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Bug 342173

Summary:	[Xtend] Improve return type inference for recursive methods
Product:	[Tools] Xtend	Reporter:	Robert von Massow <rvonmassow>
Component:	Core	Assignee:	Project Inbox <xtend-inbox>
Status:	CLOSED DUPLICATE	QA Contact:
Severity:	enhancement
Priority:	P3	CC:	btickets, dennis.huebner, jan, karsten.thoms, moritz.eysholdt, sebastian.zarnekow, sven.efftinge
Version:	2.2.0
Target Milestone:	---
Hardware:	PC
OS:	Linux
Whiteboard:
Bug Depends on:	376037
Bug Blocks:

Description Robert von Massow

2011-04-07 10:53:11 EDT

Build Identifier: 201104061304

I have the following Xtend dispatch function:

dispatch labelName(AbstractSection aS){
	aS.eContainer().labelName() + "-"
}

dispatch labelName(Object any){
	""
}

The editor complains here:

Couldn't resolve reference to JvmIdentifiableElement '+'. 

Also the whole function "labelName(AbstractSection aS)" is evaluated to be of type void, which is actually not the case.

Reproducible: Always

Comment 1 Sven Efftinge

2011-04-07 11:00:29 EDT

Because there is a recursion involved, you need to explicitly declare the return type (defaults to Object).
We need to add a validation.

Comment 2 Sebastian Zarnekow

2011-05-04 06:11:38 EDT

Preliminary scheduled for 2.0RC1

Comment 3 Sven Efftinge

2011-05-04 09:59:09 EDT

postponed to SR1

Comment 4 Sebastian Zarnekow

2011-07-21 04:30:47 EDT

*** Bug 352706 has been marked as a duplicate of this bug. ***

Comment 5 Jan Koehnlein

2011-10-14 07:25:55 EDT

If we want to solve this for all cases, this requires a significant amount of static code analysis which is not yet there. Postponed.

Comment 6 Dennis Huebner

2013-02-13 03:43:37 EST

Partially valid.

Actually:
- return type is now Object instead of void
- we have validation (warning message)

Should:
- return type should be String


Example:
	dispatch def labelName(EObject eObj) {// WARNING
		eObj.eContainer.labelName() + "_"
	}
	
	
	dispatch def labelName(Object obj) { //WARNING
		""
	}
	
	def test342173() {
		val eObj = EcoreFactory::eINSTANCE.createEObject
		val String str = eObj.labelName() //ERROR 
	}

Comment 7 Sven Efftinge

2013-09-13 05:30:21 EDT


*** This bug has been marked as a duplicate of bug 404817 ***