Try - Revision history

Ximan: /* Usage Example */

2010-11-03T00:20:25Z

‎Usage Example

Ximan: /* See Also */

2010-11-03T00:19:49Z

‎See Also

Ximan: /* See Also */

2010-11-02T16:33:40Z

‎See Also

Ximan: /* See Also */

2010-11-02T16:33:17Z

‎See Also

Ximan: /* Calling Convention */

2010-11-02T16:09:53Z

‎Calling Convention

Ximan: /* Description */

2010-11-02T05:35:40Z

‎Description

Ximan: /* Description */

2010-11-02T05:34:14Z

‎Description

Ximan: /* Description */

2010-11-02T05:33:11Z

‎Description

Ximan: /* Description */

2010-11-02T05:32:38Z

‎Description

Ximan: Created page with "== Calling Convention == Call local r[,...] = sl.try(func,hndlr) Args func is a function hndlr is a function Results r1...rN results returned from func or r1...rN resul..."

2010-11-02T05:27:32Z

Created page with "== Calling Convention == Call local r[,...] = sl.try(func,hndlr) Args func is a function hndlr is a function Results r1...rN results returned from func or r1...rN resul..."

New page

== Calling Convention ==
Call
local r[,...] = sl.try(func,hndlr)
Args
func is a function
hndlr is a function
Results
r1...rN results returned from func
or
r1...rN results returned from hndlr, if func raises an error
or
r1...rN results returned from error handling callback, if set and enabled,
and hndlr reraises the error (see below)
or
ERR, eref if hndlr reraises error and inline handling enabled (see below)

== Usage Example ==

local sl = dofile(getinstalldir()..'/lib/simplelib.lua')
sl.slredirect('pi')
local f = function() local a = {} a = a + 1 + 'a' return a end
local h = function(err)
if type(err) == 'string' then
return 'error '..tostring(err)
else
local e = sl.geterror(err)
return e._errmsg
end
end
print(sl.try(f,h))

--> 'error ...\scripts\test00.lua:3: attempt to perform arithmetic on local 'a' (a table value)'

== Description ==

try is provided as a library wrapper for [[pcall]]. If the provided function func executes without generating any errors then its results are mirrored as the results of the try call. If an error is raised, then the function hndlr is called with a single argument, eref, a numeric reference to an error table that can be retrieved via [[geterror]]. If the handler raises an error (either an intentional reraising of the original, or a novel error), then further error handling is passed to the library and accomplished according to the reporting mode in effect: reraise (default), inlined, or using a library-wide user specified callback function. See [[http://www.easyuo.com/openeuo/wiki/index.php/Changing_Default_Error_Reporting_Mode error reporting modes]] for more information.

try is intended to be used to handle errors in user functions. In most instances, try should not be used directly on library calls, as they already have an internal form of try applied to them. Notable exceptions are the luo, macro, and str table methods.

== Upon Error ==

If try doesn't receive two valid functions as arguments, a library error is raised and handled according to the current redirection mode.

== See Also ==

* [[ERR]]

* [[error]]

* [[pcall]]

* [[nil]]

* [[null]]

* [[try]]

* [[type]]

* [http://www.easyuo.com/openeuo/wiki/index.php/Changing_Default_Error_Reporting_Mode error reporting modes]

← Older revision		Revision as of 00:19, 3 November 2010
Line 53:		Line 53:

	* [[error]]		* [[error]]
		+
		+	* [[geterror]]

	* [[pcall]]		* [[pcall]]

@@ Line 36: / Line 36: @@
 try is provided as a library wrapper for [[pcall]] which integrates library and script error handling. If the provided function func executes without generating any errors then its results are mirrored as the results of the try call.  If an error is raised within func, then the function hndlr is called with a single argument, err, either a numeric reference to an error table that can be retrieved via [[geterror]], or a string description of the error.
-If hndlr raises an error (either an intentional reraising using [[error]], or a novel error), then further error handling is passed to the library and accomplished according to the reporting mode in effect: reraise to system (default), inlined, or using a library-wide user specified callback function. The last two options are useful for designing scripts that fail gracefully (or, at least silently, lolz).  See [[http://www.easyuo.com/openeuo/wiki/index.php/Changing_Default_Error_Reporting_Mode error reporting modes]] for more information.
+If hndlr raises an error (either an intentional reraising using [[error]], or a novel error), then further error handling is passed to the library and accomplished according to the reporting mode in effect: reraise to system (default) resulting in the script halting, inlined and allowing execution to continue, or using a library-wide user specified callback function. The last two options are useful for designing scripts that fail gracefully (or, at least silently, lolz).  See [[http://www.easyuo.com/openeuo/wiki/index.php/Changing_Default_Error_Reporting_Mode error reporting modes]] for more information.
 try is intended to be used to handle errors in user functions that employ library methods.  In most instances, try should not be used directly on library calls, as they already have an internal form of try applied to them, and this will simply multiply the number of error messages recorded.  Notable exceptions are the [[luo]], [[macro]], and [[str]] table methods.

@@ Line 34: / Line 34: @@
 == Description ==
-try is provided as a library wrapper for [[pcall]]. If the provided function func executes without generating any errors then its results are mirrored as the results of the try call.  If an error is raised within func, then the function hndlr is called with a single argument, err, either a numeric reference to an error table that can be retrieved via [[geterror]], or a string description of the error.  If hndlr raises an error (either an intentional reraising using [[error]], or a novel error), then further error handling is passed to the library and accomplished according to the reporting mode in effect: reraise to system (default), inlined, or using a library-wide user specified callback function. The last two options are useful for designing scripts that fail gracefully (or, at least silently, lolz).  See [[http://www.easyuo.com/openeuo/wiki/index.php/Changing_Default_Error_Reporting_Mode error reporting modes]] for more information.
+try is provided as a library wrapper for [[pcall]] which integrates library and script error handling. If the provided function func executes without generating any errors then its results are mirrored as the results of the try call.  If an error is raised within func, then the function hndlr is called with a single argument, err, either a numeric reference to an error table that can be retrieved via [[geterror]], or a string description of the error.
 try is intended to be used to handle errors in user functions that employ library methods.  In most instances, try should not be used directly on library calls, as they already have an internal form of try applied to them, and this will simply multiply the number of error messages recorded.  Notable exceptions are the [[luo]], [[macro]], and [[str]] table methods.

@@ Line 36: / Line 36: @@
 try is provided as a library wrapper for [[pcall]]. If the provided function func executes without generating any errors then its results are mirrored as the results of the try call.  If an error is raised within func, then the function hndlr is called with a single argument, err, either a numeric reference to an error table that can be retrieved via [[geterror]], or a string description of the error.  If hndlr raises an error (either an intentional reraising using [[error]], or a novel error), then further error handling is passed to the library and accomplished according to the reporting mode in effect: reraise to system (default), inlined, or using a library-wide user specified callback function. The last two options are useful for designing scripts that fail gracefully (or, at least silently, lolz).  See [[http://www.easyuo.com/openeuo/wiki/index.php/Changing_Default_Error_Reporting_Mode error reporting modes]] for more information.
-try is intended to be used to handle errors in user functions that employ library methods.  In most instances, try should not be used directly on library calls, as they already have an internal form of try applied to them, and this will simply multiply the number of error messages recorded.  Notable exceptions are the luo, macro, and str table methods.
+try is intended to be used to handle errors in user functions that employ library methods.  In most instances, try should not be used directly on library calls, as they already have an internal form of try applied to them, and this will simply multiply the number of error messages recorded.  Notable exceptions are the [[luo]], [[macro]], and [[str]] table methods.
 == Upon Error ==

@@ Line 18: / Line 18: @@
   local sl = dofile(getinstalldir()..'/lib/simplelib.lua')
-  sl.slredirect('pi')
+  sl.slredirect('i')
   local f = function() local a  = {} a = a + 1 + 'a' return a end
   local h = function(err)

@@ Line 58: / Line 58: @@
 * [[nil]]
-* [[null]]
+* [[non]]
-* [[try]]
+* [[null]]
 * [[type]]

@@ Line 45: / Line 45: @@
 == See Also ==
 * [[ERR]]
@@ Line 59: / Line 63: @@
 * [[type]]

@@ Line 6: / Line 6: @@
   hndlr is a function
 Results
-  r1...rN   results returned from func
+  r0...rN    results returned from func
   or
-  r1...rN   results returned from hndlr, if func raises an error
+  r0...rN    results returned from hndlr, if func raises an error
   or
-  r1...rN   results returned from error handling callback, if set and enabled,
+  r0...rN    results returned from error handling callback, if set and enabled,
-           and hndlr reraises the error (see below)
+            and hndlr reraises the error (see below)
   or
-  ERR, eref if hndlr reraises error and inline handling enabled (see below)
+  ERR, eref  if hndlr reraises error and inline handling enabled (see below)
 == Usage Example ==