Sophie: ghc-base-devel-4.2.0.2-8.6.fc14 x86

ghc-base-devel-4.2.0.2-8.6.fc14.x86_64.rpm

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>System.IO.Error</TITLE
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>base-4.2.0.2: Basic libraries</TD
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><A HREF="index.html"
>Contents</A
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><FONT SIZE="6"
>System.IO.Error</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"
>libraries@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"
>I/O errors
</A
></DT
><DD
><DL
><DT
><A HREF="#2"
>Classifying I/O errors
</A
></DT
><DT
><A HREF="#3"
>Attributes of I/O errors
</A
></DT
></DL
></DD
><DT
><A HREF="#4"
>Types of I/O error
</A
></DT
><DD
><DL
><DT
><A HREF="#5"
><TT
><A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TT
> predicates
</A
></DT
></DL
></DD
><DT
><A HREF="#6"
>Throwing and catching I/O errors
</A
></DT
></DL
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
>Description</TD
></TR
><TR
><TD CLASS="doc"
>Standard IO Errors.
</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"
><SPAN CLASS="keyword"
>type</SPAN
> <A HREF="#t%3AIOError"
>IOError</A
> = <A HREF="Control-Exception-Base.html#t%3AIOException"
>IOException</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AuserError"
>userError</A
> :: <A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AmkIOError"
>mkIOError</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="GHC-IO-Handle.html#t%3AHandle"
>Handle</A
> -&gt; <A HREF="Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="System-IO.html#t%3AFilePath"
>FilePath</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AannotateIOError"
>annotateIOError</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="GHC-IO-Handle.html#t%3AHandle"
>Handle</A
> -&gt; <A HREF="Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="System-IO.html#t%3AFilePath"
>FilePath</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisAlreadyExistsError"
>isAlreadyExistsError</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisDoesNotExistError"
>isDoesNotExistError</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisAlreadyInUseError"
>isAlreadyInUseError</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisFullError"
>isFullError</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisEOFError"
>isEOFError</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisIllegalOperation"
>isIllegalOperation</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisPermissionError"
>isPermissionError</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisUserError"
>isUserError</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AioeGetErrorType"
>ioeGetErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AioeGetLocation"
>ioeGetLocation</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AioeGetErrorString"
>ioeGetErrorString</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AioeGetHandle"
>ioeGetHandle</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="GHC-IO-Handle.html#t%3AHandle"
>Handle</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AioeGetFileName"
>ioeGetFileName</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="System-IO.html#t%3AFilePath"
>FilePath</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AioeSetErrorType"
>ioeSetErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AioeSetErrorString"
>ioeSetErrorString</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AioeSetLocation"
>ioeSetLocation</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AioeSetHandle"
>ioeSetHandle</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="GHC-IO-Handle.html#t%3AHandle"
>Handle</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AioeSetFileName"
>ioeSetFileName</A
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="System-IO.html#t%3AFilePath"
>FilePath</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><SPAN CLASS="keyword"
>data</SPAN
>  <A HREF="#t%3AIOErrorType"
>IOErrorType</A
> </TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AalreadyExistsErrorType"
>alreadyExistsErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AdoesNotExistErrorType"
>doesNotExistErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AalreadyInUseErrorType"
>alreadyInUseErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AfullErrorType"
>fullErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AeofErrorType"
>eofErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AillegalOperationErrorType"
>illegalOperationErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3ApermissionErrorType"
>permissionErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AuserErrorType"
>userErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisAlreadyExistsErrorType"
>isAlreadyExistsErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisDoesNotExistErrorType"
>isDoesNotExistErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisAlreadyInUseErrorType"
>isAlreadyInUseErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisFullErrorType"
>isFullErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisEOFErrorType"
>isEOFErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisIllegalOperationErrorType"
>isIllegalOperationErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisPermissionErrorType"
>isPermissionErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AisUserErrorType"
>isUserErrorType</A
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AioError"
>ioError</A
> ::  <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="System-IO.html#t%3AIO"
>IO</A
> a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Acatch"
>catch</A
> ::  <A HREF="System-IO.html#t%3AIO"
>IO</A
> a -&gt; (<A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="System-IO.html#t%3AIO"
>IO</A
> a) -&gt; <A HREF="System-IO.html#t%3AIO"
>IO</A
> a</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3Atry"
>try</A
> ::  <A HREF="System-IO.html#t%3AIO"
>IO</A
> a -&gt; <A HREF="System-IO.html#t%3AIO"
>IO</A
> (<A HREF="Data-Either.html#t%3AEither"
>Either</A
> <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> a)</TD
></TR
><TR
><TD CLASS="s8"
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="#v%3AmodifyIOError"
>modifyIOError</A
> ::  (<A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
>) -&gt; <A HREF="System-IO.html#t%3AIO"
>IO</A
> a -&gt; <A HREF="System-IO.html#t%3AIO"
>IO</A
> 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"
>I/O errors
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><SPAN CLASS="keyword"
>type</SPAN
> <A NAME="t:IOError"
><A NAME="t%3AIOError"
></A
></A
><B
>IOError</B
> = <A HREF="Control-Exception-Base.html#t%3AIOException"
>IOException</A
></TD
></TR
><TR
><TD CLASS="doc"
><P
>The Haskell 98 type for exceptions in the <TT
><A HREF="System-IO.html#t%3AIO"
>IO</A
></TT
> monad.
 Any I/O operation may raise an <TT
><A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TT
> instead of returning a result.
 For a more general type of exception, including also those that arise
 in pure code, see <A HREF="Control-Exception-Exception.html"
>Control.Exception.Exception</A
>.
</P
><P
>In Haskell 98, this is an opaque type.
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:userError"
><A NAME="v%3AuserError"
></A
></A
><B
>userError</B
> :: <A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="doc"
><P
>Construct an <TT
><A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TT
> value with a string describing the error.
 The <TT
><A HREF="Control-Monad.html#v%3Afail"
>fail</A
></TT
> method of the <TT
><A HREF="System-IO.html#t%3AIO"
>IO</A
></TT
> instance of the <TT
><A HREF="Control-Monad.html#t%3AMonad"
>Monad</A
></TT
> class raises a
 <TT
><A HREF="System-IO-Error.html#v%3AuserError"
>userError</A
></TT
>, thus:
</P
><PRE
> instance Monad IO where 
   ...
   fail s = ioError (userError s)
</PRE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:mkIOError"
><A NAME="v%3AmkIOError"
></A
></A
><B
>mkIOError</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="GHC-IO-Handle.html#t%3AHandle"
>Handle</A
> -&gt; <A HREF="Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="System-IO.html#t%3AFilePath"
>FilePath</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="doc"
>Construct an <TT
><A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TT
> of the given type where the second argument
 describes the error location and the third and fourth argument
 contain the file handle and file path of the file involved in the
 error if applicable.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:annotateIOError"
><A NAME="v%3AannotateIOError"
></A
></A
><B
>annotateIOError</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="GHC-IO-Handle.html#t%3AHandle"
>Handle</A
> -&gt; <A HREF="Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="System-IO.html#t%3AFilePath"
>FilePath</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="doc"
>Adds a location description and maybe a file path and file handle
 to an <TT
><A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TT
>.  If any of the file handle or file path is not given
 the corresponding value in the <TT
><A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TT
> remains unaltered.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section2"
><A NAME="2"
><A NAME="2"
>Classifying I/O errors
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isAlreadyExistsError"
><A NAME="v%3AisAlreadyExistsError"
></A
></A
><B
>isAlreadyExistsError</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>An error indicating that an <TT
><A HREF="System-IO.html#t%3AIO"
>IO</A
></TT
> operation failed because
 one of its arguments already exists.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isDoesNotExistError"
><A NAME="v%3AisDoesNotExistError"
></A
></A
><B
>isDoesNotExistError</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>An error indicating that an <TT
><A HREF="System-IO.html#t%3AIO"
>IO</A
></TT
> operation failed because
 one of its arguments does not exist.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isAlreadyInUseError"
><A NAME="v%3AisAlreadyInUseError"
></A
></A
><B
>isAlreadyInUseError</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>An error indicating that an <TT
><A HREF="System-IO.html#t%3AIO"
>IO</A
></TT
> operation failed because
 one of its arguments is a single-use resource, which is already
 being used (for example, opening the same file twice for writing
 might give this error).
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isFullError"
><A NAME="v%3AisFullError"
></A
></A
><B
>isFullError</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>An error indicating that an <TT
><A HREF="System-IO.html#t%3AIO"
>IO</A
></TT
> operation failed because
 the device is full.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isEOFError"
><A NAME="v%3AisEOFError"
></A
></A
><B
>isEOFError</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>An error indicating that an <TT
><A HREF="System-IO.html#t%3AIO"
>IO</A
></TT
> operation failed because
 the end of file has been reached.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isIllegalOperation"
><A NAME="v%3AisIllegalOperation"
></A
></A
><B
>isIllegalOperation</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>An error indicating that an <TT
><A HREF="System-IO.html#t%3AIO"
>IO</A
></TT
> operation failed because
 the operation was not possible.
 Any computation which returns an <TT
><A HREF="System-IO.html#t%3AIO"
>IO</A
></TT
> result may fail with
 <TT
><A HREF="System-IO-Error.html#v%3AisIllegalOperation"
>isIllegalOperation</A
></TT
>.  In some cases, an implementation will not be
 able to distinguish between the possible error causes.  In this case
 it should fail with <TT
><A HREF="System-IO-Error.html#v%3AisIllegalOperation"
>isIllegalOperation</A
></TT
>.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isPermissionError"
><A NAME="v%3AisPermissionError"
></A
></A
><B
>isPermissionError</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>An error indicating that an <TT
><A HREF="System-IO.html#t%3AIO"
>IO</A
></TT
> operation failed because
 the user does not have sufficient operating system privilege
 to perform that operation.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isUserError"
><A NAME="v%3AisUserError"
></A
></A
><B
>isUserError</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>A programmer-defined error value constructed using <TT
><A HREF="System-IO-Error.html#v%3AuserError"
>userError</A
></TT
>.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section2"
><A NAME="3"
><A NAME="3"
>Attributes of I/O errors
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:ioeGetErrorType"
><A NAME="v%3AioeGetErrorType"
></A
></A
><B
>ioeGetErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:ioeGetLocation"
><A NAME="v%3AioeGetLocation"
></A
></A
><B
>ioeGetLocation</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:ioeGetErrorString"
><A NAME="v%3AioeGetErrorString"
></A
></A
><B
>ioeGetErrorString</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Char.html#t%3AString"
>String</A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:ioeGetHandle"
><A NAME="v%3AioeGetHandle"
></A
></A
><B
>ioeGetHandle</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="GHC-IO-Handle.html#t%3AHandle"
>Handle</A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:ioeGetFileName"
><A NAME="v%3AioeGetFileName"
></A
></A
><B
>ioeGetFileName</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Maybe.html#t%3AMaybe"
>Maybe</A
> <A HREF="System-IO.html#t%3AFilePath"
>FilePath</A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:ioeSetErrorType"
><A NAME="v%3AioeSetErrorType"
></A
></A
><B
>ioeSetErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:ioeSetErrorString"
><A NAME="v%3AioeSetErrorString"
></A
></A
><B
>ioeSetErrorString</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:ioeSetLocation"
><A NAME="v%3AioeSetLocation"
></A
></A
><B
>ioeSetLocation</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="Data-Char.html#t%3AString"
>String</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:ioeSetHandle"
><A NAME="v%3AioeSetHandle"
></A
></A
><B
>ioeSetHandle</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="GHC-IO-Handle.html#t%3AHandle"
>Handle</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:ioeSetFileName"
><A NAME="v%3AioeSetFileName"
></A
></A
><B
>ioeSetFileName</B
> :: <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="System-IO.html#t%3AFilePath"
>FilePath</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
><A NAME="4"
><A NAME="4"
>Types of I/O error
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><SPAN CLASS="keyword"
>data</SPAN
>  <A NAME="t:IOErrorType"
><A NAME="t%3AIOErrorType"
></A
></A
><B
>IOErrorType</B
>  </TD
></TR
><TR
><TD CLASS="body"
><TABLE CLASS="vanilla" CELLSPACING="0" CELLPADDING="0"
><TR
><TD CLASS="ndoc"
>An abstract type that contains a value for each variant of <TT
><A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TT
>.
</TD
></TR
><TR
><TD CLASS="section4"
><IMG SRC="minus.gif" CLASS="coll" ONCLICK="toggle(this,'i:IOErrorType')" ALT="show/hide"
> Instances</TD
></TR
><TR
><TD CLASS="body"
><DIV ID="i:IOErrorType" STYLE="display:block;"
><TABLE CLASS="vanilla" CELLSPACING="1" CELLPADDING="0"
><TR
><TD CLASS="decl"
><A HREF="Data-Eq.html#t%3AEq"
>Eq</A
> <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="decl"
><A HREF="Text-Show.html#t%3AShow"
>Show</A
> <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
></TABLE
></DIV
></TD
></TR
></TABLE
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:alreadyExistsErrorType"
><A NAME="v%3AalreadyExistsErrorType"
></A
></A
><B
>alreadyExistsErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error where the operation failed because one of its arguments
 already exists.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:doesNotExistErrorType"
><A NAME="v%3AdoesNotExistErrorType"
></A
></A
><B
>doesNotExistErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error where the operation failed because one of its arguments
 does not exist.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:alreadyInUseErrorType"
><A NAME="v%3AalreadyInUseErrorType"
></A
></A
><B
>alreadyInUseErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error where the operation failed because one of its arguments
 is a single-use resource, which is already being used.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:fullErrorType"
><A NAME="v%3AfullErrorType"
></A
></A
><B
>fullErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error where the operation failed because the device is full.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:eofErrorType"
><A NAME="v%3AeofErrorType"
></A
></A
><B
>eofErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error where the operation failed because the end of file has
 been reached.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:illegalOperationErrorType"
><A NAME="v%3AillegalOperationErrorType"
></A
></A
><B
>illegalOperationErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error where the operation is not possible.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:permissionErrorType"
><A NAME="v%3ApermissionErrorType"
></A
></A
><B
>permissionErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error where the operation failed because the user does not
 have sufficient operating system privilege to perform that operation.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:userErrorType"
><A NAME="v%3AuserErrorType"
></A
></A
><B
>userErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error that is programmer-defined.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section2"
><A NAME="5"
><A NAME="5"
><TT
><A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
></TT
> predicates
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isAlreadyExistsErrorType"
><A NAME="v%3AisAlreadyExistsErrorType"
></A
></A
><B
>isAlreadyExistsErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error where the operation failed because one of its arguments
 already exists.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isDoesNotExistErrorType"
><A NAME="v%3AisDoesNotExistErrorType"
></A
></A
><B
>isDoesNotExistErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error where the operation failed because one of its arguments
 does not exist.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isAlreadyInUseErrorType"
><A NAME="v%3AisAlreadyInUseErrorType"
></A
></A
><B
>isAlreadyInUseErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error where the operation failed because one of its arguments
 is a single-use resource, which is already being used.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isFullErrorType"
><A NAME="v%3AisFullErrorType"
></A
></A
><B
>isFullErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error where the operation failed because the device is full.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isEOFErrorType"
><A NAME="v%3AisEOFErrorType"
></A
></A
><B
>isEOFErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error where the operation failed because the end of file has
 been reached.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isIllegalOperationErrorType"
><A NAME="v%3AisIllegalOperationErrorType"
></A
></A
><B
>isIllegalOperationErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error where the operation is not possible.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isPermissionErrorType"
><A NAME="v%3AisPermissionErrorType"
></A
></A
><B
>isPermissionErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error where the operation failed because the user does not
 have sufficient operating system privilege to perform that operation.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:isUserErrorType"
><A NAME="v%3AisUserErrorType"
></A
></A
><B
>isUserErrorType</B
> :: <A HREF="System-IO-Error.html#t%3AIOErrorType"
>IOErrorType</A
> -&gt; <A HREF="Data-Bool.html#t%3ABool"
>Bool</A
></TD
></TR
><TR
><TD CLASS="doc"
>I/O error that is programmer-defined.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="section1"
><A NAME="6"
><A NAME="6"
>Throwing and catching I/O errors
</A
></A
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:ioError"
><A NAME="v%3AioError"
></A
></A
><B
>ioError</B
> ::  <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="System-IO.html#t%3AIO"
>IO</A
> a</TD
></TR
><TR
><TD CLASS="doc"
>Raise an <TT
><A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TT
> in the <TT
><A HREF="System-IO.html#t%3AIO"
>IO</A
></TT
> monad.
</TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:catch"
><A NAME="v%3Acatch"
></A
></A
><B
>catch</B
> ::  <A HREF="System-IO.html#t%3AIO"
>IO</A
> a -&gt; (<A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="System-IO.html#t%3AIO"
>IO</A
> a) -&gt; <A HREF="System-IO.html#t%3AIO"
>IO</A
> a</TD
></TR
><TR
><TD CLASS="doc"
><P
>The <TT
><A HREF="System-IO-Error.html#v%3Acatch"
>catch</A
></TT
> function establishes a handler that receives any <TT
><A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TT
>
 raised in the action protected by <TT
><A HREF="System-IO-Error.html#v%3Acatch"
>catch</A
></TT
>.  An <TT
><A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TT
> is caught by
 the most recent handler established by <TT
><A HREF="System-IO-Error.html#v%3Acatch"
>catch</A
></TT
>.  These handlers are
 not selective: all <TT
><A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TT
>s are caught.  Exception propagation
 must be explicitly provided in a handler by re-raising any unwanted
 exceptions.  For example, in
</P
><PRE
> f = catch g (\e -&gt; if IO.isEOFError e then return [] else ioError e)
</PRE
><P
>the function <TT
>f</TT
> returns <TT
>[]</TT
> when an end-of-file exception
 (cf. <TT
><A HREF="System-IO-Error.html#v%3AisEOFError"
>isEOFError</A
></TT
>) occurs in <TT
>g</TT
>; otherwise, the
 exception is propagated to the next outer handler.
</P
><P
>When an exception propagates outside the main program, the Haskell
 system prints the associated <TT
><A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TT
> value and exits the program.
</P
><P
>Non-I/O exceptions are not caught by this variant; to catch all
 exceptions, use Control.Exception.catch from <A HREF="Control-Exception.html"
>Control.Exception</A
>.
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:try"
><A NAME="v%3Atry"
></A
></A
><B
>try</B
> ::  <A HREF="System-IO.html#t%3AIO"
>IO</A
> a -&gt; <A HREF="System-IO.html#t%3AIO"
>IO</A
> (<A HREF="Data-Either.html#t%3AEither"
>Either</A
> <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> a)</TD
></TR
><TR
><TD CLASS="doc"
><P
>The construct <TT
><A HREF="System-IO-Error.html#v%3Atry"
>try</A
></TT
> <TT
>comp</TT
> exposes IO errors which occur within a
 computation, and which are not fully handled.
</P
><P
>Non-I/O exceptions are not caught by this variant; to catch all
 exceptions, use Control.Exception.try from <A HREF="Control-Exception.html"
>Control.Exception</A
>.
</P
></TD
></TR
><TR
><TD CLASS="s15"
></TD
></TR
><TR
><TD CLASS="decl"
><A NAME="v:modifyIOError"
><A NAME="v%3AmodifyIOError"
></A
></A
><B
>modifyIOError</B
> ::  (<A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
> -&gt; <A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
>) -&gt; <A HREF="System-IO.html#t%3AIO"
>IO</A
> a -&gt; <A HREF="System-IO.html#t%3AIO"
>IO</A
> a</TD
></TR
><TR
><TD CLASS="doc"
>Catch any <TT
><A HREF="System-IO-Error.html#t%3AIOError"
>IOError</A
></TT
> that occurs in the computation and throw a
 modified version.
</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
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>