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<pre><a name="line-1"></a><span class='hs-comment'>{- arch-tag: HVFS instance helpers
<a name="line-2"></a>Copyright (C) 2004 John Goerzen <jgoerzen@complete.org>
<a name="line-3"></a>
<a name="line-4"></a>This program is free software; you can redistribute it and/or modify
<a name="line-5"></a>it under the terms of the GNU General Public License as published by
<a name="line-6"></a>the Free Software Foundation; either version 2 of the License, or
<a name="line-7"></a>(at your option) any later version.
<a name="line-8"></a>
<a name="line-9"></a>This program is distributed in the hope that it will be useful,
<a name="line-10"></a>but WITHOUT ANY WARRANTY; without even the implied warranty of
<a name="line-11"></a>MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
<a name="line-12"></a>GNU General Public License for more details.
<a name="line-13"></a>
<a name="line-14"></a>You should have received a copy of the GNU General Public License
<a name="line-15"></a>along with this program; if not, write to the Free Software
<a name="line-16"></a>Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
<a name="line-17"></a>-}</span>
<a name="line-18"></a>
<a name="line-19"></a><span class='hs-comment'>{- |
<a name="line-20"></a> Module : System.IO.HVFS.InstanceHelpers
<a name="line-21"></a> Copyright : Copyright (C) 2004 John Goerzen
<a name="line-22"></a> License : GNU GPL, version 2 or above
<a name="line-23"></a>
<a name="line-24"></a> Maintainer : John Goerzen <jgoerzen@complete.org>
<a name="line-25"></a> Stability : provisional
<a name="line-26"></a> Portability: portable
<a name="line-27"></a>
<a name="line-28"></a>Utilities for creating instances of the items defined in
<a name="line-29"></a>"System.IO.HVFS".
<a name="line-30"></a>
<a name="line-31"></a>Copyright (c) 2004 John Goerzen, jgoerzen\@complete.org
<a name="line-32"></a>-}</span>
<a name="line-33"></a>
<a name="line-34"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span><span class='hs-varop'>.</span><span class='hs-conid'>HVFS</span><span class='hs-varop'>.</span><span class='hs-conid'>InstanceHelpers</span><span class='hs-layout'>(</span><span class='hs-comment'>-- * HVFSStat objects</span>
<a name="line-35"></a> <span class='hs-conid'>SimpleStat</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span>
<a name="line-36"></a> <span class='hs-comment'>-- * HVFS objects & types</span>
<a name="line-37"></a> <span class='hs-comment'>-- ** MemoryVFS</span>
<a name="line-38"></a> <span class='hs-conid'>MemoryVFS</span><span class='hs-layout'>,</span>
<a name="line-39"></a> <span class='hs-varid'>newMemoryVFS</span><span class='hs-layout'>,</span> <span class='hs-varid'>newMemoryVFSRef</span><span class='hs-layout'>,</span>
<a name="line-40"></a> <span class='hs-conid'>MemoryNode</span><span class='hs-layout'>,</span>
<a name="line-41"></a> <span class='hs-conid'>MemoryEntry</span><span class='hs-layout'>(</span><span class='hs-keyglyph'>..</span><span class='hs-layout'>)</span><span class='hs-layout'>,</span>
<a name="line-42"></a> <span class='hs-comment'>-- * Utilities</span>
<a name="line-43"></a> <span class='hs-varid'>nice_slice</span><span class='hs-layout'>,</span> <span class='hs-varid'>getFullPath</span><span class='hs-layout'>,</span>
<a name="line-44"></a> <span class='hs-varid'>getFullSlice</span><span class='hs-layout'>)</span>
<a name="line-45"></a> <span class='hs-keyword'>where</span>
<a name="line-46"></a>
<a name="line-47"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>IORef</span> <span class='hs-layout'>(</span><span class='hs-varid'>newIORef</span><span class='hs-layout'>,</span> <span class='hs-varid'>readIORef</span><span class='hs-layout'>,</span> <span class='hs-varid'>writeIORef</span><span class='hs-layout'>,</span> <span class='hs-conid'>IORef</span><span class='hs-conid'>()</span><span class='hs-layout'>)</span>
<a name="line-48"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>List</span> <span class='hs-layout'>(</span><span class='hs-varid'>genericLength</span><span class='hs-layout'>)</span>
<a name="line-49"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span> <span class='hs-comment'>-- (ReadMode)</span>
<a name="line-50"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span><span class='hs-varop'>.</span><span class='hs-conid'>Error</span> <span class='hs-layout'>(</span><span class='hs-varid'>doesNotExistErrorType</span><span class='hs-layout'>,</span> <span class='hs-varid'>illegalOperationErrorType</span><span class='hs-layout'>,</span> <span class='hs-varid'>permissionErrorType</span><span class='hs-layout'>)</span>
<a name="line-51"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span><span class='hs-varop'>.</span><span class='hs-conid'>HVFS</span>
<a name="line-52"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>IO</span><span class='hs-varop'>.</span><span class='hs-conid'>HVIO</span> <span class='hs-layout'>(</span><span class='hs-varid'>newStreamReader</span><span class='hs-layout'>)</span>
<a name="line-53"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Path</span> <span class='hs-layout'>(</span><span class='hs-varid'>absNormPath</span><span class='hs-layout'>)</span>
<a name="line-54"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Path</span><span class='hs-varop'>.</span><span class='hs-conid'>NameManip</span> <span class='hs-layout'>(</span><span class='hs-varid'>slice_path</span><span class='hs-layout'>)</span>
<a name="line-55"></a>
<a name="line-56"></a><a name="SimpleStat"></a><span class='hs-comment'>{- | A simple "System.IO.HVFS.HVFSStat"
<a name="line-57"></a>class that assumes that everything is either a file
<a name="line-58"></a>or a directory. -}</span>
<a name="line-59"></a><a name="SimpleStat"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>SimpleStat</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>SimpleStat</span> <span class='hs-layout'>{</span>
<a name="line-60"></a> <span class='hs-varid'>isFile</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>Bool</span><span class='hs-layout'>,</span> <span class='hs-comment'>-- ^ True if file, False if directory</span>
<a name="line-61"></a> <span class='hs-varid'>fileSize</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>FileOffset</span> <span class='hs-comment'>-- ^ Set to 0 if unknown or a directory</span>
<a name="line-62"></a> <span class='hs-layout'>}</span> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Show</span><span class='hs-layout'>,</span> <span class='hs-conid'>Eq</span><span class='hs-layout'>)</span>
<a name="line-63"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>HVFSStat</span> <span class='hs-conid'>SimpleStat</span> <span class='hs-keyword'>where</span>
<a name="line-64"></a> <span class='hs-varid'>vIsRegularFile</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>isFile</span> <span class='hs-varid'>x</span>
<a name="line-65"></a> <span class='hs-varid'>vIsDirectory</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>not</span> <span class='hs-layout'>(</span><span class='hs-varid'>isFile</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span>
<a name="line-66"></a> <span class='hs-varid'>vFileSize</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>fileSize</span> <span class='hs-varid'>x</span>
<a name="line-67"></a>
<a name="line-68"></a><a name="MemoryNode"></a><span class='hs-comment'>----------------------------------------------------------------------</span>
<a name="line-69"></a><a name="MemoryNode"></a><span class='hs-comment'>-- In-Memory Tree Types</span>
<a name="line-70"></a><a name="MemoryNode"></a><span class='hs-comment'>----------------------------------------------------------------------</span>
<a name="line-71"></a><a name="MemoryNode"></a><span class='hs-comment'>{- | The basic node of a 'MemoryVFS'. The String corresponds to the filename,
<a name="line-72"></a>and the entry to the contents. -}</span>
<a name="line-73"></a><a name="MemoryNode"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>MemoryNode</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-conid'>String</span><span class='hs-layout'>,</span> <span class='hs-conid'>MemoryEntry</span><span class='hs-layout'>)</span>
<a name="line-74"></a>
<a name="line-75"></a><a name="MemoryEntry"></a><span class='hs-comment'>{- | The content of a file or directory in a 'MemoryVFS'. -}</span>
<a name="line-76"></a><a name="MemoryEntry"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>MemoryEntry</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>MemoryDirectory</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>MemoryNode</span><span class='hs-keyglyph'>]</span>
<a name="line-77"></a> <span class='hs-keyglyph'>|</span> <span class='hs-conid'>MemoryFile</span> <span class='hs-conid'>String</span>
<a name="line-78"></a> <span class='hs-keyword'>deriving</span> <span class='hs-layout'>(</span><span class='hs-conid'>Eq</span><span class='hs-layout'>,</span> <span class='hs-conid'>Show</span><span class='hs-layout'>)</span>
<a name="line-79"></a>
<a name="line-80"></a><a name="MemoryVFS"></a><span class='hs-comment'>{- | An in-memory read\/write filesystem. Think of it as a dynamically
<a name="line-81"></a>resizable ramdisk written in Haskell. -}</span>
<a name="line-82"></a><a name="MemoryVFS"></a><span class='hs-keyword'>data</span> <span class='hs-conid'>MemoryVFS</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>MemoryVFS</span>
<a name="line-83"></a> <span class='hs-layout'>{</span> <span class='hs-varid'>content</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IORef</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>MemoryNode</span><span class='hs-keyglyph'>]</span><span class='hs-layout'>,</span>
<a name="line-84"></a> <span class='hs-varid'>cwd</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IORef</span> <span class='hs-conid'>FilePath</span>
<a name="line-85"></a> <span class='hs-layout'>}</span>
<a name="line-86"></a>
<a name="line-87"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>Show</span> <span class='hs-conid'>MemoryVFS</span> <span class='hs-keyword'>where</span>
<a name="line-88"></a> <span class='hs-varid'>show</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-str'>"<MemoryVFS>"</span>
<a name="line-89"></a>
<a name="line-90"></a><a name="newMemoryVFS"></a><span class='hs-comment'>-- | Create a new 'MemoryVFS' object from an existing tree.</span>
<a name="line-91"></a><span class='hs-comment'>-- An empty filesystem may be created by using @[]@ for the parameter.</span>
<a name="line-92"></a><span class='hs-definition'>newMemoryVFS</span> <span class='hs-keyglyph'>::</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>MemoryNode</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>MemoryVFS</span>
<a name="line-93"></a><span class='hs-definition'>newMemoryVFS</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>r</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>newIORef</span> <span class='hs-varid'>s</span>
<a name="line-94"></a> <span class='hs-varid'>newMemoryVFSRef</span> <span class='hs-varid'>r</span>
<a name="line-95"></a>
<a name="line-96"></a><a name="newMemoryVFSRef"></a><span class='hs-comment'>-- | Create a new 'MemoryVFS' object using an IORef to an</span>
<a name="line-97"></a><span class='hs-comment'>-- existing tree.</span>
<a name="line-98"></a><span class='hs-definition'>newMemoryVFSRef</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>IORef</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>MemoryNode</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>MemoryVFS</span>
<a name="line-99"></a><span class='hs-definition'>newMemoryVFSRef</span> <span class='hs-varid'>r</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-100"></a> <span class='hs-varid'>c</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>newIORef</span> <span class='hs-str'>"/"</span>
<a name="line-101"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-conid'>MemoryVFS</span> <span class='hs-layout'>{</span><span class='hs-varid'>content</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>r</span><span class='hs-layout'>,</span> <span class='hs-varid'>cwd</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>c</span><span class='hs-layout'>}</span><span class='hs-layout'>)</span>
<a name="line-102"></a>
<a name="line-103"></a><a name="nice_slice"></a><span class='hs-comment'>{- | Similar to 'System.Path.NameManip' but the first element
<a name="line-104"></a>won't be @\/@.
<a name="line-105"></a>
<a name="line-106"></a>>nice_slice "/" -> []
<a name="line-107"></a>>nice_slice "/foo/bar" -> ["foo", "bar"]
<a name="line-108"></a>-}</span>
<a name="line-109"></a><span class='hs-definition'>nice_slice</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>String</span><span class='hs-keyglyph'>]</span>
<a name="line-110"></a><span class='hs-definition'>nice_slice</span> <span class='hs-str'>"/"</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>[]</span>
<a name="line-111"></a><span class='hs-definition'>nice_slice</span> <span class='hs-varid'>path</span> <span class='hs-keyglyph'>=</span>
<a name="line-112"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>sliced1</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>slice_path</span> <span class='hs-varid'>path</span>
<a name="line-113"></a> <span class='hs-varid'>h</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>head</span> <span class='hs-varid'>sliced1</span>
<a name="line-114"></a> <span class='hs-varid'>t</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>tail</span> <span class='hs-varid'>sliced1</span>
<a name="line-115"></a> <span class='hs-varid'>newh</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>if</span> <span class='hs-varid'>head</span> <span class='hs-varid'>h</span> <span class='hs-varop'>==</span> <span class='hs-chr'>'/'</span> <span class='hs-keyword'>then</span> <span class='hs-varid'>tail</span> <span class='hs-varid'>h</span> <span class='hs-keyword'>else</span> <span class='hs-varid'>h</span>
<a name="line-116"></a> <span class='hs-varid'>sliced2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>newh</span> <span class='hs-conop'>:</span> <span class='hs-varid'>t</span>
<a name="line-117"></a> <span class='hs-keyword'>in</span> <span class='hs-varid'>sliced2</span>
<a name="line-118"></a>
<a name="line-119"></a><a name="getFullPath"></a><span class='hs-comment'>{- | Gets a full path, after investigating the cwd.
<a name="line-120"></a>-}</span>
<a name="line-121"></a><span class='hs-definition'>getFullPath</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>HVFS</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>String</span>
<a name="line-122"></a><span class='hs-definition'>getFullPath</span> <span class='hs-varid'>fs</span> <span class='hs-varid'>path</span> <span class='hs-keyglyph'>=</span>
<a name="line-123"></a> <span class='hs-keyword'>do</span> <span class='hs-varid'>cwd</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>vGetCurrentDirectory</span> <span class='hs-varid'>fs</span>
<a name="line-124"></a> <span class='hs-keyword'>case</span> <span class='hs-layout'>(</span><span class='hs-varid'>absNormPath</span> <span class='hs-varid'>cwd</span> <span class='hs-varid'>path</span><span class='hs-layout'>)</span> <span class='hs-keyword'>of</span>
<a name="line-125"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>vRaiseError</span> <span class='hs-varid'>fs</span> <span class='hs-varid'>doesNotExistErrorType</span>
<a name="line-126"></a> <span class='hs-layout'>(</span><span class='hs-str'>"Trouble normalizing path "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>path</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-layout'>(</span><span class='hs-varid'>cwd</span> <span class='hs-varop'>++</span> <span class='hs-str'>"/"</span> <span class='hs-varop'>++</span> <span class='hs-varid'>path</span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-127"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>newpath</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varid'>newpath</span>
<a name="line-128"></a>
<a name="line-129"></a><a name="getFullSlice"></a><span class='hs-comment'>{- | Gets the full path via 'getFullPath', then splits it via 'nice_slice'.
<a name="line-130"></a>-}</span>
<a name="line-131"></a><span class='hs-definition'>getFullSlice</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>HVFS</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=></span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>String</span><span class='hs-keyglyph'>]</span>
<a name="line-132"></a><span class='hs-definition'>getFullSlice</span> <span class='hs-varid'>fs</span> <span class='hs-varid'>fp</span> <span class='hs-keyglyph'>=</span>
<a name="line-133"></a> <span class='hs-keyword'>do</span> <span class='hs-varid'>newpath</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getFullPath</span> <span class='hs-varid'>fs</span> <span class='hs-varid'>fp</span>
<a name="line-134"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-varid'>nice_slice</span> <span class='hs-varid'>newpath</span><span class='hs-layout'>)</span>
<a name="line-135"></a>
<a name="line-136"></a><a name="findMelem"></a><span class='hs-comment'>-- | Find an element on the tree, assuming a normalized path</span>
<a name="line-137"></a><span class='hs-definition'>findMelem</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>MemoryVFS</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>MemoryEntry</span>
<a name="line-138"></a><span class='hs-definition'>findMelem</span> <span class='hs-varid'>x</span> <span class='hs-str'>"/"</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>readIORef</span> <span class='hs-layout'>(</span><span class='hs-varid'>content</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-varop'>>>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>.</span> <span class='hs-conid'>MemoryDirectory</span>
<a name="line-139"></a><span class='hs-definition'>findMelem</span> <span class='hs-varid'>x</span> <span class='hs-varid'>path</span> <span class='hs-keyglyph'>=</span>
<a name="line-140"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>sliced1</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>slice_path</span> <span class='hs-varid'>path</span>
<a name="line-141"></a> <span class='hs-varid'>h</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>head</span> <span class='hs-varid'>sliced1</span>
<a name="line-142"></a> <span class='hs-varid'>t</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>tail</span> <span class='hs-varid'>sliced1</span>
<a name="line-143"></a> <span class='hs-varid'>newh</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>if</span> <span class='hs-layout'>(</span><span class='hs-varid'>h</span> <span class='hs-varop'>/=</span> <span class='hs-str'>"/"</span><span class='hs-layout'>)</span> <span class='hs-varop'>&&</span> <span class='hs-varid'>head</span> <span class='hs-varid'>h</span> <span class='hs-varop'>==</span> <span class='hs-chr'>'/'</span> <span class='hs-keyword'>then</span> <span class='hs-varid'>tail</span> <span class='hs-varid'>h</span> <span class='hs-keyword'>else</span> <span class='hs-varid'>h</span>
<a name="line-144"></a> <span class='hs-varid'>sliced2</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>newh</span> <span class='hs-conop'>:</span> <span class='hs-varid'>t</span>
<a name="line-145"></a>
<a name="line-146"></a> <span class='hs-comment'>-- Walk the tree</span>
<a name="line-147"></a> <span class='hs-varid'>walk</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>MemoryEntry</span> <span class='hs-keyglyph'>-></span> <span class='hs-keyglyph'>[</span><span class='hs-conid'>String</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Either</span> <span class='hs-conid'>String</span> <span class='hs-conid'>MemoryEntry</span>
<a name="line-148"></a> <span class='hs-comment'>-- Empty list -- return the item we have</span>
<a name="line-149"></a> <span class='hs-varid'>walk</span> <span class='hs-varid'>y</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Right</span> <span class='hs-varid'>y</span>
<a name="line-150"></a> <span class='hs-comment'>-- Root directory -- return the item we have</span>
<a name="line-151"></a> <span class='hs-varid'>walk</span> <span class='hs-varid'>y</span> <span class='hs-keyglyph'>[</span><span class='hs-str'>"/"</span><span class='hs-keyglyph'>]</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>Right</span> <span class='hs-varid'>y</span>
<a name="line-152"></a> <span class='hs-comment'>-- File but stuff: error</span>
<a name="line-153"></a> <span class='hs-varid'>walk</span> <span class='hs-layout'>(</span><span class='hs-conid'>MemoryFile</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>z</span> <span class='hs-conop'>:</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-154"></a> <span class='hs-conid'>Left</span> <span class='hs-varop'>$</span> <span class='hs-str'>"Attempt to look up name "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>z</span> <span class='hs-varop'>++</span> <span class='hs-str'>" in file"</span>
<a name="line-155"></a> <span class='hs-varid'>walk</span> <span class='hs-layout'>(</span><span class='hs-conid'>MemoryDirectory</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>z</span> <span class='hs-conop'>:</span> <span class='hs-varid'>zs</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-156"></a> <span class='hs-keyword'>let</span> <span class='hs-varid'>newentry</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>case</span> <span class='hs-varid'>lookup</span> <span class='hs-varid'>z</span> <span class='hs-varid'>y</span> <span class='hs-keyword'>of</span>
<a name="line-157"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Left</span> <span class='hs-varop'>$</span> <span class='hs-str'>"Couldn't find entry "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>z</span>
<a name="line-158"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>Right</span> <span class='hs-varid'>a</span>
<a name="line-159"></a> <span class='hs-keyword'>in</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>newobj</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>newentry</span>
<a name="line-160"></a> <span class='hs-varid'>walk</span> <span class='hs-varid'>newobj</span> <span class='hs-varid'>zs</span>
<a name="line-161"></a> <span class='hs-keyword'>in</span> <span class='hs-keyword'>do</span>
<a name="line-162"></a> <span class='hs-varid'>c</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>readIORef</span> <span class='hs-varop'>$</span> <span class='hs-varid'>content</span> <span class='hs-varid'>x</span>
<a name="line-163"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>walk</span> <span class='hs-layout'>(</span><span class='hs-conid'>MemoryDirectory</span> <span class='hs-varid'>c</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-varid'>sliced2</span><span class='hs-layout'>)</span> <span class='hs-keyword'>of</span>
<a name="line-164"></a> <span class='hs-conid'>Left</span> <span class='hs-varid'>err</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>vRaiseError</span> <span class='hs-varid'>x</span> <span class='hs-varid'>doesNotExistErrorType</span> <span class='hs-varid'>err</span> <span class='hs-conid'>Nothing</span>
<a name="line-165"></a> <span class='hs-conid'>Right</span> <span class='hs-varid'>result</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varid'>result</span>
<a name="line-166"></a>
<a name="line-167"></a><a name="getMelem"></a><span class='hs-comment'>-- | Find an element on the tree, normalizing the path first</span>
<a name="line-168"></a><span class='hs-definition'>getMelem</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>MemoryVFS</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>MemoryEntry</span>
<a name="line-169"></a><span class='hs-definition'>getMelem</span> <span class='hs-varid'>x</span> <span class='hs-varid'>s</span> <span class='hs-keyglyph'>=</span>
<a name="line-170"></a> <span class='hs-keyword'>do</span> <span class='hs-varid'>base</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>readIORef</span> <span class='hs-varop'>$</span> <span class='hs-varid'>cwd</span> <span class='hs-varid'>x</span>
<a name="line-171"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>absNormPath</span> <span class='hs-varid'>base</span> <span class='hs-varid'>s</span> <span class='hs-keyword'>of</span>
<a name="line-172"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>vRaiseError</span> <span class='hs-varid'>x</span> <span class='hs-varid'>doesNotExistErrorType</span>
<a name="line-173"></a> <span class='hs-layout'>(</span><span class='hs-str'>"Trouble normalizing path "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>s</span><span class='hs-layout'>)</span>
<a name="line-174"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>newpath</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>findMelem</span> <span class='hs-varid'>x</span> <span class='hs-varid'>newpath</span>
<a name="line-175"></a>
<a name="line-176"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>HVFS</span> <span class='hs-conid'>MemoryVFS</span> <span class='hs-keyword'>where</span>
<a name="line-177"></a> <span class='hs-varid'>vGetCurrentDirectory</span> <span class='hs-varid'>x</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>readIORef</span> <span class='hs-varop'>$</span> <span class='hs-varid'>cwd</span> <span class='hs-varid'>x</span>
<a name="line-178"></a> <span class='hs-varid'>vSetCurrentDirectory</span> <span class='hs-varid'>x</span> <span class='hs-varid'>fp</span> <span class='hs-keyglyph'>=</span>
<a name="line-179"></a> <span class='hs-keyword'>do</span> <span class='hs-varid'>curpath</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>vGetCurrentDirectory</span> <span class='hs-varid'>x</span>
<a name="line-180"></a> <span class='hs-comment'>-- Make sure new dir is valid</span>
<a name="line-181"></a> <span class='hs-varid'>newdir</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getMelem</span> <span class='hs-varid'>x</span> <span class='hs-varid'>fp</span>
<a name="line-182"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>newdir</span> <span class='hs-keyword'>of</span>
<a name="line-183"></a> <span class='hs-layout'>(</span><span class='hs-conid'>MemoryFile</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>vRaiseError</span> <span class='hs-varid'>x</span> <span class='hs-varid'>doesNotExistErrorType</span>
<a name="line-184"></a> <span class='hs-layout'>(</span><span class='hs-str'>"Attempt to cwd to non-directory "</span> <span class='hs-varop'>++</span> <span class='hs-varid'>fp</span><span class='hs-layout'>)</span>
<a name="line-185"></a> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>fp</span><span class='hs-layout'>)</span>
<a name="line-186"></a> <span class='hs-layout'>(</span><span class='hs-conid'>MemoryDirectory</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span>
<a name="line-187"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>absNormPath</span> <span class='hs-varid'>curpath</span> <span class='hs-varid'>fp</span> <span class='hs-keyword'>of</span>
<a name="line-188"></a> <span class='hs-conid'>Nothing</span> <span class='hs-keyglyph'>-></span> <span class='hs-comment'>-- should never happen due to above getMelem call</span>
<a name="line-189"></a> <span class='hs-varid'>vRaiseError</span> <span class='hs-varid'>x</span> <span class='hs-varid'>illegalOperationErrorType</span>
<a name="line-190"></a> <span class='hs-str'>"Bad internal error"</span> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>fp</span><span class='hs-layout'>)</span>
<a name="line-191"></a> <span class='hs-conid'>Just</span> <span class='hs-varid'>y</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>writeIORef</span> <span class='hs-layout'>(</span><span class='hs-varid'>cwd</span> <span class='hs-varid'>x</span><span class='hs-layout'>)</span> <span class='hs-varid'>y</span>
<a name="line-192"></a> <span class='hs-varid'>vGetFileStatus</span> <span class='hs-varid'>x</span> <span class='hs-varid'>fp</span> <span class='hs-keyglyph'>=</span>
<a name="line-193"></a> <span class='hs-keyword'>do</span> <span class='hs-varid'>elem</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getMelem</span> <span class='hs-varid'>x</span> <span class='hs-varid'>fp</span>
<a name="line-194"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>elem</span> <span class='hs-keyword'>of</span>
<a name="line-195"></a> <span class='hs-layout'>(</span><span class='hs-conid'>MemoryFile</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>HVFSStatEncap</span> <span class='hs-varop'>$</span>
<a name="line-196"></a> <span class='hs-conid'>SimpleStat</span> <span class='hs-layout'>{</span><span class='hs-varid'>isFile</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>True</span><span class='hs-layout'>,</span>
<a name="line-197"></a> <span class='hs-varid'>fileSize</span> <span class='hs-keyglyph'>=</span> <span class='hs-layout'>(</span><span class='hs-varid'>genericLength</span> <span class='hs-varid'>y</span><span class='hs-layout'>)</span><span class='hs-layout'>}</span>
<a name="line-198"></a> <span class='hs-layout'>(</span><span class='hs-conid'>MemoryDirectory</span> <span class='hs-keyword'>_</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-conid'>HVFSStatEncap</span> <span class='hs-varop'>$</span>
<a name="line-199"></a> <span class='hs-conid'>SimpleStat</span> <span class='hs-layout'>{</span><span class='hs-varid'>isFile</span> <span class='hs-keyglyph'>=</span> <span class='hs-conid'>False</span><span class='hs-layout'>,</span>
<a name="line-200"></a> <span class='hs-varid'>fileSize</span> <span class='hs-keyglyph'>=</span> <span class='hs-num'>0</span><span class='hs-layout'>}</span>
<a name="line-201"></a> <span class='hs-varid'>vGetDirectoryContents</span> <span class='hs-varid'>x</span> <span class='hs-varid'>fp</span> <span class='hs-keyglyph'>=</span>
<a name="line-202"></a> <span class='hs-keyword'>do</span> <span class='hs-varid'>elem</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getMelem</span> <span class='hs-varid'>x</span> <span class='hs-varid'>fp</span>
<a name="line-203"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>elem</span> <span class='hs-keyword'>of</span>
<a name="line-204"></a> <span class='hs-conid'>MemoryFile</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>vRaiseError</span> <span class='hs-varid'>x</span> <span class='hs-varid'>doesNotExistErrorType</span>
<a name="line-205"></a> <span class='hs-str'>"Can't list contents of a file"</span>
<a name="line-206"></a> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>fp</span><span class='hs-layout'>)</span>
<a name="line-207"></a> <span class='hs-conid'>MemoryDirectory</span> <span class='hs-varid'>c</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-varid'>map</span> <span class='hs-varid'>fst</span> <span class='hs-varid'>c</span>
<a name="line-208"></a>
<a name="line-209"></a><span class='hs-keyword'>instance</span> <span class='hs-conid'>HVFSOpenable</span> <span class='hs-conid'>MemoryVFS</span> <span class='hs-keyword'>where</span>
<a name="line-210"></a> <span class='hs-varid'>vOpen</span> <span class='hs-varid'>x</span> <span class='hs-varid'>fp</span> <span class='hs-layout'>(</span><span class='hs-conid'>ReadMode</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>=</span>
<a name="line-211"></a> <span class='hs-keyword'>do</span> <span class='hs-varid'>elem</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>getMelem</span> <span class='hs-varid'>x</span> <span class='hs-varid'>fp</span>
<a name="line-212"></a> <span class='hs-keyword'>case</span> <span class='hs-varid'>elem</span> <span class='hs-keyword'>of</span>
<a name="line-213"></a> <span class='hs-conid'>MemoryDirectory</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>vRaiseError</span> <span class='hs-varid'>x</span> <span class='hs-varid'>doesNotExistErrorType</span>
<a name="line-214"></a> <span class='hs-str'>"Can't open a directory"</span>
<a name="line-215"></a> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>fp</span><span class='hs-layout'>)</span>
<a name="line-216"></a> <span class='hs-conid'>MemoryFile</span> <span class='hs-varid'>y</span> <span class='hs-keyglyph'>-></span> <span class='hs-varid'>newStreamReader</span> <span class='hs-varid'>y</span> <span class='hs-varop'>>>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>.</span> <span class='hs-conid'>HVFSOpenEncap</span>
<a name="line-217"></a> <span class='hs-varid'>vOpen</span> <span class='hs-varid'>x</span> <span class='hs-varid'>fp</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>vRaiseError</span> <span class='hs-varid'>x</span> <span class='hs-varid'>permissionErrorType</span>
<a name="line-218"></a> <span class='hs-str'>"Only ReadMode is supported with MemoryVFS files"</span>
<a name="line-219"></a> <span class='hs-layout'>(</span><span class='hs-conid'>Just</span> <span class='hs-varid'>fp</span><span class='hs-layout'>)</span>
<a name="line-220"></a>
</pre></body>
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