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Error on first generation regarding superType [message #1792763]

Mon, 23 July 2018 15:43

Karsten Wilken

Messages: 50
Registered: August 2016

Member

With the DSL I create a number of subclasses instead of a single class for each needed class. In the example I only created one subclass but in the real usecase for DSL there could be too many to create an own class for each one. (thats the reason why I attempt to create subclasses)

The error only appears on the first code generation. Instead of the expected
"class A extends B"
Xtext generates
"class A implements B"

After the second code generation it works as expected.

The issue appears with the "IdWithKeyElementInferrerExtension" (part of the inferrer).

With the following method I could fix the problem with the generated class(container for the subclasses) itself:

void IJvmDeclaredTypeAcceptor.accept(JvmGenericType type, Procedure1<? super JvmGenericType> lateInitialization)

acceptor.accept(
		element.toClass(element.name) [
			packageName = element.packageName
			[...]
		],
		[superTypes += BaseClass.typeRef
		])

But I have no clue how or if it is possible to set the inheritance reference for the subclasses in the "lateInitialization".

Example project is in the attachments.

Attachment: example.parent.zip
(Size: 1.54MB, Downloaded 12 times)
Attachment: TestExample.zip
(Size: 9.52KB, Downloaded 11 times)

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Re: Error on first generation regarding superType [message #1792767 is a reply to message #1792763]

Mon, 23 July 2018 16:13

Christian Dietrich

Messages: 12373
Registered: July 2009

Senior Member

hi

please please provide minimal samples if you ask for help.

your inferrer pattern looks wired.

the default pattern is

acceptor.accecpt(element.toClass()) [
// late init
]
you can reference the outer class like this

 val outer = it
				if (!element.valueClasses.isEmpty) {
					for (vClass : element.valueClasses) {
						val className = vClass.name.toCamelCase
						members += element.toClass(className) [
							static = true
							//TODO 
							superTypes += outer.typeRef

or you dont use that wired wired pattern for names

acceptor.accept(
element.toClass(element.packageName + "." +element.name)) [
....

superTypes += (element.packageName + "." +element.name) .typeRef

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Re: Error on first generation regarding superType [message #1792800 is a reply to message #1792767]

Tue, 24 July 2018 09:23

Karsten Wilken

Messages: 50
Registered: August 2016

Member

I included the projects rather than parts of the code since I had no clue which part could case this behaviour.
After I changed the inferrer back to the default pattern and used the "outer" reference the "extends" is created correctly.

I use the weird name pattern "(element.packageName + "." +element.name) .typeRef" only within the acceptor for the visitor class for the parameter within the "toMethod".
If I simply use the name of the "valueClass" alone the reference doesn't get resolved.

		acceptor.accept(element.toClass(visitor)) [
			packageName = element.packageName
			interface = true
			for (vClass : element.valueClasses) {
				val vName = vClass.name.toCamelCase
				members += element.toMethod("visit" + vName, typeRef("void")) [
					abstract = true
					parameters += toParameter(
						vClass,
						"value",
						vName.typeRef
					)
				]
			}
		]

This leads to the generated code:

public abstract void visitSubClassOne(final SubClassOne value);

With the error that SubClassOne couldn't be resolved. (most likely because it is a subclass of the "parent" class)

If I use the weird name pattern:

		acceptor.accept(element.toClass(visitor)) [
			packageName = element.packageName
			interface = true
			for (vClass : element.valueClasses) {
				val vName = vClass.name.toCamelCase
				members += element.toMethod("visit" + vName, typeRef("void")) [
					abstract = true
					parameters += toParameter(
						vClass,
						"value",
						(element.fullyQualifiedName.toString + "." + vName).typeRef
					)
				]
			}
		]

This method gets generated:

public abstract void visitSubClassOne(final ParentClass.SubClassOne value);

Not ideal but since it is in the same package at least it worked.

The implicit question is: What would be the correct way to reference a subclass?

[Updated on: Tue, 24 July 2018 09:25]

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Re: Error on first generation regarding superType [message #1792824 is a reply to message #1792800]

Tue, 24 July 2018 13:41

Christian Dietrich

Messages: 12373
Registered: July 2009

Senior Member

so i said: use "(element.packageName + "." +element.name) .typeRef" everywhere

for the inner class please try path.to.Outer$Inner

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Re: Error on first generation regarding superType [message #1792830 is a reply to message #1792767]

Tue, 24 July 2018 14:13

Karsten Wilken

Messages: 50
Registered: August 2016

Member

Christian Dietrich wrote on Mon, 23 July 2018 16:13

[...]
or you dont use that wired wired pattern for names

acceptor.accept(
element.toClass(element.packageName + "." +element.name)) [
....

superTypes += (element.packageName + "." +element.name) .typeRef

Ok, sry! Missunderstood your response. Thought I should NOT use it.

The obvious answer for the subclass is almost embarrassing :D
(element.packageName + "." +element.name + "." + {classNameHere}).typeRef

Sometimes you are so fixed in your perspective that you don't see the simple solution. :(

Thank you very much!

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Re: Error on first generation regarding superType [message #1793970 is a reply to message #1792824]

Tue, 21 August 2018 11:53

Karsten Wilken

Messages: 50
Registered: August 2016

Member

Christian Dietrich wrote on Tue, 24 July 2018 13:41

so i said: use "(element.packageName + "." +element.name) .typeRef" everywhere

for the inner class please try path.to.Outer$Inner

I got a follow up question regarding the syntax of the inner classes reference.

At the moment I'm trying to extend from inner classes.
The goal is to create stubs once for further non-generated custom code. (Generation Gap)

As a little overview:

interface I
	
abstract class A implements I {
	abstract class B extends A
	abstract class C extends A
}

class BImpl extends B {
}

Within the inferrer I use this part to generate the "Impl" classes and set the supertype:

for(vClass: element.valueClasses) {
	acceptor.accept(element.toClass(vClass.name +"Impl")) [
		packageName = element.packageName
					
		superTypes += (element.packageName + "." + element.name + "." + vClass.name).typeRef
		members += element.toField("test", String.typeRef)
	]
}

This is the reduced example I used to try to fix the extends "issues". (If you are wondering why there is no OutputConfigurationAdapter for the "generate once" part)

If I edit the generated file and change the implements back to extends all seems fine and it can be resolved. Therefore I guess XText cannot find or know the inner class during the generation?

The pattern "(element.packageName + "." + element.name + "." + vClass.name).typeRef" works in the method context:

for (vClass : element.valueClasses) {
	val vName = vClass.name.toCamelCase
	members += element.toMethod("visit" + vName, void.typeRef) [
		abstract = true
		parameters += vClass.toParameter("value", (element.packageName + "." + element.name+ "." + vName).typeRef)
	]
}

I hope I provided enough context without an updated example project.

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Re: Error on first generation regarding superType [message #1793971 is a reply to message #1793970]

Tue, 21 August 2018 11:59

Christian Dietrich

Messages: 12373
Registered: July 2009

Senior Member

no please provide a hello world grammar and inferrer showing the problem

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Re: Error on first generation regarding superType [message #1793973 is a reply to message #1793971]

Tue, 21 August 2018 12:07

Christian Dietrich

Messages: 12373
Registered: July 2009

Senior Member


Model:
	"model" name=ID;

	def dispatch void infer(Model element, IJvmDeclaredTypeAcceptor acceptor, boolean isPreIndexingPhase) {
		acceptor.accept(element.toClass("dummy.Outer")) [
			members+=element.toClass("Inner1") [
				static = true
			]
			members+=element.toClass("Inner2") [
				static = true
			]
		]
		acceptor.accept(element.toClass("dummy.Outer2")) [
			superTypes+="dummy.Outer$Inner1".typeRef
		]
	}

works fine for me

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Re: Error on first generation regarding superType [message #1793974 is a reply to message #1793971]

Tue, 21 August 2018 12:26

Karsten Wilken

Messages: 50
Registered: August 2016

Member

Well. Nevermind. The one thing I didn't try was taking your "suggestion"/answer literally!

"path.to.Outer$Inner " was the solution.
Instead of "(element.packageName + "." + element.name + "." + vClass.name).typeRef" I tried this during building the example
"(element.packageName + "." + element.name + "$" + vClass.name).typeRef" and it works.

Edit: And again, you are faster as usual ;)

[Updated on: Tue, 21 August 2018 12:48]

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Re: Error on first generation regarding superType [message #1794286 is a reply to message #1793974]

Tue, 28 August 2018 13:03

Karsten Wilken

Messages: 50
Registered: August 2016

Member

This is a simplified version of my Xtext project with the same extends/implements "error".

I have no clue how to fix it. Like I stated above, I had a working solution but for some reason that I can't figure out the generation now fails.

For the context how I "test" the generation:
* Delete the generated package by hand
* Add a single character/comment or whitespace to the dsl and save it.

Attachment: simpleExample.parent.zip
(Size: 1.39MB, Downloaded 8 times)
Attachment: SimpleImplExample.zip
(Size: 3.18KB, Downloaded 6 times)

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Re: Error on first generation regarding superType [message #1794299 is a reply to message #1794286]

Tue, 28 August 2018 15:22

Christian Dietrich

Messages: 12373
Registered: July 2009

Senior Member

again. already have you the answer before

bad:

acceptor.accept(element.toClass(element.name + implExtention)) [
packageName=package

good:

acceptor.accept(element.toClass(package + "." + element.name + implExtention)) [

Need professional support for Xtext, Xpand, EMF?
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Blog : https://www.dietrich-it.de

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Re: Error on first generation regarding superType [message #1794398 is a reply to message #1794299]

Thu, 30 August 2018 09:46

Karsten Wilken

Messages: 50
Registered: August 2016

Member

Thank you very much! In the small example this looks stupid.. but it was the last toClass where I didn't change it and just c&p it to the example.

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