizeof from-type)]
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matches @racket[(ctype-sizeof to-type)].
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The conversion is equivalent to
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@racketblock[
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(let ([p (malloc from-type)])
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(ptr-set! p from-type v)
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(ptr-ref p to-type))
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]}
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@defproc[(cblock->list [cblock any/c] [type ctype?] [length exact-nonnegative-integer?])
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list?]{
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Converts C @racket[cblock], which is a vector of @racket[type]s, to a
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Racket list. The arguments are the same as in the
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@racket[list->cblock]. The @racket[length] must be specified because
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there is no way to know where the block ends.}
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@defproc[(cblock->vector [cblock any/c] [type ctype?] [length exact-nonnegative-integer?])
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vector?]{
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Like @racket[cblock->vector], but for Racket vectors.}
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