removed the DEH symbol ({%).

added new experimental features
 - the signal method to the Error class for simplified error/exception handling
 - the catch method to the BlockContext for simplified error/exception catching instead of the full-fledged on:do

moo/kernel/Apex.moo

@@ -354,4 +354,48 @@ extend Error
 	method(#primitive) asInteger.
 	method(#primitive) asCharacter.
 	method(#primitive) asString.
+
+	method signal
+	{
+		| exctx exblk retval actpos ctx |
+
+		exctx := (thisContext sender) findExceptionContext.
+
+		while (exctx notNil)
+		{
+			exblk := exctx findExceptionHandlerFor: (self class).
+			if (exblk notNil and: [actpos := exctx basicSize - 1. exctx basicAt: actpos])
+			{
+				exctx basicAt: actpos put: false.
+				[ retval := exblk value: self ] ensure: [ exctx basicAt: actpos put: true ].
+				thisContext unwindTo: (exctx sender) return: nil.
+				System return: retval to: (exctx sender).
+			}.
+			exctx := (exctx sender) findExceptionContext.
+		}.
+
+		## -----------------------------------------------------------------
+		## FATAL ERROR - no exception handler.
+		## -----------------------------------------------------------------
+		##thisContext unwindTo: nil return: nil.
+		##thisContext unwindTo: (Processor activeProcess initialContext) return: nil.
+		
+## TOOD: IMPROVE THIS EXPERIMENTAL BACKTRACE...
+System logNl: '== BACKTRACE =='.
+ctx := thisContext.
+while (ctx notNil)
+{
+	if (ctx class == MethodContext) { System logNl: (' ' & ctx method owner name & '>>' & ctx method name) }.
+	## TODO: include blockcontext???
+	ctx := ctx sender.
+}.
+System logNl: '== END OF BACKTRACE =='.
+
+		thisContext unwindTo: (thisProcess initialContext) return: nil.
+		('### ERROR NOT HANDLED #### ' & self class name & ' - ' & self asString) dump.
+		## TODO: debug the current process???? "
+
+		##Processor activeProcess terminate.
+		thisProcess terminate.
+	}
 }

moo/kernel/Context.moo

@@ -165,11 +165,11 @@ class(#pointer,#final,#limited) BlockContext(Context)
 		self primitiveFailed.
 	}
 
+
 	method ifTrue: aBlock
 	{
 		##^(self value) ifTrue: aBlock.
 		^if (self value) { aBlock value }.
-		
 	}
 
 	method ifFalse: aBlock

moo/kernel/Except.moo

@@ -6,7 +6,8 @@
 ##
 class Exception(Apex)
 {
-	var signalContext, handlerContext, messageText.
+	var signalContext, handlerContext.
+	var(#get) messageText.
 
 (*
 TODO: can i convert 'thisProcess primError' to a relevant exception?
@@ -18,7 +19,6 @@ TODO: can i convert 'thisProcess primError' to a relevant exception?
 	}
 *)
 
-
 	method(#class) signal
 	{
 		^self new signal
@@ -34,23 +34,12 @@ TODO: can i convert 'thisProcess primError' to a relevant exception?
 		self.handlerContext := context.
 	}
 
-	method messageText
-	{
-		^self.messageText
-	}
 
 	method asString
 	{
 		^(self class name) & ' - ' & self.messageText.
 	}
 
-	(* TODO: remove this....
-	method __signal 
-	{
-		self.signalContext := thisContext.
-		((thisContext sender) findExceptionContext) handleException: self.
-	}*)
-
 	method signal
 	{
 		| exctx exblk retval actpos ctx |
@@ -62,8 +51,7 @@ TODO: can i convert 'thisProcess primError' to a relevant exception?
 		while (exctx notNil)
 		{
 			exblk := exctx findExceptionHandlerFor: (self class).
-			if (exblk notNil and: 
-			    [actpos := exctx basicSize - 1. exctx basicAt: actpos])
+			if (exblk notNil and: [actpos := exctx basicSize - 1. exctx basicAt: actpos])
 			{
 				self.handlerContext := exctx.
 				exctx basicAt: actpos put: false.
@@ -180,7 +168,8 @@ extend Context
 	{
 		## -------------------------------------------------------------------
 		## <<private>>
-		## private: called by VM upon unwinding
+		## private: called by VM upon unwinding as well as by 
+		##          Exception<<signal and Error<<signal
 		## -------------------------------------------------------------------
 
 		| ctx stop eb pending_pos |
@@ -277,7 +266,9 @@ extend MethodContext
 			##	exc := self basicAt: i.
 			##	if ((exception_class == exc) or: [exception_class inheritsFrom: exc]) { ^self basicAt: (i + 1) }.
 			##]
-			i := MethodContext.Index.FIRST_ON.
+			
+			## start scanning from the position of the first parameter
+			i := MethodContext.Index.FIRST_ON. 
 			while (i < size)
 			{
 				exc := self basicAt: i.
@@ -372,6 +363,14 @@ thisContext isExceptionContext dump.
 		^self value.
 	}
 
+	method on: exc1 do: blk1 on: exc2 do: blk2 on: exc3 do: blk3
+	{
+		| exception_active |
+		<exception>
+		exception_active := true.
+		^self value.
+	}
+	
 	method ensure: aBlock
 	{
 		| retval pending |
@@ -394,6 +393,12 @@ thisContext isExceptionContext dump.
 		[ v := self value. pending := false. ] ensure: [ if (pending) { aBlock value } ].
 		^v.
 	}
+
+	method catch
+	{
+		^self on: Exception do: [:ex | ex ] 
+		      on: Error do: [:err | err ].
+	}
 }
 
 
@@ -440,10 +445,6 @@ class NotImplementedException(Exception)
 {
 }
 
-class ErrorExceptionizationFailureException(Exception)
-{
-}
-
 class InvalidArgumentException(Exception)
 {
 }
@@ -452,14 +453,6 @@ class ProhibitedMessageException(Exception)
 {
 }
 
-(*
-pooldic ErrorToException
-{
-	ErrorCode.EINVAL := InvalidArgumentException.
-	ErrorCode.ENOIMPL := NotImplementedException.
-}
-*)
-
 extend Apex
 {
 	method(#dual,#liberal) primitiveFailed(method)