rewrite sequence in terms of foreverStIf to not leak memory

Libraries/iTasks/WF/Combinators/Common.dcl

@@ -147,13 +147,12 @@ justdo	:: !(Task (Maybe a)) -> Task a | iTask a
 /**
 * Execute the list of tasks one after another.
 * 
-* @param Label: A label for tracing
 * @param Tasks: The list of tasks to be executed sequentially
 * @return The combined task
 * 
 * @gin-icon sequence
 */
-sequence	:: !String ![Task a] 						-> Task [a]		| iTask a
+sequence	:: ![Task a] 						-> Task [a]		| iTask a
 
 /**
 * Repeats a task until a given predicate holds. The predicate is tested as soon as the

Libraries/iTasks/WF/Combinators/Common.icl

@@ -90,11 +90,17 @@ justdo task
 	Just x	= return x
 	Nothing	= throw ("The task returned nothing.")
 
-sequence :: !String ![Task a]  -> Task [a] | iTask a
-sequence _ tasks = seqTasks tasks
-where
-	seqTasks []		= return []
-	seqTasks [t:ts]	= t >>- \a -> seqTasks ts >>- \as -> return [a:as]
+sequence :: ![Task a]  -> Task [a] | iTask a
+sequence tasks = foreverStIf
+	//Continue while there are tasks left
+	(not o isEmpty o snd)
+	//Initial state, empty accumulator, all tasks
+	([], tasks)
+	//Run the first task and add it to the accumulator
+	(\(acc, [todo:todos])->todo >>- \t->treturn ([t:acc], todos))
+	//When done, just return the accumulator
+	@ fst
+	
 
 foreverStIf :: (a -> Bool) a !(a -> Task a) -> Task a | iTask a
 foreverStIf pred st t = parallel [(Embedded, par st Nothing)] []