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<title>Data/Text/Lazy/Internal.hs</title>
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<pre><a name="line-1"></a><span class='hs-comment'>{-# LANGUAGE BangPatterns, DeriveDataTypeable #-}</span>
<a name="line-2"></a><span class='hs-comment'>-- |</span>
<a name="line-3"></a><span class='hs-comment'>-- Module : Data.Text.Lazy.Internal</span>
<a name="line-4"></a><span class='hs-comment'>-- Copyright : (c) 2009, 2010 Bryan O'Sullivan</span>
<a name="line-5"></a><span class='hs-comment'>--</span>
<a name="line-6"></a><span class='hs-comment'>-- License : BSD-style</span>
<a name="line-7"></a><span class='hs-comment'>-- Maintainer : bos@serpentine.com, rtomharper@googlemail.com,</span>
<a name="line-8"></a><span class='hs-comment'>-- duncan@haskell.org</span>
<a name="line-9"></a><span class='hs-comment'>-- Stability : experimental</span>
<a name="line-10"></a><span class='hs-comment'>-- Portability : GHC</span>
<a name="line-11"></a><span class='hs-comment'>-- </span>
<a name="line-12"></a><span class='hs-comment'>-- A module containing semi-public 'Text' internals. This exposes the</span>
<a name="line-13"></a><span class='hs-comment'>-- 'Text' representation and low level construction functions.</span>
<a name="line-14"></a><span class='hs-comment'>-- Modules which extend the 'Text' system may need to use this module.</span>
<a name="line-15"></a><span class='hs-comment'>-- Regular users should not.</span>
<a name="line-16"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span><span class='hs-varop'>.</span><span class='hs-conid'>Lazy</span><span class='hs-varop'>.</span><span class='hs-conid'>Internal</span>
<a name="line-17"></a> <span class='hs-layout'>(</span>
<a name="line-18"></a> <span class='hs-conid'>Text</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span>
<a name="line-19"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>chunk</span>
<a name="line-20"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>empty</span>
<a name="line-21"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>foldrChunks</span>
<a name="line-22"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>foldlChunks</span>
<a name="line-23"></a> <span class='hs-comment'>-- * Data type invariant and abstraction functions</span>
<a name="line-24"></a>
<a name="line-25"></a> <span class='hs-comment'>-- $invariant</span>
<a name="line-26"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>strictInvariant</span>
<a name="line-27"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>lazyInvariant</span>
<a name="line-28"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>showStructure</span>
<a name="line-29"></a>
<a name="line-30"></a> <span class='hs-comment'>-- * Chunk allocation sizes</span>
<a name="line-31"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>defaultChunkSize</span>
<a name="line-32"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>smallChunkSize</span>
<a name="line-33"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>chunkOverhead</span>
<a name="line-34"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-35"></a>
<a name="line-36"></a><span class='hs-keyword'>import</span> <span class='hs-keyword'>qualified</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span><span class='hs-varop'>.</span><span class='hs-conid'>Internal</span> <span class='hs-keyword'>as</span> <span class='hs-conid'>T</span>
<a name="line-37"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-conid'>()</span>
<a name="line-38"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span><span class='hs-varop'>.</span><span class='hs-conid'>UnsafeShift</span>
<a name="line-39"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Typeable</span> <span class='hs-layout'>(</span><span class='hs-conid'>Typeable</span><span class='hs-layout'>)</span>
<a name="line-40"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Foreign</span><span class='hs-varop'>.</span><span class='hs-conid'>Storable</span> <span class='hs-layout'>(</span><span class='hs-varid'>sizeOf</span><span class='hs-layout'>)</span>
<a name="line-41"></a>
<a name="line-42"></a><a name="Text"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>Text</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Empty</span>
<a name="line-43"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>Chunk</span> <span class='hs-comment'>{-# UNPACK #-}</span> <span class='hs-varop'>!</span><span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-conid'>Text</span>
<a name="line-44"></a> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Typeable</span><span class='hs-layout'>)</span>
<a name="line-45"></a>
<a name="line-46"></a><span class='hs-comment'>-- $invariant</span>
<a name="line-47"></a><span class='hs-comment'>--</span>
<a name="line-48"></a><span class='hs-comment'>-- The data type invariant for lazy 'Text': Every 'Text' is either 'Empty' or</span>
<a name="line-49"></a><span class='hs-comment'>-- consists of non-null 'T.Text's. All functions must preserve this,</span>
<a name="line-50"></a><span class='hs-comment'>-- and the QC properties must check this.</span>
<a name="line-51"></a>
<a name="line-52"></a><a name="strictInvariant"></a><span class='hs-comment'>-- | Check the invariant strictly.</span>
<a name="line-53"></a><span class='hs-definition'>strictInvariant</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Text</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Bool</span>
<a name="line-54"></a><span class='hs-definition'>strictInvariant</span> <span class='hs-conid'>Empty</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>True</span>
<a name="line-55"></a><span class='hs-definition'>strictInvariant</span> <span class='hs-varid'>x</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>Chunk</span> <span class='hs-layout'>(</span><span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>len</span><span class='hs-layout'>)</span> <span class='hs-varid'>cs</span><span class='hs-layout'>)</span>
<a name="line-56"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>len</span> <span class='hs-varop'>></span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>strictInvariant</span> <span class='hs-varid'>cs</span>
<a name="line-57"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>error</span> <span class='hs-varop'>$</span> <span class='hs-str'>"Data.Text.Lazy: invariant violation: "</span>
<a name="line-58"></a> <span class='hs-varop'>++</span> <span class='hs-varid'>showStructure</span> <span class='hs-varid'>x</span>
<a name="line-59"></a>
<a name="line-60"></a><a name="lazyInvariant"></a><span class='hs-comment'>-- | Check the invariant lazily.</span>
<a name="line-61"></a><span class='hs-definition'>lazyInvariant</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Text</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Text</span>
<a name="line-62"></a><span class='hs-definition'>lazyInvariant</span> <span class='hs-conid'>Empty</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Empty</span>
<a name="line-63"></a><span class='hs-definition'>lazyInvariant</span> <span class='hs-varid'>x</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>Chunk</span> <span class='hs-varid'>c</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>len</span><span class='hs-layout'>)</span> <span class='hs-varid'>cs</span><span class='hs-layout'>)</span>
<a name="line-64"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>len</span> <span class='hs-varop'>></span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Chunk</span> <span class='hs-varid'>c</span> <span class='hs-layout'>(</span><span class='hs-varid'>lazyInvariant</span> <span class='hs-varid'>cs</span><span class='hs-layout'>)</span>
<a name="line-65"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>error</span> <span class='hs-varop'>$</span> <span class='hs-str'>"Data.Text.Lazy: invariant violation: "</span>
<a name="line-66"></a> <span class='hs-varop'>++</span> <span class='hs-varid'>showStructure</span> <span class='hs-varid'>x</span>
<a name="line-67"></a>
<a name="line-68"></a><a name="showStructure"></a><span class='hs-comment'>-- | Display the internal structure of a lazy 'Text'.</span>
<a name="line-69"></a><span class='hs-definition'>showStructure</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Text</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span>
<a name="line-70"></a><span class='hs-definition'>showStructure</span> <span class='hs-conid'>Empty</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>"Empty"</span>
<a name="line-71"></a><span class='hs-definition'>showStructure</span> <span class='hs-layout'>(</span><span class='hs-conid'>Chunk</span> <span class='hs-varid'>t</span> <span class='hs-conid'>Empty</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>"Chunk "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>show</span> <span class='hs-varid'>t</span> <span class='hs-varop'>++</span> <span class='hs-str'>" Empty"</span>
<a name="line-72"></a><span class='hs-definition'>showStructure</span> <span class='hs-layout'>(</span><span class='hs-conid'>Chunk</span> <span class='hs-varid'>t</span> <span class='hs-varid'>ts</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-73"></a> <span class='hs-str'>"Chunk "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>show</span> <span class='hs-varid'>t</span> <span class='hs-varop'>++</span> <span class='hs-str'>" ("</span> <span class='hs-varop'>++</span> <span class='hs-varid'>showStructure</span> <span class='hs-varid'>ts</span> <span class='hs-varop'>++</span> <span class='hs-str'>")"</span>
<a name="line-74"></a>
<a name="line-75"></a><a name="chunk"></a><span class='hs-comment'>-- | Smart constructor for 'Chunk'. Guarantees the data type invariant.</span>
<a name="line-76"></a><span class='hs-definition'>chunk</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Text</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Text</span>
<a name="line-77"></a><span class='hs-comment'>{-# INLINE chunk #-}</span>
<a name="line-78"></a><span class='hs-definition'>chunk</span> <span class='hs-varid'>t</span><span class='hs-keyglyph'>@</span><span class='hs-layout'>(</span><span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-keyword'>_</span> <span class='hs-keyword'>_</span> <span class='hs-varid'>len</span><span class='hs-layout'>)</span> <span class='hs-varid'>ts</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>len</span> <span class='hs-varop'>==</span> <span class='hs-num'>0</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>ts</span>
<a name="line-79"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Chunk</span> <span class='hs-varid'>t</span> <span class='hs-varid'>ts</span>
<a name="line-80"></a>
<a name="line-81"></a><a name="empty"></a><span class='hs-comment'>-- | Smart constructor for 'Empty'.</span>
<a name="line-82"></a><span class='hs-definition'>empty</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Text</span>
<a name="line-83"></a><span class='hs-comment'>{-# INLINE [0] empty #-}</span>
<a name="line-84"></a><span class='hs-definition'>empty</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Empty</span>
<a name="line-85"></a>
<a name="line-86"></a><a name="foldrChunks"></a><span class='hs-comment'>-- | Consume the chunks of a lazy 'Text' with a natural right fold.</span>
<a name="line-87"></a><span class='hs-definition'>foldrChunks</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Text</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-88"></a><span class='hs-definition'>foldrChunks</span> <span class='hs-varid'>f</span> <span class='hs-varid'>z</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>go</span>
<a name="line-89"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>go</span> <span class='hs-conid'>Empty</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>z</span>
<a name="line-90"></a> <span class='hs-varid'>go</span> <span class='hs-layout'>(</span><span class='hs-conid'>Chunk</span> <span class='hs-varid'>c</span> <span class='hs-varid'>cs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>f</span> <span class='hs-varid'>c</span> <span class='hs-layout'>(</span><span class='hs-varid'>go</span> <span class='hs-varid'>cs</span><span class='hs-layout'>)</span>
<a name="line-91"></a><span class='hs-comment'>{-# INLINE foldrChunks #-}</span>
<a name="line-92"></a>
<a name="line-93"></a><a name="foldlChunks"></a><span class='hs-comment'>-- | Consume the chunks of a lazy 'Text' with a strict, tail-recursive,</span>
<a name="line-94"></a><span class='hs-comment'>-- accumulating left fold.</span>
<a name="line-95"></a><span class='hs-definition'>foldlChunks</span> <span class='hs-keyglyph'>::</span> <span class='hs-layout'>(</span><span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>T</span><span class='hs-varop'>.</span><span class='hs-conid'>Text</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Text</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>a</span>
<a name="line-96"></a><span class='hs-definition'>foldlChunks</span> <span class='hs-varid'>f</span> <span class='hs-varid'>z</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>go</span> <span class='hs-varid'>z</span>
<a name="line-97"></a> <span class='hs-keyword'>where</span> <span class='hs-varid'>go</span> <span class='hs-varop'>!</span><span class='hs-varid'>a</span> <span class='hs-conid'>Empty</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>a</span>
<a name="line-98"></a> <span class='hs-varid'>go</span> <span class='hs-varop'>!</span><span class='hs-varid'>a</span> <span class='hs-layout'>(</span><span class='hs-conid'>Chunk</span> <span class='hs-varid'>c</span> <span class='hs-varid'>cs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>go</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span> <span class='hs-varid'>a</span> <span class='hs-varid'>c</span><span class='hs-layout'>)</span> <span class='hs-varid'>cs</span>
<a name="line-99"></a><span class='hs-comment'>{-# INLINE foldlChunks #-}</span>
<a name="line-100"></a>
<a name="line-101"></a><a name="defaultChunkSize"></a><span class='hs-comment'>-- | Currently set to 16 KiB, less the memory management overhead.</span>
<a name="line-102"></a><span class='hs-definition'>defaultChunkSize</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span>
<a name="line-103"></a><span class='hs-definition'>defaultChunkSize</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>16384</span> <span class='hs-comment'>-</span> <span class='hs-varid'>chunkOverhead</span>
<a name="line-104"></a><span class='hs-comment'>{-# INLINE defaultChunkSize #-}</span>
<a name="line-105"></a>
<a name="line-106"></a><a name="smallChunkSize"></a><span class='hs-comment'>-- | Currently set to 128 bytes, less the memory management overhead.</span>
<a name="line-107"></a><span class='hs-definition'>smallChunkSize</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span>
<a name="line-108"></a><span class='hs-definition'>smallChunkSize</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>128</span> <span class='hs-comment'>-</span> <span class='hs-varid'>chunkOverhead</span>
<a name="line-109"></a><span class='hs-comment'>{-# INLINE smallChunkSize #-}</span>
<a name="line-110"></a>
<a name="line-111"></a><a name="chunkOverhead"></a><span class='hs-comment'>-- | The memory management overhead. Currently this is tuned for GHC only.</span>
<a name="line-112"></a><span class='hs-definition'>chunkOverhead</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span>
<a name="line-113"></a><span class='hs-definition'>chunkOverhead</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>sizeOf</span> <span class='hs-layout'>(</span><span class='hs-varid'>undefined</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Int</span><span class='hs-layout'>)</span> <span class='hs-varop'>`shiftL`</span> <span class='hs-num'>1</span>
<a name="line-114"></a><span class='hs-comment'>{-# INLINE chunkOverhead #-}</span>
</pre></body>
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