<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <!--Rendered using the Haskell Html Library v0.2--> <HTML ><HEAD ><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=UTF-8" ><TITLE >Foreign.Marshal.Utils</TITLE ><LINK HREF="haddock.css" REL="stylesheet" TYPE="text/css" ><SCRIPT SRC="haddock-util.js" TYPE="text/javascript" ></SCRIPT ><SCRIPT TYPE="text/javascript" >window.onload = function () {setSynopsis("mini_Foreign-Marshal-Utils.html")};</SCRIPT ></HEAD ><BODY ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="topbar" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD ><IMG SRC="haskell_icon.gif" WIDTH="16" HEIGHT="16" ALT=" " ></TD ><TD CLASS="title" >base-4.2.0.2: Basic libraries</TD ><TD CLASS="topbut" ><A HREF="index.html" >Contents</A ></TD ><TD CLASS="topbut" ><A HREF="doc-index.html" >Index</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="modulebar" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD ><FONT SIZE="6" >Foreign.Marshal.Utils</FONT ></TD ><TD ALIGN="right" ><TABLE CLASS="narrow" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="infohead" >Portability</TD ><TD CLASS="infoval" >portable</TD ></TR ><TR ><TD CLASS="infohead" >Stability</TD ><TD CLASS="infoval" >provisional</TD ></TR ><TR ><TD CLASS="infohead" >Maintainer</TD ><TD CLASS="infoval" >ffi@haskell.org</TD ></TR ></TABLE ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="section4" ><B >Contents</B ></TD ></TR ><TR ><TD ><DL ><DT ><A HREF="#1" >General marshalling utilities </A ></DT ><DD ><DL ><DT ><A HREF="#2" >Combined allocation and marshalling </A ></DT ><DT ><A HREF="#3" >Marshalling of Boolean values (non-zero corresponds to <TT ><A HREF="Data-Bool.html#v%3ATrue" >True</A ></TT >) </A ></DT ><DT ><A HREF="#4" >Marshalling of Maybe values </A ></DT ><DT ><A HREF="#5" >Marshalling lists of storable objects </A ></DT ><DT ><A HREF="#6" >Haskellish interface to memcpy and memmove </A ></DT ></DL ></DD ></DL ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" >Description</TD ></TR ><TR ><TD CLASS="doc" >Utilities for primitive marshaling </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" >Synopsis</TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="body" ><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0" ><TR ><TD CLASS="decl" ><A HREF="#v%3Awith" >with</A > :: <A HREF="Foreign-Storable.html#t%3AStorable" >Storable</A > a => a -> (<A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a -> <A HREF="System-IO.html#t%3AIO" >IO</A > b) -> <A HREF="System-IO.html#t%3AIO" >IO</A > b</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3Anew" >new</A > :: <A HREF="Foreign-Storable.html#t%3AStorable" >Storable</A > a => a -> <A HREF="System-IO.html#t%3AIO" >IO</A > (<A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a)</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AfromBool" >fromBool</A > :: <A HREF="Prelude.html#t%3ANum" >Num</A > a => <A HREF="Data-Bool.html#t%3ABool" >Bool</A > -> a</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AtoBool" >toBool</A > :: <A HREF="Prelude.html#t%3ANum" >Num</A > a => a -> <A HREF="Data-Bool.html#t%3ABool" >Bool</A ></TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AmaybeNew" >maybeNew</A > :: (a -> <A HREF="System-IO.html#t%3AIO" >IO</A > (<A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a)) -> <A HREF="Data-Maybe.html#t%3AMaybe" >Maybe</A > a -> <A HREF="System-IO.html#t%3AIO" >IO</A > (<A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a)</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AmaybeWith" >maybeWith</A > :: (a -> (<A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > b -> <A HREF="System-IO.html#t%3AIO" >IO</A > c) -> <A HREF="System-IO.html#t%3AIO" >IO</A > c) -> <A HREF="Data-Maybe.html#t%3AMaybe" >Maybe</A > a -> (<A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > b -> <A HREF="System-IO.html#t%3AIO" >IO</A > c) -> <A HREF="System-IO.html#t%3AIO" >IO</A > c</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AmaybePeek" >maybePeek</A > :: (<A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a -> <A HREF="System-IO.html#t%3AIO" >IO</A > b) -> <A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a -> <A HREF="System-IO.html#t%3AIO" >IO</A > (<A HREF="Data-Maybe.html#t%3AMaybe" >Maybe</A > b)</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AwithMany" >withMany</A > :: (a -> (b -> res) -> res) -> [a] -> ([b] -> res) -> res</TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AcopyBytes" >copyBytes</A > :: <A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a -> <A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a -> <A HREF="Data-Int.html#t%3AInt" >Int</A > -> <A HREF="System-IO.html#t%3AIO" >IO</A > <A HREF="../ghc-prim-0.2.0.0/GHC-Unit.html#t%3A%28%29" >()</A ></TD ></TR ><TR ><TD CLASS="s8" ></TD ></TR ><TR ><TD CLASS="decl" ><A HREF="#v%3AmoveBytes" >moveBytes</A > :: <A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a -> <A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a -> <A HREF="Data-Int.html#t%3AInt" >Int</A > -> <A HREF="System-IO.html#t%3AIO" >IO</A > <A HREF="../ghc-prim-0.2.0.0/GHC-Unit.html#t%3A%28%29" >()</A ></TD ></TR ></TABLE ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section1" ><A NAME="1" ><A NAME="1" >General marshalling utilities </A ></A ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section2" ><A NAME="2" ><A NAME="2" >Combined allocation and marshalling </A ></A ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><A NAME="v:with" ><A NAME="v%3Awith" ></A ></A ><B >with</B > :: <A HREF="Foreign-Storable.html#t%3AStorable" >Storable</A > a => a -> (<A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a -> <A HREF="System-IO.html#t%3AIO" >IO</A > b) -> <A HREF="System-IO.html#t%3AIO" >IO</A > b</TD ></TR ><TR ><TD CLASS="doc" ><P ><TT ><TT ><A HREF="Foreign-Marshal-Utils.html#v%3Awith" >with</A ></TT > val f</TT > executes the computation <TT >f</TT >, passing as argument a pointer to a temporarily allocated block of memory into which <TT >val</TT > has been marshalled (the combination of <TT ><A HREF="Foreign-Marshal-Alloc.html#v%3Aalloca" >alloca</A ></TT > and <TT ><A HREF="Foreign-Storable.html#v%3Apoke" >poke</A ></TT >). </P ><P >The memory is freed when <TT >f</TT > terminates (either normally or via an exception), so the pointer passed to <TT >f</TT > must <EM >not</EM > be used after this. </P ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><A NAME="v:new" ><A NAME="v%3Anew" ></A ></A ><B >new</B > :: <A HREF="Foreign-Storable.html#t%3AStorable" >Storable</A > a => a -> <A HREF="System-IO.html#t%3AIO" >IO</A > (<A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a)</TD ></TR ><TR ><TD CLASS="doc" ><P >Allocate a block of memory and marshal a value into it (the combination of <TT ><A HREF="Foreign-Marshal-Alloc.html#v%3Amalloc" >malloc</A ></TT > and <TT ><A HREF="Foreign-Storable.html#v%3Apoke" >poke</A ></TT >). The size of the area allocated is determined by the Foreign.Storable.sizeOf method from the instance of <TT ><A HREF="Foreign-Storable.html#t%3AStorable" >Storable</A ></TT > for the appropriate type. </P ><P >The memory may be deallocated using Foreign.Marshal.Alloc.free or Foreign.Marshal.Alloc.finalizerFree when no longer required. </P ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section2" ><A NAME="3" ><A NAME="3" >Marshalling of Boolean values (non-zero corresponds to <TT ><A HREF="Data-Bool.html#v%3ATrue" >True</A ></TT >) </A ></A ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><A NAME="v:fromBool" ><A NAME="v%3AfromBool" ></A ></A ><B >fromBool</B > :: <A HREF="Prelude.html#t%3ANum" >Num</A > a => <A HREF="Data-Bool.html#t%3ABool" >Bool</A > -> a</TD ></TR ><TR ><TD CLASS="doc" >Convert a Haskell <TT ><A HREF="Data-Bool.html#t%3ABool" >Bool</A ></TT > to its numeric representation </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><A NAME="v:toBool" ><A NAME="v%3AtoBool" ></A ></A ><B >toBool</B > :: <A HREF="Prelude.html#t%3ANum" >Num</A > a => a -> <A HREF="Data-Bool.html#t%3ABool" >Bool</A ></TD ></TR ><TR ><TD CLASS="doc" >Convert a Boolean in numeric representation to a Haskell value </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section2" ><A NAME="4" ><A NAME="4" >Marshalling of Maybe values </A ></A ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><A NAME="v:maybeNew" ><A NAME="v%3AmaybeNew" ></A ></A ><B >maybeNew</B > :: (a -> <A HREF="System-IO.html#t%3AIO" >IO</A > (<A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a)) -> <A HREF="Data-Maybe.html#t%3AMaybe" >Maybe</A > a -> <A HREF="System-IO.html#t%3AIO" >IO</A > (<A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a)</TD ></TR ><TR ><TD CLASS="doc" ><P >Allocate storage and marshall a storable value wrapped into a <TT ><A HREF="Data-Maybe.html#t%3AMaybe" >Maybe</A ></TT > </P ><UL ><LI > the <TT ><A HREF="Foreign-Ptr.html#v%3AnullPtr" >nullPtr</A ></TT > is used to represent <TT ><A HREF="Data-Maybe.html#v%3ANothing" >Nothing</A ></TT > </LI ></UL ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><A NAME="v:maybeWith" ><A NAME="v%3AmaybeWith" ></A ></A ><B >maybeWith</B > :: (a -> (<A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > b -> <A HREF="System-IO.html#t%3AIO" >IO</A > c) -> <A HREF="System-IO.html#t%3AIO" >IO</A > c) -> <A HREF="Data-Maybe.html#t%3AMaybe" >Maybe</A > a -> (<A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > b -> <A HREF="System-IO.html#t%3AIO" >IO</A > c) -> <A HREF="System-IO.html#t%3AIO" >IO</A > c</TD ></TR ><TR ><TD CLASS="doc" >Converts a <TT >withXXX</TT > combinator into one marshalling a value wrapped into a <TT ><A HREF="Data-Maybe.html#t%3AMaybe" >Maybe</A ></TT >, using <TT ><A HREF="Foreign-Ptr.html#v%3AnullPtr" >nullPtr</A ></TT > to represent <TT ><A HREF="Data-Maybe.html#v%3ANothing" >Nothing</A ></TT >. </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><A NAME="v:maybePeek" ><A NAME="v%3AmaybePeek" ></A ></A ><B >maybePeek</B > :: (<A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a -> <A HREF="System-IO.html#t%3AIO" >IO</A > b) -> <A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a -> <A HREF="System-IO.html#t%3AIO" >IO</A > (<A HREF="Data-Maybe.html#t%3AMaybe" >Maybe</A > b)</TD ></TR ><TR ><TD CLASS="doc" >Convert a peek combinator into a one returning <TT ><A HREF="Data-Maybe.html#v%3ANothing" >Nothing</A ></TT > if applied to a <TT ><A HREF="Foreign-Ptr.html#v%3AnullPtr" >nullPtr</A ></TT > </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section2" ><A NAME="5" ><A NAME="5" >Marshalling lists of storable objects </A ></A ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><A NAME="v:withMany" ><A NAME="v%3AwithMany" ></A ></A ><B >withMany</B > :: (a -> (b -> res) -> res) -> [a] -> ([b] -> res) -> res</TD ></TR ><TR ><TD CLASS="doc" >Replicates a <TT >withXXX</TT > combinator over a list of objects, yielding a list of marshalled objects </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="section2" ><A NAME="6" ><A NAME="6" >Haskellish interface to memcpy and memmove </A ></A ></TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="doc" >(argument order: destination, source) </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><A NAME="v:copyBytes" ><A NAME="v%3AcopyBytes" ></A ></A ><B >copyBytes</B > :: <A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a -> <A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a -> <A HREF="Data-Int.html#t%3AInt" >Int</A > -> <A HREF="System-IO.html#t%3AIO" >IO</A > <A HREF="../ghc-prim-0.2.0.0/GHC-Unit.html#t%3A%28%29" >()</A ></TD ></TR ><TR ><TD CLASS="doc" >Copies the given number of bytes from the second area (source) into the first (destination); the copied areas may <EM >not</EM > overlap </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="decl" ><A NAME="v:moveBytes" ><A NAME="v%3AmoveBytes" ></A ></A ><B >moveBytes</B > :: <A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a -> <A HREF="Foreign-Ptr.html#t%3APtr" >Ptr</A > a -> <A HREF="Data-Int.html#t%3AInt" >Int</A > -> <A HREF="System-IO.html#t%3AIO" >IO</A > <A HREF="../ghc-prim-0.2.0.0/GHC-Unit.html#t%3A%28%29" >()</A ></TD ></TR ><TR ><TD CLASS="doc" >Copies the given number of bytes from the second area (source) into the first (destination); the copied areas <EM >may</EM > overlap </TD ></TR ><TR ><TD CLASS="s15" ></TD ></TR ><TR ><TD CLASS="botbar" >Produced by <A HREF="http://www.haskell.org/haddock/" >Haddock</A > version 2.6.1</TD ></TR ></TABLE ></BODY ></HTML >