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<pre><a name="line-1"></a><span class='hs-comment'>{- |
<a name="line-2"></a>
<a name="line-3"></a>Definition of log formatter support
<a name="line-4"></a>
<a name="line-5"></a>A few basic, and extendable formatters are defined.
<a name="line-6"></a>
<a name="line-7"></a>
<a name="line-8"></a>Please see "System.Log.Logger" for extensive documentation on the
<a name="line-9"></a>logging system.
<a name="line-10"></a>
<a name="line-11"></a>-}</span>
<a name="line-12"></a>
<a name="line-13"></a>
<a name="line-14"></a><span class='hs-keyword'>module</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Log</span><span class='hs-varop'>.</span><span class='hs-conid'>Formatter</span><span class='hs-layout'>(</span> <span class='hs-conid'>LogFormatter</span>
<a name="line-15"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>nullFormatter</span>
<a name="line-16"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>simpleLogFormatter</span>
<a name="line-17"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>tfLogFormatter</span>
<a name="line-18"></a> <span class='hs-layout'>,</span> <span class='hs-varid'>varFormatter</span>
<a name="line-19"></a> <span class='hs-layout'>)</span> <span class='hs-keyword'>where</span>
<a name="line-20"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>List</span>
<a name="line-21"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Applicative</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-varop'><$></span><span class='hs-layout'>)</span><span class='hs-layout'>)</span>
<a name="line-22"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Control</span><span class='hs-varop'>.</span><span class='hs-conid'>Concurrent</span> <span class='hs-layout'>(</span><span class='hs-varid'>myThreadId</span><span class='hs-layout'>)</span>
<a name="line-23"></a><span class='hs-cpp'>#ifndef mingw32_HOST_OS</span>
<a name="line-24"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Posix</span><span class='hs-varop'>.</span><span class='hs-conid'>Process</span> <span class='hs-layout'>(</span><span class='hs-varid'>getProcessID</span><span class='hs-layout'>)</span>
<a name="line-25"></a><span class='hs-cpp'>#endif</span>
<a name="line-26"></a>
<a name="line-27"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Locale</span> <span class='hs-layout'>(</span><span class='hs-varid'>defaultTimeLocale</span><span class='hs-layout'>)</span>
<a name="line-28"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>Data</span><span class='hs-varop'>.</span><span class='hs-conid'>Time</span> <span class='hs-layout'>(</span><span class='hs-varid'>getZonedTime</span><span class='hs-layout'>,</span><span class='hs-varid'>getCurrentTime</span><span class='hs-layout'>,</span><span class='hs-varid'>formatTime</span><span class='hs-layout'>)</span>
<a name="line-29"></a>
<a name="line-30"></a><span class='hs-keyword'>import</span> <span class='hs-conid'>System</span><span class='hs-varop'>.</span><span class='hs-conid'>Log</span>
<a name="line-31"></a>
<a name="line-32"></a><a name="LogFormatter"></a><span class='hs-comment'>-- | A LogFormatter is used to format log messages. Note that it is paramterized on the</span>
<a name="line-33"></a><a name="LogFormatter"></a><span class='hs-comment'>-- 'Handler' to allow the formatter to use information specific to the handler</span>
<a name="line-34"></a><a name="LogFormatter"></a><span class='hs-comment'>-- (an example of can be seen in the formatter used in 'System.Log.Handler.Syslog')</span>
<a name="line-35"></a><a name="LogFormatter"></a><span class='hs-keyword'>type</span> <span class='hs-conid'>LogFormatter</span> <span class='hs-varid'>a</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>a</span> <span class='hs-comment'>-- ^ The LogHandler that the passed message came from </span>
<a name="line-36"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>LogRecord</span> <span class='hs-comment'>-- ^ The log message and priority</span>
<a name="line-37"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span> <span class='hs-comment'>-- ^ The logger name</span>
<a name="line-38"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>String</span> <span class='hs-comment'>-- ^ The formatted log message</span>
<a name="line-39"></a>
<a name="line-40"></a><a name="nullFormatter"></a><span class='hs-comment'>-- | Returns the passed message as is, ie. no formatting is done.</span>
<a name="line-41"></a><span class='hs-definition'>nullFormatter</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>LogFormatter</span> <span class='hs-varid'>a</span>
<a name="line-42"></a><span class='hs-definition'>nullFormatter</span> <span class='hs-keyword'>_</span> <span class='hs-layout'>(</span><span class='hs-keyword'>_</span><span class='hs-layout'>,</span><span class='hs-varid'>msg</span><span class='hs-layout'>)</span> <span class='hs-keyword'>_</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-varid'>msg</span>
<a name="line-43"></a>
<a name="line-44"></a><a name="simpleLogFormatter"></a><span class='hs-comment'>-- | Takes a format string, and returns a formatter that may be used to</span>
<a name="line-45"></a><span class='hs-comment'>-- format log messages. The format string may contain variables prefixed with</span>
<a name="line-46"></a><span class='hs-comment'>-- a $-sign which will be replaced at runtime with corresponding values. The </span>
<a name="line-47"></a><span class='hs-comment'>-- currently supported variables are:</span>
<a name="line-48"></a><span class='hs-comment'>--</span>
<a name="line-49"></a><span class='hs-comment'>-- * @$msg@ - The actual log message</span>
<a name="line-50"></a><span class='hs-comment'>--</span>
<a name="line-51"></a><span class='hs-comment'>-- * @$loggername@ - The name of the logger</span>
<a name="line-52"></a><span class='hs-comment'>--</span>
<a name="line-53"></a><span class='hs-comment'>-- * @$prio@ - The priority level of the message</span>
<a name="line-54"></a><span class='hs-comment'>--</span>
<a name="line-55"></a><span class='hs-comment'>-- * @$tid@ - The thread ID</span>
<a name="line-56"></a><span class='hs-comment'>--</span>
<a name="line-57"></a><span class='hs-comment'>-- * @$pid@ - Process ID (Not available on windows)</span>
<a name="line-58"></a><span class='hs-comment'>--</span>
<a name="line-59"></a><span class='hs-comment'>-- * @$time@ - The current time </span>
<a name="line-60"></a><span class='hs-comment'>--</span>
<a name="line-61"></a><span class='hs-comment'>-- * @$utcTime@ - The current time in UTC Time</span>
<a name="line-62"></a><span class='hs-definition'>simpleLogFormatter</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>LogFormatter</span> <span class='hs-varid'>a</span>
<a name="line-63"></a><span class='hs-definition'>simpleLogFormatter</span> <span class='hs-varid'>format</span> <span class='hs-varid'>h</span> <span class='hs-layout'>(</span><span class='hs-varid'>prio</span><span class='hs-layout'>,</span> <span class='hs-varid'>msg</span><span class='hs-layout'>)</span> <span class='hs-varid'>loggername</span> <span class='hs-keyglyph'>=</span>
<a name="line-64"></a> <span class='hs-varid'>tfLogFormatter</span> <span class='hs-str'>"%F %X %Z"</span> <span class='hs-varid'>format</span> <span class='hs-varid'>h</span> <span class='hs-layout'>(</span><span class='hs-varid'>prio</span><span class='hs-layout'>,</span><span class='hs-varid'>msg</span><span class='hs-layout'>)</span> <span class='hs-varid'>loggername</span>
<a name="line-65"></a>
<a name="line-66"></a><a name="tfLogFormatter"></a><span class='hs-comment'>-- | Like 'simpleLogFormatter' but allow the time format to be specified in the first</span>
<a name="line-67"></a><span class='hs-comment'>-- parameter (this is passed to 'Date.Time.Format.formatTime')</span>
<a name="line-68"></a><span class='hs-definition'>tfLogFormatter</span> <span class='hs-keyglyph'>::</span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>LogFormatter</span> <span class='hs-varid'>a</span>
<a name="line-69"></a><span class='hs-definition'>tfLogFormatter</span> <span class='hs-varid'>timeFormat</span> <span class='hs-varid'>format</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-70"></a> <span class='hs-varid'>varFormatter</span> <span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-str'>"time"</span><span class='hs-layout'>,</span> <span class='hs-varid'>formatTime</span> <span class='hs-varid'>defaultTimeLocale</span> <span class='hs-varid'>timeFormat</span> <span class='hs-varop'><$></span> <span class='hs-varid'>getZonedTime</span><span class='hs-layout'>)</span>
<a name="line-71"></a> <span class='hs-layout'>,</span><span class='hs-layout'>(</span><span class='hs-str'>"utcTime"</span><span class='hs-layout'>,</span> <span class='hs-varid'>formatTime</span> <span class='hs-varid'>defaultTimeLocale</span> <span class='hs-varid'>timeFormat</span> <span class='hs-varop'><$></span> <span class='hs-varid'>getCurrentTime</span><span class='hs-layout'>)</span>
<a name="line-72"></a> <span class='hs-keyglyph'>]</span>
<a name="line-73"></a> <span class='hs-varid'>format</span>
<a name="line-74"></a>
<a name="line-75"></a><a name="varFormatter"></a><span class='hs-comment'>-- | An extensible formatter that allows new substition /variables/ to be defined.</span>
<a name="line-76"></a><span class='hs-comment'>-- Each variable has an associated IO action that is used to produce the</span>
<a name="line-77"></a><span class='hs-comment'>-- string to substitute for the variable name. The predefined variables are the same</span>
<a name="line-78"></a><span class='hs-comment'>-- as for 'simpleLogFormatter' /excluding/ @$time@ and @$utcTime@.</span>
<a name="line-79"></a><span class='hs-definition'>varFormatter</span> <span class='hs-keyglyph'>::</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'>IO</span> <span class='hs-conid'>String</span><span class='hs-layout'>)</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-conid'>LogFormatter</span> <span class='hs-varid'>a</span>
<a name="line-80"></a><span class='hs-definition'>varFormatter</span> <span class='hs-varid'>vars</span> <span class='hs-varid'>format</span> <span class='hs-varid'>h</span> <span class='hs-layout'>(</span><span class='hs-varid'>prio</span><span class='hs-layout'>,</span><span class='hs-varid'>msg</span><span class='hs-layout'>)</span> <span class='hs-varid'>loggername</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span>
<a name="line-81"></a> <span class='hs-varid'>outmsg</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>replaceVarM</span> <span class='hs-layout'>(</span><span class='hs-varid'>vars</span><span class='hs-varop'>++</span><span class='hs-keyglyph'>[</span><span class='hs-layout'>(</span><span class='hs-str'>"msg"</span><span class='hs-layout'>,</span> <span class='hs-varid'>return</span> <span class='hs-varid'>msg</span><span class='hs-layout'>)</span>
<a name="line-82"></a> <span class='hs-layout'>,</span><span class='hs-layout'>(</span><span class='hs-str'>"prio"</span><span class='hs-layout'>,</span> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-varid'>show</span> <span class='hs-varid'>prio</span><span class='hs-layout'>)</span>
<a name="line-83"></a> <span class='hs-layout'>,</span><span class='hs-layout'>(</span><span class='hs-str'>"loggername"</span><span class='hs-layout'>,</span> <span class='hs-varid'>return</span> <span class='hs-varid'>loggername</span><span class='hs-layout'>)</span>
<a name="line-84"></a> <span class='hs-layout'>,</span><span class='hs-layout'>(</span><span class='hs-str'>"tid"</span><span class='hs-layout'>,</span> <span class='hs-varid'>show</span> <span class='hs-varop'><$></span> <span class='hs-varid'>myThreadId</span><span class='hs-layout'>)</span>
<a name="line-85"></a><span class='hs-cpp'>#ifndef mingw32_HOST_OS</span>
<a name="line-86"></a> <span class='hs-layout'>,</span><span class='hs-layout'>(</span><span class='hs-str'>"pid"</span><span class='hs-layout'>,</span> <span class='hs-varid'>show</span> <span class='hs-varop'><$></span> <span class='hs-varid'>getProcessID</span><span class='hs-layout'>)</span>
<a name="line-87"></a><span class='hs-cpp'>#endif</span>
<a name="line-88"></a> <span class='hs-keyglyph'>]</span>
<a name="line-89"></a> <span class='hs-layout'>)</span>
<a name="line-90"></a> <span class='hs-varid'>format</span>
<a name="line-91"></a> <span class='hs-varid'>return</span> <span class='hs-varid'>outmsg</span>
<a name="line-92"></a>
<a name="line-93"></a>
<a name="line-94"></a><a name="replaceVarM"></a><span class='hs-comment'>-- | Replace some '$' variables in a string with supplied values</span>
<a name="line-95"></a><span class='hs-definition'>replaceVarM</span> <span class='hs-keyglyph'>::</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'>IO</span> <span class='hs-conid'>String</span><span class='hs-layout'>)</span><span class='hs-keyglyph'>]</span> <span class='hs-comment'>-- ^ A list of (variableName, action to get the replacement string) pairs</span>
<a name="line-96"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>String</span> <span class='hs-comment'>-- ^ String to perform substitution on</span>
<a name="line-97"></a> <span class='hs-keyglyph'>-></span> <span class='hs-conid'>IO</span> <span class='hs-conid'>String</span> <span class='hs-comment'>-- ^ Resulting string</span>
<a name="line-98"></a><span class='hs-definition'>replaceVarM</span> <span class='hs-keyword'>_</span> <span class='hs-conid'>[]</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-conid'>[]</span>
<a name="line-99"></a><span class='hs-definition'>replaceVarM</span> <span class='hs-varid'>keyVals</span> <span class='hs-layout'>(</span><span class='hs-varid'>s</span><span class='hs-conop'>:</span><span class='hs-varid'>ss</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>s</span><span class='hs-varop'>==</span><span class='hs-chr'>'$'</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-layout'>(</span><span class='hs-varid'>f</span><span class='hs-layout'>,</span><span class='hs-varid'>rest</span><span class='hs-layout'>)</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>replaceStart</span> <span class='hs-varid'>keyVals</span> <span class='hs-varid'>ss</span>
<a name="line-100"></a> <span class='hs-varid'>repRest</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>replaceVarM</span> <span class='hs-varid'>keyVals</span> <span class='hs-varid'>rest</span>
<a name="line-101"></a> <span class='hs-varid'>return</span> <span class='hs-varop'>$</span> <span class='hs-varid'>f</span> <span class='hs-varop'>++</span> <span class='hs-varid'>repRest</span>
<a name="line-102"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>replaceVarM</span> <span class='hs-varid'>keyVals</span> <span class='hs-varid'>ss</span> <span class='hs-varop'>>>=</span> <span class='hs-varid'>return</span> <span class='hs-varop'>.</span> <span class='hs-layout'>(</span><span class='hs-varid'>s</span><span class='hs-conop'>:</span><span class='hs-layout'>)</span>
<a name="line-103"></a> <span class='hs-keyword'>where</span>
<a name="line-104"></a> <span class='hs-varid'>replaceStart</span> <span class='hs-conid'>[]</span> <span class='hs-varid'>str</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-str'>"$"</span><span class='hs-layout'>,</span><span class='hs-varid'>str</span><span class='hs-layout'>)</span>
<a name="line-105"></a> <span class='hs-varid'>replaceStart</span> <span class='hs-layout'>(</span><span class='hs-layout'>(</span><span class='hs-varid'>k</span><span class='hs-layout'>,</span><span class='hs-varid'>v</span><span class='hs-layout'>)</span><span class='hs-conop'>:</span><span class='hs-varid'>kvs</span><span class='hs-layout'>)</span> <span class='hs-varid'>str</span> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>k</span> <span class='hs-varop'>`isPrefixOf`</span> <span class='hs-varid'>str</span> <span class='hs-keyglyph'>=</span> <span class='hs-keyword'>do</span> <span class='hs-varid'>vs</span> <span class='hs-keyglyph'><-</span> <span class='hs-varid'>v</span>
<a name="line-106"></a> <span class='hs-varid'>return</span> <span class='hs-layout'>(</span><span class='hs-varid'>vs</span><span class='hs-layout'>,</span> <span class='hs-varid'>drop</span> <span class='hs-layout'>(</span><span class='hs-varid'>length</span> <span class='hs-varid'>k</span><span class='hs-layout'>)</span> <span class='hs-varid'>str</span><span class='hs-layout'>)</span>
<a name="line-107"></a> <span class='hs-keyglyph'>|</span> <span class='hs-varid'>otherwise</span> <span class='hs-keyglyph'>=</span> <span class='hs-varid'>replaceStart</span> <span class='hs-varid'>kvs</span> <span class='hs-varid'>str</span>
<a name="line-108"></a>
<a name="line-109"></a>
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