Module log Log library provides logging facilities.
The module exposes extension points. It is possible to provide both the custom printing function and the custom log saving function.
The module is callable. Thus: 
local log = require"log"
log("MODULE", "INFO", "message")



 calls the #log.trace function.
			
			
Type levels

				

		

		levels.ALL
		7
		

		

		levels.DEBUG
		6
		

		

		levels.DETAIL
		5
		

		

		levels.ERROR
		2
		

		

		levels.INFO
		4
		

		

		levels.NONE
		1
		

		

		levels.WARNING
		3
		

	


			
			
Type log

				

		

		log.defaultlevel
		 Default verbosity level.
		

		

		log.displaylogger(severity, msg)
		 Default logger for instant display.
		

		

		log.format
		 Format is a string used to apply specific formating before the log is outputted.
		

		

		log.modules
		 Per module verbosity levels.
		

		

		log.musttrace(severity)
		 Determines whether a log must be traced depending on its severity and the module.
		

		

		log.setlevel(slevel, varargs)
		 Sets the log level for a list of module names.
		

		

		log.storelogger(severity, msg)
		 Logger function for log storage.
		

		

		log.trace(severity, fmt)
		 Prints out a log entry according to the module and the severity of the log entry.
		

	


			
Type levels

			
	
 Severity name <-> Severity numeric value translation table.

	
Built-in values (in order from the least verbose to the most):

	
Field(s)

		



		#number
levels.ALL



	7
	





		



		#number
levels.DEBUG



	6
	





		



		#number
levels.DETAIL



	5
	





		



		#number
levels.ERROR



	2
	





		



		#number
levels.INFO



	4
	





		



		#number
levels.NONE



	1
	





		



		#number
levels.WARNING



	3
	






			
Type log

			
	
Field(s)

		



		#levels
log.defaultlevel



	 Default verbosity level.
	
Default value is 'WARNING'.


		



log.displaylogger(severity, msg)



	 Default logger for instant display.
	
This logger can be replaced by a custom function. 

 It is called only if the log needs to be traced.
		
Parameters

		


		



		#string
log.format



	 Format is a string used to apply specific formating before the log is outputted.
	
Within a format, the following tokens are available (in addition to standard text)


		



log.modules



	 Per module verbosity levels.
	





		



log.musttrace(severity)



	 Determines whether a log must be traced depending on its severity and the module.
	
issuing the log.
		
Parameter

		
		
Return values

			
    
				
  1. 
				`nil' if the message of the given severity by the given module should
 not be printed.
				
    2. 
				
  2. 
				true if the message should be printed.
				
    3. 
			



		



log.setlevel(slevel, varargs)



	 Sets the log level for a list of module names.
	
If no module name is given, the default log level is affected
		
Parameters

		
		
Return value

			

				
				nothing.
			



		



log.storelogger(severity, msg)



	 Logger function for log storage.
	
This logger can be replaced by a custom function. 

 There is no default logger. 

 It is called only if the log needs to be traced (see #log.musttrace) and after the log has been displayed using {displaylogger}.
		
Parameters

		


		



log.trace(severity, fmt)



	 Prints out a log entry according to the module and the severity of the log entry.
	


 This function uses #log.format and #log.timestampformat to create the final message string. 

 It calls #log.displaylogger and #log.storelogger.
		
Parameters

		
	
Usage:

	
trace("MODULE", "INFO", "message=%s", "sometext").