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</script></head><body><div id="package-header"><ul class="links" id="page-menu"><li><a href="src/GHC-IO-Encoding-Types.html">Source</a></li><li><a href="index.html">Contents</a></li><li><a href="doc-index.html">Index</a></li></ul><p class="caption">base-4.3.1.0: Basic libraries</p></div><div id="content"><div id="module-header"><table class="info"><tr><th>Portability</th><td>non-portable</td></tr><tr><th>Stability</th><td>internal</td></tr><tr><th>Maintainer</th><td>libraries@haskell.org</td></tr></table><p class="caption">GHC.IO.Encoding.Types</p></div><div id="description"><p class="caption">Description</p><div class="doc"><p>Types for text encoding/decoding
</p></div></div><div id="synopsis"><p id="control.syn" class="caption expander" onclick="toggleSection('syn')">Synopsis</p><ul id="section.syn" class="hide" onclick="toggleSection('syn')"><li class="src short"><span class="keyword">data</span> <a href="#t:BufferCodec">BufferCodec</a> from to state = <a href="#v:BufferCodec">BufferCodec</a> {<ul class="subs"><li><a href="#v:encode">encode</a> :: <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> from -> <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> to -> <a href="System-IO.html#t:IO">IO</a> (<a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> from, <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> to)</li><li><a href="#v:close">close</a> :: <a href="System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Unit.html#t:-40--41-">()</a></li><li><a href="#v:getState">getState</a> :: <a href="System-IO.html#t:IO">IO</a> state</li><li><a href="#v:setState">setState</a> :: state -> <a href="System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Unit.html#t:-40--41-">()</a></li></ul>}</li><li class="src short"><span class="keyword">data</span> <a href="#t:TextEncoding">TextEncoding</a> = <span class="keyword">forall</span> dstate estate . <a href="#v:TextEncoding">TextEncoding</a> {<ul class="subs"><li><a href="#v:textEncodingName">textEncodingName</a> :: <a href="Data-Char.html#t:String">String</a></li><li><a href="#v:mkTextDecoder">mkTextDecoder</a> :: <a href="System-IO.html#t:IO">IO</a> (<a href="GHC-IO-Encoding-Types.html#t:TextDecoder">TextDecoder</a> dstate)</li><li><a href="#v:mkTextEncoder">mkTextEncoder</a> :: <a href="System-IO.html#t:IO">IO</a> (<a href="GHC-IO-Encoding-Types.html#t:TextEncoder">TextEncoder</a> estate)</li></ul>}</li><li class="src short"><span class="keyword">type</span> <a href="#t:TextEncoder">TextEncoder</a> state = <a href="GHC-IO-Encoding-Types.html#t:BufferCodec">BufferCodec</a> <a href="GHC-IO-Buffer.html#t:CharBufElem">CharBufElem</a> <a href="Data-Word.html#t:Word8">Word8</a> state</li><li class="src short"><span class="keyword">type</span> <a href="#t:TextDecoder">TextDecoder</a> state = <a href="GHC-IO-Encoding-Types.html#t:BufferCodec">BufferCodec</a> <a href="Data-Word.html#t:Word8">Word8</a> <a href="GHC-IO-Buffer.html#t:CharBufElem">CharBufElem</a> state</li><li class="src short"><span class="keyword">type</span> <a href="#t:EncodeBuffer">EncodeBuffer</a> = <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Char.html#t:Char">Char</a> -> <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Word.html#t:Word8">Word8</a> -> <a href="System-IO.html#t:IO">IO</a> (<a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Char.html#t:Char">Char</a>, <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Word.html#t:Word8">Word8</a>)</li><li class="src short"><span class="keyword">type</span> <a href="#t:DecodeBuffer">DecodeBuffer</a> = <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Word.html#t:Word8">Word8</a> -> <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Char.html#t:Char">Char</a> -> <a href="System-IO.html#t:IO">IO</a> (<a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Word.html#t:Word8">Word8</a>, <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Char.html#t:Char">Char</a>)</li></ul></div><div id="interface"><h1>Documentation</h1><div class="top"><p class="src"><span class="keyword">data</span> <a name="t:BufferCodec" class="def">BufferCodec</a> from to state <a href="src/GHC-IO-Encoding-Types.html#BufferCodec" class="link">Source</a></p><div class="subs constructors"><p class="caption">Constructors</p><table><tr><td class="src"><a name="v:BufferCodec" class="def">BufferCodec</a></td><td class="doc empty"> </td></tr><tr><td colspan="2"><div class="subs fields"><p class="caption">Fields</p><dl><dt class="src"><a name="v:encode" class="def">encode</a> :: <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> from -> <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> to -> <a href="System-IO.html#t:IO">IO</a> (<a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> from, <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> to)</dt><dd class="doc"><p>The <code>encode</code> function translates elements of the buffer <code>from</code>
to the buffer <code>to</code>. It should translate as many elements as possible
given the sizes of the buffers, including translating zero elements
if there is either not enough room in <code>to</code>, or <code>from</code> does not
contain a complete multibyte sequence.
</p><p><code>encode</code> should raise an exception if, and only if, <code>from</code>
begins with an illegal sequence, or the first element of <code>from</code>
is not representable in the encoding of <code>to</code>. That is, if any
elements can be successfully translated before an error is
encountered, then <code>encode</code> should translate as much as it can
and not throw an exception. This behaviour is used by the IO
library in order to report translation errors at the point they
actually occur, rather than when the buffer is translated.
</p></dd><dt class="src"><a name="v:close" class="def">close</a> :: <a href="System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Unit.html#t:-40--41-">()</a></dt><dd class="doc"><p>Resources associated with the encoding may now be released.
The <code>encode</code> function may not be called again after calling
<code>close</code>.
</p></dd><dt class="src"><a name="v:getState" class="def">getState</a> :: <a href="System-IO.html#t:IO">IO</a> state</dt><dd class="doc"><p>Return the current state of the codec.
</p><p>Many codecs are not stateful, and in these case the state can be
represented as '()'. Other codecs maintain a state. For
example, UTF-16 recognises a BOM (byte-order-mark) character at
the beginning of the input, and remembers thereafter whether to
use big-endian or little-endian mode. In this case, the state
of the codec would include two pieces of information: whether we
are at the beginning of the stream (the BOM only occurs at the
beginning), and if not, whether to use the big or little-endian
encoding.
</p></dd><dt class="src"><a name="v:setState" class="def">setState</a> :: state -> <a href="System-IO.html#t:IO">IO</a> <a href="../ghc-prim-0.2.0.0/GHC-Unit.html#t:-40--41-">()</a></dt><dd class="doc empty"> </dd></dl><div class="clear"></div></div></td></tr></table></div></div><div class="top"><p class="src"><span class="keyword">data</span> <a name="t:TextEncoding" class="def">TextEncoding</a> <a href="src/GHC-IO-Encoding-Types.html#TextEncoding" class="link">Source</a></p><div class="doc"><p>A <code><a href="GHC-IO-Encoding-Types.html#t:TextEncoding">TextEncoding</a></code> is a specification of a conversion scheme
between sequences of bytes and sequences of Unicode characters.
</p><p>For example, UTF-8 is an encoding of Unicode characters into a sequence
of bytes. The <code><a href="GHC-IO-Encoding-Types.html#t:TextEncoding">TextEncoding</a></code> for UTF-8 is <code>utf8</code>.
</p></div><div class="subs constructors"><p class="caption">Constructors</p><table><tr><td class="src"><span class="keyword">forall</span> dstate estate . <a name="v:TextEncoding" class="def">TextEncoding</a></td><td class="doc empty"> </td></tr><tr><td colspan="2"><div class="subs fields"><p class="caption">Fields</p><dl><dt class="src"><a name="v:textEncodingName" class="def">textEncodingName</a> :: <a href="Data-Char.html#t:String">String</a></dt><dd class="doc"><p>a string that can be passed to <code>mkTextEncoding</code> to
create an equivalent <code><a href="GHC-IO-Encoding-Types.html#t:TextEncoding">TextEncoding</a></code>.
</p></dd><dt class="src"><a name="v:mkTextDecoder" class="def">mkTextDecoder</a> :: <a href="System-IO.html#t:IO">IO</a> (<a href="GHC-IO-Encoding-Types.html#t:TextDecoder">TextDecoder</a> dstate)</dt><dd class="doc empty"> </dd><dt class="src"><a name="v:mkTextEncoder" class="def">mkTextEncoder</a> :: <a href="System-IO.html#t:IO">IO</a> (<a href="GHC-IO-Encoding-Types.html#t:TextEncoder">TextEncoder</a> estate)</dt><dd class="doc empty"> </dd></dl><div class="clear"></div></div></td></tr></table></div><div class="subs instances"><p id="control.i:TextEncoding" class="caption collapser" onclick="toggleSection('i:TextEncoding')">Instances</p><div id="section.i:TextEncoding" class="show"><table><tr><td class="src"><a href="Text-Show.html#t:Show">Show</a> <a href="GHC-IO-Encoding-Types.html#t:TextEncoding">TextEncoding</a></td><td class="doc empty"> </td></tr></table></div></div></div><div class="top"><p class="src"><span class="keyword">type</span> <a name="t:TextEncoder" class="def">TextEncoder</a> state = <a href="GHC-IO-Encoding-Types.html#t:BufferCodec">BufferCodec</a> <a href="GHC-IO-Buffer.html#t:CharBufElem">CharBufElem</a> <a href="Data-Word.html#t:Word8">Word8</a> state<a href="src/GHC-IO-Encoding-Types.html#TextEncoder" class="link">Source</a></p></div><div class="top"><p class="src"><span class="keyword">type</span> <a name="t:TextDecoder" class="def">TextDecoder</a> state = <a href="GHC-IO-Encoding-Types.html#t:BufferCodec">BufferCodec</a> <a href="Data-Word.html#t:Word8">Word8</a> <a href="GHC-IO-Buffer.html#t:CharBufElem">CharBufElem</a> state<a href="src/GHC-IO-Encoding-Types.html#TextDecoder" class="link">Source</a></p></div><div class="top"><p class="src"><span class="keyword">type</span> <a name="t:EncodeBuffer" class="def">EncodeBuffer</a> = <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Char.html#t:Char">Char</a> -> <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Word.html#t:Word8">Word8</a> -> <a href="System-IO.html#t:IO">IO</a> (<a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Char.html#t:Char">Char</a>, <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Word.html#t:Word8">Word8</a>)<a href="src/GHC-IO-Encoding-Types.html#EncodeBuffer" class="link">Source</a></p></div><div class="top"><p class="src"><span class="keyword">type</span> <a name="t:DecodeBuffer" class="def">DecodeBuffer</a> = <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Word.html#t:Word8">Word8</a> -> <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Char.html#t:Char">Char</a> -> <a href="System-IO.html#t:IO">IO</a> (<a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Word.html#t:Word8">Word8</a>, <a href="GHC-IO-Buffer.html#t:Buffer">Buffer</a> <a href="Data-Char.html#t:Char">Char</a>)<a href="src/GHC-IO-Encoding-Types.html#DecodeBuffer" class="link">Source</a></p></div></div></div><div id="footer"><p>Produced by <a href="http://www.haskell.org/haddock/">Haddock</a> version 2.9.2</p></div></body></html>
