hxt-8.0.0: doc/hdoc/src/Text-XML-HXT-DOM-XmlState.html
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<pre><a name="line-1"></a><span class='comment'>-- |</span>
<a name="line-2"></a><span class='comment'>-- This module provides a Monad for an internal state and IO commands.</span>
<a name="line-3"></a><span class='comment'>-- The state consists of two parts, the user state and the system state</span>
<a name="line-4"></a><span class='comment'>-- user state ist a type parameter, the system state is a list</span>
<a name="line-5"></a><span class='comment'>-- name-value pair. If the user state is not needed, the type parameter</span>
<a name="line-6"></a><span class='comment'>-- can be instantiated with @()@.</span>
<a name="line-7"></a><span class='comment'>--</span>
<a name="line-8"></a><span class='comment'>-- Furthermore there are types for Xml filter working on this monad</span>
<a name="line-9"></a><span class='comment'>-- and functions for manipulating the state components</span>
<a name="line-10"></a><span class='comment'>-- and for lifting i\/o commands and XmlFilter to monad filters.</span>
<a name="line-11"></a><span class='comment'>--</span>
<a name="line-12"></a><span class='comment'>-- Error reporting functions are also located in this module.</span>
<a name="line-13"></a><span class='comment'>--</span>
<a name="line-14"></a><span class='comment'>-- Version : $Id: XmlState.hs,v 1.3 2005/05/27 13:15:23 hxml Exp $</span>
<a name="line-15"></a>
<a name="line-16"></a><span class='keyword'>module</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>DOM</span><span class='varop'>.</span><span class='conid'>XmlState</span>
<a name="line-17"></a> <span class='layout'>(</span> <span class='keyword'>module</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>DOM</span><span class='varop'>.</span><span class='conid'>XmlState</span>
<a name="line-18"></a> <span class='layout'>)</span>
<a name="line-19"></a><span class='keyword'>where</span>
<a name="line-20"></a>
<a name="line-21"></a><span class='keyword'>import</span> <span class='conid'>Text</span><span class='varop'>.</span><span class='conid'>XML</span><span class='varop'>.</span><span class='conid'>HXT</span><span class='varop'>.</span><span class='conid'>DOM</span><span class='varop'>.</span><span class='conid'>XmlTree</span>
<a name="line-22"></a>
<a name="line-23"></a><span class='keyword'>import</span> <span class='keyword'>qualified</span> <span class='conid'>Control</span><span class='varop'>.</span><span class='conid'>Monad</span><span class='varop'>.</span><span class='conid'>MonadStateIO</span> <span class='keyword'>as</span> <span class='conid'>MonadStateIO</span>
<a name="line-24"></a>
<a name="line-25"></a><span class='keyword'>import</span> <span class='conid'>System</span><span class='varop'>.</span><span class='conid'>IO</span>
<a name="line-26"></a><span class='keyword'>import</span> <span class='conid'>Data</span><span class='varop'>.</span><span class='conid'>Maybe</span>
<a name="line-27"></a>
<a name="line-28"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-29"></a>
<a name="line-30"></a><span class='comment'>-- |</span>
<a name="line-31"></a><span class='comment'>-- The internal system state consists of a list of name-value pairs</span>
<a name="line-32"></a><span class='comment'>-- of type @(String, XmlTrees)@, so arbitrary lists of trees can be stored.</span>
<a name="line-33"></a><span class='comment'>-- For options, often only strings are used as values, so a set of access</span>
<a name="line-34"></a><span class='comment'>-- functions with string values is available</span>
<a name="line-35"></a><span class='comment'>-- The error handling method can be controlled by an error handler filter,</span>
<a name="line-36"></a><span class='comment'>-- the default filter issues the errors on stderr</span>
<a name="line-37"></a>
<a name="line-38"></a><a name="SysState"></a><span class='keyword'>data</span> <span class='conid'>SysState</span> <span class='keyglyph'>=</span> <span class='conid'>SysState</span> <span class='layout'>{</span> <span class='varid'>sysStateAttrs</span> <span class='keyglyph'>::</span> <span class='varop'>!</span> <span class='conid'>SysStateAttrs</span>
<a name="line-39"></a> <span class='layout'>,</span> <span class='varid'>sysStateErrorHandler</span> <span class='keyglyph'>::</span> <span class='varop'>!</span> <span class='layout'>(</span><span class='conid'>XmlStateFilter</span> <span class='conid'>()</span><span class='layout'>)</span>
<a name="line-40"></a> <span class='layout'>}</span>
<a name="line-41"></a>
<a name="line-42"></a><a name="SysStateAttrs"></a><span class='keyword'>type</span> <span class='conid'>SysStateAttrs</span> <span class='keyglyph'>=</span> <span class='conid'>AssocList</span> <span class='conid'>String</span> <span class='conid'>XmlTrees</span>
<a name="line-43"></a>
<a name="line-44"></a><span class='comment'>-- |</span>
<a name="line-45"></a><span class='comment'>-- The State has a system and a user part</span>
<a name="line-46"></a><span class='comment'>-- the user state is a type parameter</span>
<a name="line-47"></a>
<a name="line-48"></a><a name="XmlState"></a><span class='keyword'>data</span> <span class='conid'>XmlState</span> <span class='varid'>state</span> <span class='keyglyph'>=</span> <span class='conid'>XmlState</span> <span class='layout'>{</span> <span class='varid'>sysState</span> <span class='keyglyph'>::</span> <span class='varop'>!</span> <span class='conid'>SysState</span>
<a name="line-49"></a> <span class='layout'>,</span> <span class='varid'>userState</span> <span class='keyglyph'>::</span> <span class='varop'>!</span> <span class='varid'>state</span>
<a name="line-50"></a> <span class='layout'>}</span>
<a name="line-51"></a>
<a name="line-52"></a><span class='comment'>-- |</span>
<a name="line-53"></a><span class='comment'>-- The monad type for commands. It is an instance of "StateIO" from the</span>
<a name="line-54"></a><span class='comment'>-- general module "Control.Monad.MonadStateIO".</span>
<a name="line-55"></a>
<a name="line-56"></a><a name="XState"></a><span class='keyword'>type</span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='varid'>res</span> <span class='keyglyph'>=</span> <span class='conid'>MonadStateIO</span><span class='varop'>.</span><span class='conid'>StateIO</span> <span class='layout'>(</span><span class='conid'>XmlState</span> <span class='varid'>state</span><span class='layout'>)</span> <span class='varid'>res</span>
<a name="line-57"></a>
<a name="line-58"></a><span class='comment'>-- |</span>
<a name="line-59"></a><span class='comment'>-- The "XmlFilter" type for filters working on a state</span>
<a name="line-60"></a>
<a name="line-61"></a><a name="XmlStateFilter"></a><span class='keyword'>type</span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span> <span class='keyglyph'>=</span> <span class='conid'>XmlTree</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>XmlTrees</span>
<a name="line-62"></a>
<a name="line-63"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-64"></a><span class='comment'>--</span>
<a name="line-65"></a><span class='comment'>-- user defined state</span>
<a name="line-66"></a><span class='comment'>-- access functions</span>
<a name="line-67"></a>
<a name="line-68"></a><span class='comment'>-- |</span>
<a name="line-69"></a><span class='comment'>-- change the user state</span>
<a name="line-70"></a><span class='comment'>--</span>
<a name="line-71"></a><span class='comment'>-- * 1.parameter fct : the user state change function</span>
<a name="line-72"></a><span class='comment'>--</span>
<a name="line-73"></a><span class='comment'>-- - returns : the new state</span>
<a name="line-74"></a>
<a name="line-75"></a><a name="changeState"></a><span class='definition'>changeState</span> <span class='keyglyph'>::</span> <span class='layout'>(</span><span class='varid'>state</span> <span class='keyglyph'>-></span> <span class='varid'>state</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='varid'>state</span>
<a name="line-76"></a><span class='definition'>changeState</span> <span class='varid'>f</span>
<a name="line-77"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-78"></a> <span class='varid'>ns</span> <span class='keyglyph'><-</span> <span class='conid'>MonadStateIO</span><span class='varop'>.</span><span class='varid'>changeState</span> <span class='varid'>f'</span>
<a name="line-79"></a> <span class='varid'>return</span> <span class='layout'>(</span><span class='varid'>userState</span> <span class='varid'>ns</span><span class='layout'>)</span>
<a name="line-80"></a> <span class='keyword'>where</span>
<a name="line-81"></a> <span class='varid'>f'</span> <span class='varid'>s</span> <span class='keyglyph'>=</span> <span class='varid'>s</span> <span class='layout'>{</span> <span class='varid'>userState</span> <span class='keyglyph'>=</span> <span class='varid'>f</span> <span class='layout'>(</span><span class='varid'>userState</span> <span class='varid'>s</span><span class='layout'>)</span> <span class='layout'>}</span>
<a name="line-82"></a>
<a name="line-83"></a><span class='comment'>-- |</span>
<a name="line-84"></a><span class='comment'>-- set the user state.</span>
<a name="line-85"></a><span class='comment'>--</span>
<a name="line-86"></a><span class='comment'>-- * 1.parameter s : the new state</span>
<a name="line-87"></a><span class='comment'>--</span>
<a name="line-88"></a><span class='comment'>-- - returns : the new state</span>
<a name="line-89"></a>
<a name="line-90"></a><a name="setState"></a><span class='definition'>setState</span> <span class='keyglyph'>::</span> <span class='varid'>state</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='varid'>state</span>
<a name="line-91"></a><span class='definition'>setState</span> <span class='varid'>s</span>
<a name="line-92"></a> <span class='keyglyph'>=</span> <span class='varid'>changeState</span> <span class='layout'>(</span> <span class='keyglyph'>\</span><span class='keyword'>_</span> <span class='keyglyph'>-></span> <span class='varid'>s</span> <span class='layout'>)</span>
<a name="line-93"></a>
<a name="line-94"></a><span class='comment'>-- |</span>
<a name="line-95"></a><span class='comment'>-- read the user state</span>
<a name="line-96"></a><span class='comment'>--</span>
<a name="line-97"></a><span class='comment'>-- - returns : the current state</span>
<a name="line-98"></a>
<a name="line-99"></a><a name="getState"></a><span class='definition'>getState</span> <span class='keyglyph'>::</span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='varid'>state</span>
<a name="line-100"></a><span class='definition'>getState</span>
<a name="line-101"></a> <span class='keyglyph'>=</span> <span class='varid'>changeState</span> <span class='varid'>id</span>
<a name="line-102"></a>
<a name="line-103"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-104"></a>
<a name="line-105"></a><span class='comment'>-- |</span>
<a name="line-106"></a><span class='comment'>-- change the system part of the state.</span>
<a name="line-107"></a><span class='comment'>--</span>
<a name="line-108"></a><span class='comment'>-- see also : 'changeState'</span>
<a name="line-109"></a>
<a name="line-110"></a><a name="changeSysState"></a><span class='definition'>changeSysState</span> <span class='keyglyph'>::</span> <span class='layout'>(</span><span class='conid'>SysState</span> <span class='keyglyph'>-></span> <span class='conid'>SysState</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>SysState</span>
<a name="line-111"></a><span class='definition'>changeSysState</span> <span class='varid'>f</span>
<a name="line-112"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-113"></a> <span class='varid'>ns</span> <span class='keyglyph'><-</span> <span class='conid'>MonadStateIO</span><span class='varop'>.</span><span class='varid'>changeState</span> <span class='varid'>f'</span>
<a name="line-114"></a> <span class='varid'>return</span> <span class='layout'>(</span><span class='varid'>sysState</span> <span class='varid'>ns</span><span class='layout'>)</span>
<a name="line-115"></a> <span class='keyword'>where</span>
<a name="line-116"></a> <span class='varid'>f'</span> <span class='varid'>s</span> <span class='keyglyph'>=</span> <span class='varid'>s</span> <span class='layout'>{</span> <span class='varid'>sysState</span> <span class='keyglyph'>=</span> <span class='varid'>f</span> <span class='layout'>(</span><span class='varid'>sysState</span> <span class='varid'>s</span><span class='layout'>)</span> <span class='layout'>}</span>
<a name="line-117"></a>
<a name="line-118"></a><span class='comment'>-- |</span>
<a name="line-119"></a><span class='comment'>-- set the system part of the state.</span>
<a name="line-120"></a><span class='comment'>--</span>
<a name="line-121"></a><span class='comment'>-- see also : 'setState'</span>
<a name="line-122"></a>
<a name="line-123"></a><a name="setSysState"></a><span class='definition'>setSysState</span> <span class='keyglyph'>::</span> <span class='conid'>SysState</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>SysState</span>
<a name="line-124"></a><span class='definition'>setSysState</span> <span class='varid'>s</span>
<a name="line-125"></a> <span class='keyglyph'>=</span> <span class='varid'>changeSysState</span> <span class='layout'>(</span> <span class='keyglyph'>\</span><span class='keyword'>_</span> <span class='keyglyph'>-></span> <span class='varid'>s</span> <span class='layout'>)</span>
<a name="line-126"></a>
<a name="line-127"></a><span class='comment'>-- |</span>
<a name="line-128"></a><span class='comment'>-- read the system part of the state.</span>
<a name="line-129"></a><span class='comment'>--</span>
<a name="line-130"></a><span class='comment'>-- see also : 'getState'</span>
<a name="line-131"></a>
<a name="line-132"></a><a name="getSysState"></a><span class='definition'>getSysState</span> <span class='keyglyph'>::</span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>SysState</span>
<a name="line-133"></a><span class='definition'>getSysState</span>
<a name="line-134"></a> <span class='keyglyph'>=</span> <span class='varid'>changeSysState</span> <span class='varid'>id</span>
<a name="line-135"></a>
<a name="line-136"></a><span class='comment'>-- |</span>
<a name="line-137"></a><span class='comment'>-- the initial system state</span>
<a name="line-138"></a><span class='comment'>--</span>
<a name="line-139"></a><span class='comment'>-- an empty list of attribute value pairs</span>
<a name="line-140"></a>
<a name="line-141"></a><a name="initialSysState"></a><span class='definition'>initialSysState</span> <span class='keyglyph'>::</span> <span class='conid'>SysState</span>
<a name="line-142"></a><span class='definition'>initialSysState</span>
<a name="line-143"></a> <span class='keyglyph'>=</span> <span class='conid'>SysState</span> <span class='layout'>{</span> <span class='varid'>sysStateAttrs</span> <span class='keyglyph'>=</span> <span class='conid'>[]</span>
<a name="line-144"></a> <span class='layout'>,</span> <span class='varid'>sysStateErrorHandler</span> <span class='keyglyph'>=</span> <span class='varid'>errorMsgToStderr</span>
<a name="line-145"></a> <span class='layout'>}</span>
<a name="line-146"></a>
<a name="line-147"></a><span class='comment'>-- |</span>
<a name="line-148"></a><span class='comment'>-- change the attributes in the system state</span>
<a name="line-149"></a>
<a name="line-150"></a><a name="changeSysStateAttrs"></a><span class='definition'>changeSysStateAttrs</span> <span class='keyglyph'>::</span> <span class='layout'>(</span><span class='conid'>SysStateAttrs</span> <span class='keyglyph'>-></span> <span class='conid'>SysStateAttrs</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='layout'>(</span><span class='conid'>SysState</span> <span class='keyglyph'>-></span> <span class='conid'>SysState</span><span class='layout'>)</span>
<a name="line-151"></a><span class='definition'>changeSysStateAttrs</span> <span class='varid'>cf</span> <span class='varid'>sstate</span>
<a name="line-152"></a> <span class='keyglyph'>=</span> <span class='varid'>sstate</span> <span class='layout'>{</span> <span class='varid'>sysStateAttrs</span> <span class='keyglyph'>=</span> <span class='varid'>cf</span> <span class='layout'>(</span><span class='varid'>sysStateAttrs</span> <span class='varid'>sstate</span><span class='layout'>)</span> <span class='layout'>}</span>
<a name="line-153"></a>
<a name="line-154"></a>
<a name="line-155"></a><span class='comment'>-- |</span>
<a name="line-156"></a><span class='comment'>-- set the error message handler</span>
<a name="line-157"></a>
<a name="line-158"></a><a name="setSysErrorHandler"></a><span class='definition'>setSysErrorHandler</span> <span class='keyglyph'>::</span> <span class='conid'>XmlStateFilter</span> <span class='conid'>()</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>()</span>
<a name="line-159"></a><span class='definition'>setSysErrorHandler</span> <span class='varid'>ehf</span>
<a name="line-160"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-161"></a> <span class='varid'>changeSysState</span> <span class='layout'>(</span><span class='keyglyph'>\</span> <span class='varid'>s</span> <span class='keyglyph'>-></span> <span class='varid'>s</span> <span class='layout'>{</span> <span class='varid'>sysStateErrorHandler</span> <span class='keyglyph'>=</span> <span class='varid'>ehf</span> <span class='layout'>}</span><span class='layout'>)</span>
<a name="line-162"></a> <span class='varid'>return</span> <span class='conid'>()</span>
<a name="line-163"></a>
<a name="line-164"></a><span class='comment'>-- |</span>
<a name="line-165"></a><span class='comment'>-- get the error handler</span>
<a name="line-166"></a>
<a name="line-167"></a><a name="getSysErrorHandler"></a><span class='definition'>getSysErrorHandler</span> <span class='keyglyph'>::</span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='layout'>(</span><span class='conid'>XmlStateFilter</span> <span class='conid'>()</span><span class='layout'>)</span>
<a name="line-168"></a><span class='definition'>getSysErrorHandler</span>
<a name="line-169"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-170"></a> <span class='varid'>s</span> <span class='keyglyph'><-</span> <span class='varid'>getSysState</span>
<a name="line-171"></a> <span class='varid'>return</span> <span class='layout'>(</span><span class='varid'>sysStateErrorHandler</span> <span class='varid'>s</span><span class='layout'>)</span>
<a name="line-172"></a>
<a name="line-173"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-174"></a>
<a name="line-175"></a><span class='comment'>-- |</span>
<a name="line-176"></a><span class='comment'>-- set or change a single system parameter.</span>
<a name="line-177"></a><span class='comment'>--</span>
<a name="line-178"></a><span class='comment'>-- * 1.parameter name : the name of the parameter</span>
<a name="line-179"></a><span class='comment'>--</span>
<a name="line-180"></a><span class='comment'>-- - 2.parameter value : the list of associated trees</span>
<a name="line-181"></a><span class='comment'>--</span>
<a name="line-182"></a><span class='comment'>-- - returns : nothing</span>
<a name="line-183"></a><span class='comment'>--</span>
<a name="line-184"></a><span class='comment'>-- see also : 'setSysParam', 'setSysParamInt'</span>
<a name="line-185"></a>
<a name="line-186"></a><a name="setSysParamTree"></a><span class='definition'>setSysParamTree</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlTrees</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>()</span>
<a name="line-187"></a><span class='definition'>setSysParamTree</span> <span class='varid'>name</span> <span class='varid'>val</span>
<a name="line-188"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-189"></a> <span class='varid'>changeSysState</span> <span class='layout'>(</span><span class='varid'>changeSysStateAttrs</span> <span class='layout'>(</span><span class='varid'>addEntry</span> <span class='varid'>name</span> <span class='varid'>val</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-190"></a> <span class='varid'>return</span> <span class='conid'>()</span>
<a name="line-191"></a>
<a name="line-192"></a><span class='comment'>-- |</span>
<a name="line-193"></a><span class='comment'>-- set or change a single system parameter of type string.</span>
<a name="line-194"></a><span class='comment'>--</span>
<a name="line-195"></a><span class='comment'>-- * 1.parameter name : the name of the parameter</span>
<a name="line-196"></a><span class='comment'>--</span>
<a name="line-197"></a><span class='comment'>-- - 2.parameter value : the (new) string value</span>
<a name="line-198"></a><span class='comment'>--</span>
<a name="line-199"></a><span class='comment'>-- - returns : nothing</span>
<a name="line-200"></a><span class='comment'>--</span>
<a name="line-201"></a><span class='comment'>-- see also : 'setSysParamTree', setSysParamInt</span>
<a name="line-202"></a>
<a name="line-203"></a><a name="setSysParam"></a><span class='definition'>setSysParam</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>()</span>
<a name="line-204"></a><span class='definition'>setSysParam</span> <span class='varid'>name</span> <span class='varid'>val</span>
<a name="line-205"></a> <span class='keyglyph'>=</span> <span class='varid'>setSysParamTree</span> <span class='varid'>name</span> <span class='layout'>(</span><span class='varid'>xtext</span> <span class='varid'>val</span><span class='layout'>)</span>
<a name="line-206"></a>
<a name="line-207"></a><span class='comment'>-- |</span>
<a name="line-208"></a><span class='comment'>-- set or change a single integer type system parameter</span>
<a name="line-209"></a><span class='comment'>--</span>
<a name="line-210"></a><span class='comment'>-- see also : 'setSysParam'</span>
<a name="line-211"></a>
<a name="line-212"></a><a name="setSysParamInt"></a><span class='definition'>setSysParamInt</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>Int</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>()</span>
<a name="line-213"></a><span class='definition'>setSysParamInt</span> <span class='varid'>name</span> <span class='varid'>val</span> <span class='keyglyph'>=</span> <span class='varid'>setSysParam</span> <span class='varid'>name</span> <span class='layout'>(</span><span class='varid'>show</span> <span class='varid'>val</span><span class='layout'>)</span>
<a name="line-214"></a>
<a name="line-215"></a><span class='comment'>-- |</span>
<a name="line-216"></a><span class='comment'>-- add (or change) all attributes of the document root to the system state</span>
<a name="line-217"></a><span class='comment'>-- - returns : this</span>
<a name="line-218"></a>
<a name="line-219"></a><a name="setSystemParams"></a><span class='definition'>setSystemParams</span> <span class='keyglyph'>::</span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-220"></a><span class='definition'>setSystemParams</span> <span class='varid'>t</span>
<a name="line-221"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-222"></a> <span class='varid'>changeSysState</span> <span class='layout'>(</span><span class='varid'>changeSysStateAttrs</span> <span class='layout'>(</span><span class='varid'>addEntries</span> <span class='layout'>(</span><span class='varid'>toTreel</span> <span class='varop'>.</span> <span class='varid'>getAttrl</span> <span class='varop'>$</span> <span class='varid'>t</span><span class='layout'>)</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-223"></a> <span class='varid'>thisM</span> <span class='varid'>t</span>
<a name="line-224"></a>
<a name="line-225"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-226"></a>
<a name="line-227"></a><span class='comment'>-- |</span>
<a name="line-228"></a><span class='comment'>-- read a system parameter</span>
<a name="line-229"></a><span class='comment'>--</span>
<a name="line-230"></a><span class='comment'>-- * 1.parameter name : the name of the parameter</span>
<a name="line-231"></a><span class='comment'>--</span>
<a name="line-232"></a><span class='comment'>-- - returns : the list of tres associated with the key, or the empty list for unknown parameters</span>
<a name="line-233"></a>
<a name="line-234"></a><a name="getSysParamTree"></a><span class='definition'>getSysParamTree</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>XmlTrees</span>
<a name="line-235"></a><span class='definition'>getSysParamTree</span> <span class='varid'>name</span>
<a name="line-236"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-237"></a> <span class='varid'>s</span> <span class='keyglyph'><-</span> <span class='varid'>getSysState</span>
<a name="line-238"></a> <span class='varid'>return</span> <span class='layout'>(</span><span class='varid'>lookup1</span> <span class='varid'>name</span> <span class='layout'>(</span><span class='varid'>sysStateAttrs</span> <span class='varid'>s</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-239"></a>
<a name="line-240"></a><span class='comment'>-- |</span>
<a name="line-241"></a><span class='comment'>-- read a system string parameter</span>
<a name="line-242"></a><span class='comment'>--</span>
<a name="line-243"></a><span class='comment'>-- * 1.parameter name : the name of the parameter</span>
<a name="line-244"></a><span class='comment'>--</span>
<a name="line-245"></a><span class='comment'>-- - returns : the value, or the empty string for unknown parameters</span>
<a name="line-246"></a>
<a name="line-247"></a><a name="getSysParam"></a><span class='definition'>getSysParam</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>String</span>
<a name="line-248"></a><span class='definition'>getSysParam</span> <span class='varid'>name</span>
<a name="line-249"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-250"></a> <span class='varid'>ts</span> <span class='keyglyph'><-</span> <span class='varid'>getSysParamTree</span> <span class='varid'>name</span>
<a name="line-251"></a> <span class='varid'>return</span> <span class='layout'>(</span><span class='varid'>xshow</span> <span class='varid'>ts</span><span class='layout'>)</span>
<a name="line-252"></a>
<a name="line-253"></a><span class='comment'>-- |</span>
<a name="line-254"></a><span class='comment'>-- read a system parameter or return a default value</span>
<a name="line-255"></a><span class='comment'>--</span>
<a name="line-256"></a><span class='comment'>-- * 1.parameter name : the name of the parameter</span>
<a name="line-257"></a><span class='comment'>--</span>
<a name="line-258"></a><span class='comment'>-- - 2.parameter default : the default value</span>
<a name="line-259"></a><span class='comment'>--</span>
<a name="line-260"></a><span class='comment'>-- - returns : the value if found, else the default</span>
<a name="line-261"></a>
<a name="line-262"></a><a name="getSysParamWithDefault"></a><span class='definition'>getSysParamWithDefault</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>String</span>
<a name="line-263"></a><span class='definition'>getSysParamWithDefault</span> <span class='varid'>name</span> <span class='varid'>def</span>
<a name="line-264"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-265"></a> <span class='varid'>val</span> <span class='keyglyph'><-</span> <span class='varid'>getSysParam</span> <span class='varid'>name</span>
<a name="line-266"></a> <span class='varid'>return</span> <span class='layout'>(</span> <span class='keyword'>if</span> <span class='varid'>null</span> <span class='varid'>val</span>
<a name="line-267"></a> <span class='keyword'>then</span> <span class='varid'>def</span>
<a name="line-268"></a> <span class='keyword'>else</span> <span class='varid'>val</span>
<a name="line-269"></a> <span class='layout'>)</span>
<a name="line-270"></a>
<a name="line-271"></a><span class='comment'>-- |</span>
<a name="line-272"></a><span class='comment'>-- read an integer system parameter</span>
<a name="line-273"></a><span class='comment'>--</span>
<a name="line-274"></a><span class='comment'>-- * 1.parameter name : </span>
<a name="line-275"></a><span class='comment'>--</span>
<a name="line-276"></a><span class='comment'>-- - 2.parameter default : </span>
<a name="line-277"></a><span class='comment'>--</span>
<a name="line-278"></a><span class='comment'>-- see also : 'getSysParamWithDefault'</span>
<a name="line-279"></a>
<a name="line-280"></a><a name="getSysParamInt"></a><span class='definition'>getSysParamInt</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>Int</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>Int</span>
<a name="line-281"></a><span class='definition'>getSysParamInt</span> <span class='varid'>var</span> <span class='varid'>def</span>
<a name="line-282"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-283"></a> <span class='varid'>val</span> <span class='keyglyph'><-</span> <span class='varid'>getSysParamWithDefault</span> <span class='varid'>var</span> <span class='layout'>(</span><span class='varid'>show</span> <span class='varid'>def</span><span class='layout'>)</span>
<a name="line-284"></a> <span class='varid'>return</span> <span class='layout'>(</span><span class='varid'>read</span> <span class='varid'>val</span><span class='layout'>)</span>
<a name="line-285"></a>
<a name="line-286"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-287"></a>
<a name="line-288"></a><span class='comment'>-- |</span>
<a name="line-289"></a><span class='comment'>-- exec a XState command with initial state.</span>
<a name="line-290"></a><span class='comment'>--</span>
<a name="line-291"></a><span class='comment'>-- * 1.parameter initalState : the inital user state</span>
<a name="line-292"></a><span class='comment'>--</span>
<a name="line-293"></a><span class='comment'>-- - 2.parameter cmd : the command</span>
<a name="line-294"></a><span class='comment'>--</span>
<a name="line-295"></a><span class='comment'>-- - returns : the i\/o command with result and user state</span>
<a name="line-296"></a>
<a name="line-297"></a><a name="run0"></a><span class='definition'>run0</span> <span class='keyglyph'>::</span> <span class='conid'>XmlState</span> <span class='varid'>state</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='varid'>res</span> <span class='keyglyph'>-></span> <span class='conid'>IO</span> <span class='layout'>(</span><span class='varid'>res</span><span class='layout'>,</span> <span class='conid'>XmlState</span> <span class='varid'>state</span><span class='layout'>)</span>
<a name="line-298"></a><span class='definition'>run0</span> <span class='varid'>initialState</span> <span class='layout'>(</span><span class='conid'>MonadStateIO</span><span class='varop'>.</span><span class='conid'>STIO</span> <span class='varid'>cmd</span><span class='layout'>)</span>
<a name="line-299"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-300"></a> <span class='layout'>(</span><span class='varid'>res</span><span class='layout'>,</span> <span class='varid'>finalState</span><span class='layout'>)</span> <span class='keyglyph'><-</span> <span class='varid'>cmd</span> <span class='varid'>initialState</span>
<a name="line-301"></a> <span class='varid'>return</span> <span class='layout'>(</span><span class='varid'>res</span><span class='layout'>,</span> <span class='varid'>finalState</span><span class='layout'>)</span>
<a name="line-302"></a>
<a name="line-303"></a><span class='comment'>-- |</span>
<a name="line-304"></a><span class='comment'>-- exec a XState command with initial user state.</span>
<a name="line-305"></a><span class='comment'>-- ignore final user state.</span>
<a name="line-306"></a><span class='comment'>-- like run0, but ignore the resulting user state</span>
<a name="line-307"></a>
<a name="line-308"></a><a name="run"></a><span class='definition'>run</span> <span class='keyglyph'>::</span> <span class='varid'>state</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='varid'>res</span> <span class='keyglyph'>-></span> <span class='conid'>IO</span> <span class='varid'>res</span>
<a name="line-309"></a><span class='definition'>run</span> <span class='varid'>initialUserState</span> <span class='varid'>cmd</span>
<a name="line-310"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-311"></a> <span class='layout'>(</span><span class='varid'>res</span><span class='layout'>,</span> <span class='sel'>_finalState</span><span class='layout'>)</span> <span class='keyglyph'><-</span> <span class='varid'>run0</span> <span class='layout'>(</span><span class='conid'>XmlState</span> <span class='varid'>initialSysState</span> <span class='varid'>initialUserState</span><span class='layout'>)</span> <span class='varid'>cmd</span>
<a name="line-312"></a> <span class='varid'>return</span> <span class='varid'>res</span>
<a name="line-313"></a>
<a name="line-314"></a><span class='comment'>-- |</span>
<a name="line-315"></a><span class='comment'>-- exec a XState command in th IO monad.</span>
<a name="line-316"></a><span class='comment'>-- like run with the empty state ().</span>
<a name="line-317"></a>
<a name="line-318"></a><a name="run'"></a><span class='definition'>run'</span> <span class='keyglyph'>::</span> <span class='conid'>XState</span> <span class='conid'>()</span> <span class='varid'>res</span> <span class='keyglyph'>-></span> <span class='conid'>IO</span> <span class='varid'>res</span>
<a name="line-319"></a><span class='definition'>run'</span> <span class='keyglyph'>=</span> <span class='varid'>run</span> <span class='conid'>()</span>
<a name="line-320"></a>
<a name="line-321"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-322"></a>
<a name="line-323"></a><span class='comment'>-- |</span>
<a name="line-324"></a><span class='comment'>-- run a command in a new user state.</span>
<a name="line-325"></a><span class='comment'>-- chain the system state part,</span>
<a name="line-326"></a><span class='comment'>-- init new system state with the current one, run the command and</span>
<a name="line-327"></a><span class='comment'>-- update the old system state with the resulting new system state</span>
<a name="line-328"></a><span class='comment'>--</span>
<a name="line-329"></a><span class='comment'>-- * 1.parameter initialUserState : the initial user state</span>
<a name="line-330"></a><span class='comment'>--</span>
<a name="line-331"></a><span class='comment'>-- - 2.parameter cmd : the command</span>
<a name="line-332"></a><span class='comment'>--</span>
<a name="line-333"></a><span class='comment'>-- - returns : the result of executing cmd and the final state</span>
<a name="line-334"></a>
<a name="line-335"></a><a name="chain'"></a><span class='definition'>chain'</span> <span class='keyglyph'>::</span> <span class='varid'>state1</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state1</span> <span class='varid'>res</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state0</span> <span class='layout'>(</span><span class='varid'>res</span><span class='layout'>,</span> <span class='varid'>state1</span><span class='layout'>)</span>
<a name="line-336"></a><span class='definition'>chain'</span> <span class='varid'>initialUserState1</span> <span class='varid'>cmd1</span>
<a name="line-337"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-338"></a> <span class='varid'>sysState0</span> <span class='keyglyph'><-</span> <span class='varid'>getSysState</span>
<a name="line-339"></a> <span class='layout'>(</span><span class='varid'>res</span><span class='layout'>,</span> <span class='varid'>finalState1</span><span class='layout'>)</span> <span class='keyglyph'><-</span> <span class='varid'>io</span> <span class='varop'>$</span> <span class='varid'>run0</span> <span class='layout'>(</span><span class='conid'>XmlState</span> <span class='varid'>sysState0</span> <span class='varid'>initialUserState1</span><span class='layout'>)</span> <span class='varid'>cmd1</span>
<a name="line-340"></a> <span class='varid'>setSysState</span> <span class='layout'>(</span><span class='varid'>sysState</span> <span class='varid'>finalState1</span><span class='layout'>)</span>
<a name="line-341"></a> <span class='varid'>return</span> <span class='layout'>(</span><span class='varid'>res</span><span class='layout'>,</span> <span class='layout'>(</span><span class='varid'>userState</span> <span class='varid'>finalState1</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-342"></a>
<a name="line-343"></a><span class='comment'>-- |</span>
<a name="line-344"></a><span class='comment'>-- like chain' but forget the final user state</span>
<a name="line-345"></a><span class='comment'>--</span>
<a name="line-346"></a><span class='comment'>-- * 1.parameter initialUserState : the initial user state</span>
<a name="line-347"></a><span class='comment'>--</span>
<a name="line-348"></a><span class='comment'>-- - 2.parameter cmd : the command</span>
<a name="line-349"></a><span class='comment'>--</span>
<a name="line-350"></a><span class='comment'>-- - returns : only the result of executing cmd</span>
<a name="line-351"></a>
<a name="line-352"></a><a name="chain"></a><span class='definition'>chain</span> <span class='keyglyph'>::</span> <span class='varid'>state1</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state1</span> <span class='varid'>res</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state0</span> <span class='varid'>res</span>
<a name="line-353"></a><span class='definition'>chain</span> <span class='varid'>initialUserState1</span> <span class='varid'>cmd1</span>
<a name="line-354"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-355"></a> <span class='layout'>(</span><span class='varid'>res</span><span class='layout'>,</span> <span class='keyword'>_</span><span class='layout'>)</span> <span class='keyglyph'><-</span> <span class='varid'>chain'</span> <span class='varid'>initialUserState1</span> <span class='varid'>cmd1</span>
<a name="line-356"></a> <span class='varid'>return</span> <span class='varid'>res</span>
<a name="line-357"></a>
<a name="line-358"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-359"></a><span class='comment'>--</span>
<a name="line-360"></a><span class='comment'>-- lift functions</span>
<a name="line-361"></a>
<a name="line-362"></a><span class='comment'>-- |</span>
<a name="line-363"></a><span class='comment'>-- lift a XmlFilter to a XmlStateFilter filter</span>
<a name="line-364"></a><span class='comment'>-- issue all error nodes as error messages</span>
<a name="line-365"></a><span class='comment'>-- and remove the error nodes from the result</span>
<a name="line-366"></a><span class='comment'>--</span>
<a name="line-367"></a><span class='comment'>-- * 1.parameter f : the filter</span>
<a name="line-368"></a><span class='comment'>--</span>
<a name="line-369"></a><span class='comment'>-- - returns : the filter running in the state monad</span>
<a name="line-370"></a><span class='comment'>--</span>
<a name="line-371"></a><span class='comment'>-- all errors are filtered from the result and issued on stderr</span>
<a name="line-372"></a>
<a name="line-373"></a><a name="liftF"></a><span class='definition'>liftF</span> <span class='keyglyph'>::</span> <span class='conid'>XmlFilter</span> <span class='keyglyph'>-></span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-374"></a><span class='definition'>liftF</span> <span class='varid'>f</span> <span class='keyglyph'>=</span> <span class='varid'>liftMf</span> <span class='varid'>f</span> <span class='varop'>.>></span> <span class='varid'>issueError</span>
<a name="line-375"></a>
<a name="line-376"></a><span class='comment'>-- |</span>
<a name="line-377"></a><span class='comment'>-- lift an I\/O command</span>
<a name="line-378"></a><span class='comment'>--</span>
<a name="line-379"></a><span class='comment'>-- * 1.parameter cmd : the i\/o command</span>
<a name="line-380"></a><span class='comment'>--</span>
<a name="line-381"></a><span class='comment'>-- - returns : the i\/o command lifted to the XML state monad</span>
<a name="line-382"></a>
<a name="line-383"></a><a name="io"></a><span class='definition'>io</span> <span class='keyglyph'>::</span> <span class='conid'>IO</span> <span class='varid'>a</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='varid'>a</span>
<a name="line-384"></a><span class='definition'>io</span> <span class='keyglyph'>=</span> <span class='conid'>MonadStateIO</span><span class='varop'>.</span><span class='varid'>io</span>
<a name="line-385"></a>
<a name="line-386"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-387"></a><span class='comment'>--</span>
<a name="line-388"></a>
<a name="line-389"></a><span class='comment'>-- |</span>
<a name="line-390"></a><span class='comment'>-- set the trace level.</span>
<a name="line-391"></a><span class='comment'>--</span>
<a name="line-392"></a><span class='comment'>-- convention:</span>
<a name="line-393"></a><span class='comment'>--</span>
<a name="line-394"></a><span class='comment'>-- 0: no trace output (default)</span>
<a name="line-395"></a><span class='comment'>--</span>
<a name="line-396"></a><span class='comment'>-- 1: trace important computation steps, e.g. accessing a document</span>
<a name="line-397"></a><span class='comment'>--</span>
<a name="line-398"></a><span class='comment'>-- 2: trace small computation steps</span>
<a name="line-399"></a><span class='comment'>--</span>
<a name="line-400"></a><span class='comment'>-- 3: output an intermediate result XmlTree in XML source format</span>
<a name="line-401"></a><span class='comment'>--</span>
<a name="line-402"></a><span class='comment'>-- 4: output an intermediate result XmlTree in tree representation</span>
<a name="line-403"></a><span class='comment'>--</span>
<a name="line-404"></a><span class='comment'>-- * 1.parameter level : the trace level</span>
<a name="line-405"></a><span class='comment'>--</span>
<a name="line-406"></a><span class='comment'>-- - returns : nothing</span>
<a name="line-407"></a>
<a name="line-408"></a><a name="setTraceLevel"></a><span class='definition'>setTraceLevel</span> <span class='keyglyph'>::</span> <span class='conid'>Int</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>()</span>
<a name="line-409"></a><span class='definition'>setTraceLevel</span> <span class='varid'>l</span> <span class='keyglyph'>=</span> <span class='varid'>setSysParamInt</span> <span class='varid'>a_trace</span> <span class='varid'>l</span>
<a name="line-410"></a>
<a name="line-411"></a><span class='comment'>-- |</span>
<a name="line-412"></a><span class='comment'>-- get the current trace level.</span>
<a name="line-413"></a><span class='comment'>--</span>
<a name="line-414"></a><span class='comment'>-- - returns : the current trace level</span>
<a name="line-415"></a>
<a name="line-416"></a><a name="getTraceLevel"></a><span class='definition'>getTraceLevel</span> <span class='keyglyph'>::</span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>Int</span>
<a name="line-417"></a><span class='definition'>getTraceLevel</span> <span class='keyglyph'>=</span> <span class='varid'>getSysParamInt</span> <span class='varid'>a_trace</span> <span class='num'>0</span>
<a name="line-418"></a>
<a name="line-419"></a><span class='comment'>-- |</span>
<a name="line-420"></a><span class='comment'>-- trace output for arbitray commands.</span>
<a name="line-421"></a><span class='comment'>--</span>
<a name="line-422"></a><span class='comment'>-- * 1.parameter level : the trace level,</span>
<a name="line-423"></a><span class='comment'>-- for which the command will be execuded</span>
<a name="line-424"></a><span class='comment'>-- if level \<= current trace level</span>
<a name="line-425"></a><span class='comment'>--</span>
<a name="line-426"></a><span class='comment'>-- - 2.parameter cmd : the command to be executed</span>
<a name="line-427"></a><span class='comment'>--</span>
<a name="line-428"></a><span class='comment'>-- - returns : nothing</span>
<a name="line-429"></a>
<a name="line-430"></a><a name="traceCmd"></a><span class='definition'>traceCmd</span> <span class='keyglyph'>::</span> <span class='conid'>Int</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='varid'>a</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>()</span>
<a name="line-431"></a><span class='definition'>traceCmd</span> <span class='varid'>level</span> <span class='varid'>cmd</span>
<a name="line-432"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-433"></a> <span class='varid'>trcLevel</span> <span class='keyglyph'><-</span> <span class='varid'>getTraceLevel</span>
<a name="line-434"></a> <span class='keyword'>if</span> <span class='varid'>level</span> <span class='varop'><=</span> <span class='varid'>trcLevel</span>
<a name="line-435"></a> <span class='keyword'>then</span> <span class='keyword'>do</span>
<a name="line-436"></a> <span class='keyword'>_</span> <span class='keyglyph'><-</span> <span class='varid'>cmd</span>
<a name="line-437"></a> <span class='varid'>return</span> <span class='conid'>()</span>
<a name="line-438"></a> <span class='keyword'>else</span> <span class='varid'>return</span> <span class='conid'>()</span>
<a name="line-439"></a>
<a name="line-440"></a><span class='comment'>-- |</span>
<a name="line-441"></a><span class='comment'>-- trace output function for simple text.</span>
<a name="line-442"></a><span class='comment'>--</span>
<a name="line-443"></a><span class='comment'>-- * 1.parameter level : like in traceCmd</span>
<a name="line-444"></a><span class='comment'>--</span>
<a name="line-445"></a><span class='comment'>-- - 2.parameter str : the test</span>
<a name="line-446"></a><span class='comment'>--</span>
<a name="line-447"></a><span class='comment'>-- - returns : nothing</span>
<a name="line-448"></a>
<a name="line-449"></a><a name="trace"></a><span class='definition'>trace</span> <span class='keyglyph'>::</span> <span class='conid'>Int</span> <span class='keyglyph'>-></span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>()</span>
<a name="line-450"></a><span class='definition'>trace</span> <span class='varid'>level</span> <span class='varid'>str</span>
<a name="line-451"></a> <span class='keyglyph'>=</span> <span class='varid'>traceCmd</span> <span class='varid'>level</span>
<a name="line-452"></a> <span class='varop'>$</span> <span class='keyword'>do</span>
<a name="line-453"></a> <span class='varid'>io</span> <span class='varop'>$</span> <span class='varid'>hPutStrLn</span> <span class='varid'>stderr</span> <span class='layout'>(</span><span class='str'>"-- ("</span> <span class='varop'>++</span> <span class='varid'>show</span> <span class='varid'>level</span> <span class='varop'>++</span> <span class='str'>") "</span> <span class='varop'>++</span> <span class='varid'>str</span><span class='layout'>)</span>
<a name="line-454"></a>
<a name="line-455"></a><span class='comment'>-- |</span>
<a name="line-456"></a><span class='comment'>-- trace output of the user part of the program state.</span>
<a name="line-457"></a><span class='comment'>--</span>
<a name="line-458"></a><span class='comment'>-- * 1.parameter level : like in traceCmd</span>
<a name="line-459"></a><span class='comment'>--</span>
<a name="line-460"></a><span class='comment'>-- - 2.parameter showFct : the toString function</span>
<a name="line-461"></a><span class='comment'>--</span>
<a name="line-462"></a><span class='comment'>-- - returns : nothing</span>
<a name="line-463"></a>
<a name="line-464"></a><a name="traceState"></a><span class='definition'>traceState</span> <span class='keyglyph'>::</span> <span class='conid'>Int</span> <span class='keyglyph'>-></span> <span class='layout'>(</span><span class='varid'>state</span> <span class='keyglyph'>-></span> <span class='conid'>String</span><span class='layout'>)</span> <span class='keyglyph'>-></span> <span class='conid'>XState</span> <span class='varid'>state</span> <span class='conid'>()</span>
<a name="line-465"></a><span class='definition'>traceState</span> <span class='varid'>level</span> <span class='varid'>fct</span>
<a name="line-466"></a> <span class='keyglyph'>=</span> <span class='varid'>traceCmd</span> <span class='varid'>level</span>
<a name="line-467"></a> <span class='varop'>$</span> <span class='keyword'>do</span>
<a name="line-468"></a> <span class='varid'>s</span> <span class='keyglyph'><-</span> <span class='varid'>getState</span>
<a name="line-469"></a> <span class='varid'>io</span> <span class='varop'>$</span> <span class='varid'>hPutStrLn</span> <span class='varid'>stderr</span> <span class='layout'>(</span><span class='varid'>fct</span> <span class='varid'>s</span><span class='layout'>)</span>
<a name="line-470"></a>
<a name="line-471"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-472"></a><span class='comment'>--</span>
<a name="line-473"></a><span class='comment'>-- error functions</span>
<a name="line-474"></a>
<a name="line-475"></a><span class='comment'>-- |</span>
<a name="line-476"></a><span class='comment'>-- filter to reset the state attribute 'a_status'</span>
<a name="line-477"></a><span class='comment'>-- - returns : this</span>
<a name="line-478"></a>
<a name="line-479"></a><a name="clearStatus"></a><span class='definition'>clearStatus</span> <span class='keyglyph'>::</span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-480"></a><span class='definition'>clearStatus</span> <span class='varid'>t</span>
<a name="line-481"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-482"></a> <span class='varid'>setSysParamInt</span> <span class='varid'>a_status</span> <span class='varid'>c_ok</span>
<a name="line-483"></a> <span class='varid'>thisM</span> <span class='varid'>t</span>
<a name="line-484"></a>
<a name="line-485"></a><span class='comment'>-- |</span>
<a name="line-486"></a><span class='comment'>-- report an error message.</span>
<a name="line-487"></a><span class='comment'>--</span>
<a name="line-488"></a><span class='comment'>-- - returns : if the input tree n represents an error, @res = []@</span>
<a name="line-489"></a><span class='comment'>-- and the error is processed by the errror handler filter (default: error is issued on stderr)</span>
<a name="line-490"></a><span class='comment'>-- else @res = [n]@</span>
<a name="line-491"></a><span class='comment'>--</span>
<a name="line-492"></a><span class='comment'>-- see also : 'issueErr'</span>
<a name="line-493"></a>
<a name="line-494"></a><a name="issueError"></a><span class='definition'>issueError</span> <span class='keyglyph'>::</span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-495"></a><span class='definition'>issueError</span>
<a name="line-496"></a> <span class='keyglyph'>=</span> <span class='layout'>(</span><span class='varid'>setErrorMsgLevel</span> <span class='varop'>.>></span> <span class='varid'>errorMsgHandler</span> <span class='varop'>.>></span> <span class='varid'>noneM</span><span class='layout'>)</span>
<a name="line-497"></a> <span class='varop'>`whenM`</span>
<a name="line-498"></a> <span class='varid'>isXError</span>
<a name="line-499"></a>
<a name="line-500"></a><a name="errorMsgHandler"></a><span class='definition'>errorMsgHandler</span> <span class='keyglyph'>::</span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-501"></a><span class='definition'>errorMsgHandler</span>
<a name="line-502"></a> <span class='keyglyph'>=</span> <span class='varid'>performAction</span>
<a name="line-503"></a> <span class='layout'>(</span> <span class='keyglyph'>\</span> <span class='varid'>t</span> <span class='keyglyph'>-></span> <span class='varid'>chain'</span> <span class='conid'>()</span> <span class='layout'>(</span> <span class='keyword'>do</span>
<a name="line-504"></a> <span class='varid'>ehf</span> <span class='keyglyph'><-</span> <span class='varid'>getSysErrorHandler</span>
<a name="line-505"></a> <span class='varid'>ehf</span> <span class='varid'>t</span>
<a name="line-506"></a> <span class='varid'>return</span> <span class='conid'>()</span>
<a name="line-507"></a> <span class='layout'>)</span>
<a name="line-508"></a> <span class='layout'>)</span>
<a name="line-509"></a>
<a name="line-510"></a><span class='comment'>-- |</span>
<a name="line-511"></a><span class='comment'>-- set the error level in system state</span>
<a name="line-512"></a>
<a name="line-513"></a><a name="setErrorMsgLevel"></a><span class='definition'>setErrorMsgLevel</span> <span class='keyglyph'>::</span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-514"></a><span class='definition'>setErrorMsgLevel</span>
<a name="line-515"></a> <span class='keyglyph'>=</span> <span class='varid'>performAction</span>
<a name="line-516"></a> <span class='layout'>(</span> <span class='keyglyph'>\</span> <span class='layout'>(</span><span class='conid'>NTree</span> <span class='layout'>(</span><span class='conid'>XError</span> <span class='varid'>level</span> <span class='sel'>_str</span><span class='layout'>)</span> <span class='sel'>_cs</span><span class='layout'>)</span> <span class='keyglyph'>-></span>
<a name="line-517"></a> <span class='keyword'>do</span>
<a name="line-518"></a> <span class='varid'>errLevel</span> <span class='keyglyph'><-</span> <span class='varid'>getSysParamInt</span> <span class='varid'>a_status</span> <span class='num'>0</span>
<a name="line-519"></a> <span class='varid'>setSysParamInt</span> <span class='varid'>a_status</span> <span class='layout'>(</span><span class='varid'>max</span> <span class='varid'>errLevel</span> <span class='varid'>level</span><span class='layout'>)</span>
<a name="line-520"></a> <span class='layout'>)</span>
<a name="line-521"></a>
<a name="line-522"></a><span class='comment'>-- |</span>
<a name="line-523"></a><span class='comment'>-- default error handler for writing errors to stderr</span>
<a name="line-524"></a>
<a name="line-525"></a><a name="errorMsgToStderr"></a><span class='definition'>errorMsgToStderr</span> <span class='keyglyph'>::</span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-526"></a><span class='definition'>errorMsgToStderr</span>
<a name="line-527"></a> <span class='keyglyph'>=</span> <span class='varid'>performAction</span>
<a name="line-528"></a> <span class='layout'>(</span> <span class='keyglyph'>\</span> <span class='layout'>(</span><span class='conid'>NTree</span> <span class='layout'>(</span><span class='conid'>XError</span> <span class='varid'>level</span> <span class='varid'>str</span><span class='layout'>)</span> <span class='sel'>_cs</span><span class='layout'>)</span> <span class='keyglyph'>-></span>
<a name="line-529"></a> <span class='varid'>io</span> <span class='varop'>$</span> <span class='varid'>hPutStrLn</span> <span class='varid'>stderr</span> <span class='layout'>(</span><span class='str'>"\n"</span> <span class='varop'>++</span> <span class='varid'>errClass</span> <span class='varid'>level</span> <span class='varop'>++</span> <span class='str'>": "</span> <span class='varop'>++</span> <span class='varid'>str</span><span class='layout'>)</span>
<a name="line-530"></a> <span class='layout'>)</span>
<a name="line-531"></a>
<a name="line-532"></a><span class='comment'>-- |</span>
<a name="line-533"></a><span class='comment'>-- error message handler for collecting all error messages</span>
<a name="line-534"></a><span class='comment'>-- all messages are stored under attribute 'a_error_log'</span>
<a name="line-535"></a><span class='comment'>-- they can be read with @getSysParamTree a_error_log@ or by</span>
<a name="line-536"></a><span class='comment'>-- applying the filter 'getErrorMsg' to the root node</span>
<a name="line-537"></a>
<a name="line-538"></a><a name="errorMsgLogging"></a><span class='definition'>errorMsgLogging</span> <span class='keyglyph'>::</span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-539"></a><span class='definition'>errorMsgLogging</span>
<a name="line-540"></a> <span class='keyglyph'>=</span> <span class='varid'>performAction</span>
<a name="line-541"></a> <span class='layout'>(</span> <span class='keyglyph'>\</span> <span class='varid'>t</span> <span class='keyglyph'>-></span>
<a name="line-542"></a> <span class='keyword'>do</span>
<a name="line-543"></a> <span class='varid'>errLog</span> <span class='keyglyph'><-</span> <span class='varid'>getSysParamTree</span> <span class='varid'>a_error_log</span>
<a name="line-544"></a> <span class='varid'>setSysParamTree</span> <span class='varid'>a_error_log</span> <span class='layout'>(</span><span class='varid'>t</span> <span class='conop'>:</span> <span class='varid'>errLog</span><span class='layout'>)</span>
<a name="line-545"></a> <span class='layout'>)</span>
<a name="line-546"></a>
<a name="line-547"></a><a name="errorMsgLoggingAndToStderr"></a><span class='definition'>errorMsgLoggingAndToStderr</span> <span class='keyglyph'>::</span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-548"></a><span class='definition'>errorMsgLoggingAndToStderr</span> <span class='keyglyph'>=</span> <span class='varid'>errorMsgLogging</span><span class='varop'>.>></span> <span class='varid'>errorMsgToStderr</span>
<a name="line-549"></a>
<a name="line-550"></a><span class='comment'>-- |</span>
<a name="line-551"></a><span class='comment'>-- the filter for reading all collected error mesages</span>
<a name="line-552"></a><span class='comment'>--</span>
<a name="line-553"></a><span class='comment'>-- result is the list of error messages, the input tree is ignored</span>
<a name="line-554"></a>
<a name="line-555"></a><a name="getErrorMsg"></a><span class='definition'>getErrorMsg</span> <span class='keyglyph'>::</span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-556"></a><span class='definition'>getErrorMsg</span> <span class='sel'>_t</span>
<a name="line-557"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-558"></a> <span class='varid'>el</span> <span class='keyglyph'><-</span> <span class='varid'>getSysParamTree</span> <span class='varid'>a_error_log</span>
<a name="line-559"></a> <span class='varid'>setSysParamTree</span> <span class='varid'>a_error_log</span> <span class='conid'>[]</span>
<a name="line-560"></a> <span class='varid'>return</span> <span class='layout'>(</span><span class='varid'>reverse</span> <span class='varid'>el</span><span class='layout'>)</span>
<a name="line-561"></a>
<a name="line-562"></a><span class='comment'>-- |</span>
<a name="line-563"></a><span class='comment'>-- error level translation</span>
<a name="line-564"></a><span class='comment'>-- 'c_warn' (1) : warning,</span>
<a name="line-565"></a><span class='comment'>-- 'c_err' (2): error (e.g. parse error, validation error, ...),</span>
<a name="line-566"></a><span class='comment'>-- 'c_fatal' (3) : fatal error (document access error, internal error, ...)</span>
<a name="line-567"></a>
<a name="line-568"></a><a name="errClass"></a><span class='definition'>errClass</span> <span class='keyglyph'>::</span> <span class='conid'>Int</span> <span class='keyglyph'>-></span> <span class='conid'>String</span>
<a name="line-569"></a><span class='definition'>errClass</span> <span class='varid'>l</span>
<a name="line-570"></a> <span class='keyglyph'>=</span> <span class='varid'>fromMaybe</span> <span class='str'>"fatal error"</span> <span class='varop'>.</span> <span class='varid'>lookup</span> <span class='varid'>l</span> <span class='varop'>$</span> <span class='varid'>msgList</span>
<a name="line-571"></a> <span class='keyword'>where</span>
<a name="line-572"></a> <span class='varid'>msgList</span> <span class='keyglyph'>=</span> <span class='keyglyph'>[</span> <span class='layout'>(</span><span class='varid'>c_ok</span><span class='layout'>,</span> <span class='str'>"no error"</span><span class='layout'>)</span>
<a name="line-573"></a> <span class='layout'>,</span> <span class='layout'>(</span><span class='varid'>c_warn</span><span class='layout'>,</span> <span class='str'>"warning"</span><span class='layout'>)</span>
<a name="line-574"></a> <span class='layout'>,</span> <span class='layout'>(</span><span class='varid'>c_err</span><span class='layout'>,</span> <span class='str'>"error"</span><span class='layout'>)</span>
<a name="line-575"></a> <span class='layout'>,</span> <span class='layout'>(</span><span class='varid'>c_fatal</span><span class='layout'>,</span> <span class='str'>"fatal error"</span><span class='layout'>)</span>
<a name="line-576"></a> <span class='keyglyph'>]</span>
<a name="line-577"></a>
<a name="line-578"></a><span class='comment'>-- |</span>
<a name="line-579"></a><span class='comment'>-- short cut for issuing a warning</span>
<a name="line-580"></a><span class='comment'>--</span>
<a name="line-581"></a><span class='comment'>-- see also : 'issueError', 'issueErr'</span>
<a name="line-582"></a>
<a name="line-583"></a><a name="issueWarn"></a><span class='definition'>issueWarn</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-584"></a><span class='definition'>issueWarn</span> <span class='varid'>msg</span> <span class='keyglyph'>=</span> <span class='varid'>liftMf</span> <span class='layout'>(</span><span class='varid'>warn</span> <span class='varid'>msg</span><span class='layout'>)</span> <span class='varop'>.>></span> <span class='varid'>issueError</span>
<a name="line-585"></a>
<a name="line-586"></a><span class='comment'>-- |</span>
<a name="line-587"></a><span class='comment'>-- short cut for issuing an error</span>
<a name="line-588"></a><span class='comment'>--</span>
<a name="line-589"></a><span class='comment'>-- see also : 'issueError'</span>
<a name="line-590"></a>
<a name="line-591"></a><a name="issueErr"></a><span class='definition'>issueErr</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-592"></a><span class='definition'>issueErr</span> <span class='varid'>msg</span> <span class='keyglyph'>=</span> <span class='varid'>liftMf</span> <span class='layout'>(</span><span class='varid'>err</span> <span class='varid'>msg</span><span class='layout'>)</span> <span class='varop'>.>></span> <span class='varid'>issueError</span>
<a name="line-593"></a>
<a name="line-594"></a><span class='comment'>-- |</span>
<a name="line-595"></a><span class='comment'>-- short cut for issuing a fatal error</span>
<a name="line-596"></a><span class='comment'>--</span>
<a name="line-597"></a><span class='comment'>-- see also : 'issueError', 'issueErr'</span>
<a name="line-598"></a>
<a name="line-599"></a><a name="issueFatal"></a><span class='definition'>issueFatal</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-600"></a><span class='definition'>issueFatal</span> <span class='varid'>msg</span> <span class='keyglyph'>=</span> <span class='varid'>liftMf</span> <span class='layout'>(</span><span class='varid'>fatal</span> <span class='varid'>msg</span><span class='layout'>)</span> <span class='varop'>.>></span> <span class='varid'>issueError</span>
<a name="line-601"></a>
<a name="line-602"></a>
<a name="line-603"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-604"></a><span class='comment'>--</span>
<a name="line-605"></a><span class='comment'>-- issue an error, add the error to the document root tree</span>
<a name="line-606"></a><span class='comment'>-- and return the tree</span>
<a name="line-607"></a>
<a name="line-608"></a><a name="addFatal"></a><span class='definition'>addFatal</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-609"></a><span class='definition'>addFatal</span> <span class='varid'>msg</span>
<a name="line-610"></a> <span class='keyglyph'>=</span> <span class='varid'>liftF</span> <span class='layout'>(</span> <span class='varid'>fatal</span> <span class='varid'>msg</span>
<a name="line-611"></a> <span class='varop'>+++</span>
<a name="line-612"></a> <span class='varid'>setStatus</span> <span class='varid'>c_fatal</span> <span class='str'>"accessing documents"</span>
<a name="line-613"></a> <span class='layout'>)</span>
<a name="line-614"></a>
<a name="line-615"></a><span class='comment'>-- ------------------------------------------------------------</span>
<a name="line-616"></a>
<a name="line-617"></a><span class='comment'>-- |</span>
<a name="line-618"></a><span class='comment'>-- checks the value of the attribute 'a_status' in a document root.</span>
<a name="line-619"></a><span class='comment'>-- if it contains a value greater or equal to 'c_err', an error with error message</span>
<a name="line-620"></a><span class='comment'>-- stored in attribute 'a_module' is issued and the filter acts as the 'noneM' filter</span>
<a name="line-621"></a><span class='comment'>-- else its the 'thisM' filter</span>
<a name="line-622"></a>
<a name="line-623"></a><a name="checkStatus"></a><span class='definition'>checkStatus</span> <span class='keyglyph'>::</span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-624"></a><span class='definition'>checkStatus</span> <span class='varid'>t</span>
<a name="line-625"></a> <span class='keyglyph'>=</span> <span class='keyword'>if</span> <span class='varid'>status</span> <span class='varop'>>=</span> <span class='varid'>c_err</span>
<a name="line-626"></a> <span class='keyword'>then</span> <span class='keyword'>do</span>
<a name="line-627"></a> <span class='varid'>errorMsgHandler</span> <span class='layout'>(</span><span class='varid'>mkXErrorTree</span> <span class='varid'>c_warn</span> <span class='layout'>(</span><span class='varid'>errClass</span> <span class='varid'>status</span> <span class='varop'>++</span> <span class='str'>"s detected in "</span> <span class='varop'>++</span> <span class='varid'>msg</span><span class='layout'>)</span> <span class='conid'>[]</span><span class='layout'>)</span>
<a name="line-628"></a> <span class='varid'>noneM</span> <span class='varid'>t</span>
<a name="line-629"></a> <span class='keyword'>else</span>
<a name="line-630"></a> <span class='varid'>thisM</span> <span class='varid'>t</span>
<a name="line-631"></a> <span class='keyword'>where</span>
<a name="line-632"></a> <span class='varid'>status</span> <span class='keyglyph'>=</span> <span class='varid'>intValueOf</span> <span class='varid'>a_status</span> <span class='varid'>t</span>
<a name="line-633"></a> <span class='varid'>msg</span> <span class='keyglyph'>=</span> <span class='varid'>valueOf</span> <span class='varid'>a_module</span> <span class='varid'>t</span>
<a name="line-634"></a>
<a name="line-635"></a><span class='comment'>-- |</span>
<a name="line-636"></a><span class='comment'>-- add the error level and the module where the error occured</span>
<a name="line-637"></a><span class='comment'>-- to the attributes of a document root node and remove the children when level is greater or equal to 'c_err'</span>
<a name="line-638"></a>
<a name="line-639"></a><a name="setStatus"></a><span class='definition'>setStatus</span> <span class='keyglyph'>::</span> <span class='conid'>Int</span> <span class='keyglyph'>-></span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlFilter</span>
<a name="line-640"></a><span class='definition'>setStatus</span> <span class='varid'>level</span> <span class='varid'>msg</span>
<a name="line-641"></a> <span class='keyglyph'>=</span> <span class='layout'>(</span> <span class='varid'>addAttrInt</span> <span class='varid'>a_status</span> <span class='varid'>level</span>
<a name="line-642"></a> <span class='varop'>.></span>
<a name="line-643"></a> <span class='varid'>addAttr</span> <span class='varid'>a_module</span> <span class='varid'>msg</span>
<a name="line-644"></a> <span class='varop'>.></span>
<a name="line-645"></a> <span class='layout'>(</span> <span class='keyword'>if</span> <span class='varid'>level</span> <span class='varop'>>=</span> <span class='varid'>c_err</span>
<a name="line-646"></a> <span class='keyword'>then</span> <span class='varid'>replaceChildren</span> <span class='conid'>[]</span>
<a name="line-647"></a> <span class='keyword'>else</span> <span class='varid'>this</span>
<a name="line-648"></a> <span class='layout'>)</span>
<a name="line-649"></a> <span class='layout'>)</span>
<a name="line-650"></a> <span class='varop'>`when`</span> <span class='varid'>isRoot</span>
<a name="line-651"></a>
<a name="line-652"></a><span class='comment'>-- |</span>
<a name="line-653"></a><span class='comment'>-- check whether tree is a document root and the status attribute has a value less than 'c_err'</span>
<a name="line-654"></a>
<a name="line-655"></a><a name="statusOk"></a><span class='definition'>statusOk</span> <span class='keyglyph'>::</span> <span class='conid'>XmlFilter</span>
<a name="line-656"></a><span class='definition'>statusOk</span>
<a name="line-657"></a> <span class='keyglyph'>=</span> <span class='varid'>isRoot</span>
<a name="line-658"></a> <span class='varop'>.></span>
<a name="line-659"></a> <span class='varid'>isOf</span> <span class='layout'>(</span><span class='keyglyph'>\</span> <span class='varid'>t</span> <span class='keyglyph'>-></span> <span class='varid'>not</span> <span class='layout'>(</span><span class='varid'>intValueOf</span> <span class='varid'>a_status</span> <span class='varid'>t</span> <span class='varop'>>=</span> <span class='varid'>c_err</span><span class='layout'>)</span><span class='layout'>)</span>
<a name="line-660"></a><span class='comment'>-- |</span>
<a name="line-661"></a><span class='comment'>-- check whether the error level attribute in the system state</span>
<a name="line-662"></a><span class='comment'>-- is set to error, in this case the children of the document root are</span>
<a name="line-663"></a><span class='comment'>-- removed and error info is added as attributes with 'setStatus'</span>
<a name="line-664"></a><span class='comment'>-- else nothing is changed</span>
<a name="line-665"></a>
<a name="line-666"></a><a name="checkResult"></a><span class='definition'>checkResult</span> <span class='keyglyph'>::</span> <span class='conid'>String</span> <span class='keyglyph'>-></span> <span class='conid'>XmlStateFilter</span> <span class='varid'>state</span>
<a name="line-667"></a><span class='definition'>checkResult</span> <span class='varid'>msg</span> <span class='varid'>t</span>
<a name="line-668"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-669"></a> <span class='varid'>level</span> <span class='keyglyph'><-</span> <span class='varid'>getSysParamInt</span> <span class='varid'>a_status</span> <span class='num'>0</span>
<a name="line-670"></a> <span class='layout'>(</span> <span class='keyword'>if</span> <span class='varid'>level</span> <span class='varop'><=</span> <span class='varid'>c_warn</span>
<a name="line-671"></a> <span class='keyword'>then</span> <span class='varid'>thisM</span>
<a name="line-672"></a> <span class='keyword'>else</span> <span class='varid'>liftMf</span> <span class='layout'>(</span> <span class='varid'>setStatus</span> <span class='varid'>level</span> <span class='varid'>msg</span> <span class='layout'>)</span>
<a name="line-673"></a> <span class='layout'>)</span> <span class='varid'>t</span>
<a name="line-674"></a>
<a name="line-675"></a><span class='comment'>-- |</span>
<a name="line-676"></a><span class='comment'>-- monadic filter for processing the attribute list of a tag.</span>
<a name="line-677"></a><span class='comment'>-- for other trees this filter acts like 'noneM'</span>
<a name="line-678"></a><span class='comment'>--</span>
<a name="line-679"></a><span class='comment'>-- see also : 'processAttr', 'processAttrl'</span>
<a name="line-680"></a>
<a name="line-681"></a><a name="processAttrM"></a><span class='definition'>processAttrM</span> <span class='keyglyph'>::</span> <span class='conid'>XmlStateFilter</span> <span class='varid'>a</span> <span class='keyglyph'>-></span> <span class='conid'>XmlStateFilter</span> <span class='varid'>a</span>
<a name="line-682"></a><span class='definition'>processAttrM</span> <span class='varid'>f</span> <span class='varid'>t</span>
<a name="line-683"></a> <span class='keyglyph'>=</span> <span class='keyword'>do</span>
<a name="line-684"></a> <span class='varid'>res</span> <span class='keyglyph'><-</span> <span class='varid'>f</span> <span class='varop'>$$<</span> <span class='varid'>al</span>
<a name="line-685"></a> <span class='varid'>return</span> <span class='varop'>$</span> <span class='varid'>replaceAttrl</span> <span class='varid'>res</span> <span class='varid'>t</span>
<a name="line-686"></a> <span class='keyword'>where</span>
<a name="line-687"></a> <span class='varid'>al</span> <span class='keyglyph'>=</span> <span class='varid'>getAttrl</span> <span class='varid'>t</span>
<a name="line-688"></a>
<a name="line-689"></a><span class='comment'>-- ------------------------------------------------------------</span>
</pre></body>
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