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Help with xtext grammar void method [message #813255]

Mon, 05 March 2012 03:02

Leonardo Torres

Messages: 16
Registered: March 2012

Junior Member

Hi guys,

If possible, I would like of an example or some tutorial of the grammar that define a void method.

Thanks in advance!

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Re: Help with xtext grammar void method [message #813626 is a reply to message #813255]

Mon, 05 March 2012 14:17

Henrik Lindberg

Messages: 2509
Registered: July 2009

Senior Member

Sorry, but I don't understand your question. What do you mean by "Xtext
void method" ?

- henrik

On 2012-05-03 4:02, Leonardo Torres wrote:
> Hi guys,
> If possible, I would like of an example or some tutorial of the grammar
> that define a void method.
>
>
> Thanks in advance!

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Re: Help with xtext grammar void method [message #813711 is a reply to message #813626]

Mon, 05 March 2012 16:28

Leonardo Torres

Messages: 16
Registered: March 2012

Junior Member

I´m sorry. Let me explain

I'm creating a DSL for Oriented Objetct teach purposes, so I can create rule for entities (class) properties (attibute) and method with return. However, I don´t know to create a rule for method without return. Thus, I would like of an exemple of the rule for a method without return.

Thank for help-me

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Re: Help with xtext grammar void method [message #813726 is a reply to message #813711]

Mon, 05 March 2012 16:38

Christian Dietrich

Messages: 14665
Registered: July 2009

Senior Member

Hat about simply makeing the return type optional in the grammar

Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

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Re: Help with xtext grammar void method [message #813791 is a reply to message #813726]

Mon, 05 March 2012 18:07

Leonardo Torres

Messages: 16
Registered: March 2012

Junior Member

Thanks for answer.

I did that :

Method:	
	 'operacao' name= ValidID '('(param+=FullJvmFormalParameter (','
	   param+=FullJvmFormalParameter)*)?') retorna' resultType = ResultType
	       body=XBlockExpression	    
;
ResultType :	
	NoResult | Result
;

NoResult:
	'nada'
;

Result :	 
	type=JvmTypeReference 
;

It is works! In the Editor:

operacao test() retorna nada{	        
        var int nome = 2;
    	return 2;		
}

Where can I validate the semantic ? Because in this case above, It´s wrong. The word 'nada' means no return, but I can still write the statement return.

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Re: Help with xtext grammar void method [message #813823 is a reply to message #813791]

Mon, 05 March 2012 18:55

Christian Dietrich

Messages: 14665
Registered: July 2009

Senior Member

Hi,

it would have been very helpful if youd mentione using Xbase before.
what you are askin for is about xbases type system.
if you translate your stuff correctly in the jvmmodelinferrer it will work out of the box.
so simply infer void as return type

NoResult:
	{NoResult}'nada'
;

package org.eclipse.xtext.example.domainmodel.jvmmodel

import com.google.inject.Inject
import org.eclipse.xtext.common.types.JvmDeclaredType
import org.eclipse.xtext.example.domainmodel.domainmodel.Entity
import org.eclipse.xtext.example.domainmodel.domainmodel.Operation
import org.eclipse.xtext.example.domainmodel.domainmodel.Property
import org.eclipse.xtext.naming.IQualifiedNameProvider
import org.eclipse.xtext.util.IAcceptor
import org.eclipse.xtext.xbase.jvmmodel.AbstractModelInferrer
import org.eclipse.xtext.xbase.jvmmodel.JvmTypesBuilder
import org.eclipse.xtext.example.domainmodel.domainmodel.Result

class DomainmodelJvmModelInferrer extends AbstractModelInferrer {
	
	@Inject extension JvmTypesBuilder
	@Inject extension IQualifiedNameProvider

	def dispatch infer(Entity e, IAcceptor<JvmDeclaredType> acceptor, boolean prelinkingPhase) {
		acceptor.accept(
			e.toClass( e.fullyQualifiedName ) [
				documentation = e.documentation
				if (e.superType != null)
					superTypes += e.superType.cloneWithProxies
					
				for ( f : e.features ) {
					switch f {
				
						Property : {
							members += f.toField(f.name, f.type)
							members += f.toGetter(f.name, f.type)
							members += f.toSetter(f.name, f.type)
						}
				
						Operation : {
							members += f.toMethod(f.name, if (f.result instanceof Result) (f.result as Result).type else f.newTypeRef("java.lang.void")) [
								documentation = f.documentation
								for (p : f.params) {
									parameters += p.toParameter(p.name, p.parameterType)
								}
								body = f.body
							]
						}
					}
				}
			]
		)
	}
	
}

this will work in the editor
but will still lead to a compile error in the generated java code (if the ops body is empty)
so a bug for this will be welcome

~Christian

Twitter : @chrdietrich
Blog : https://www.dietrich-it.de

[Updated on: Mon, 05 March 2012 18:56]

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Re: Help with xtext grammar void method [message #813845 is a reply to message #813823]

Mon, 05 March 2012 19:30

Leonardo Torres

Messages: 16
Registered: March 2012

Junior Member

Thanks for all answer.

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Re: Help with xtext grammar void method [message #813904 is a reply to message #813845]

Mon, 05 March 2012 20:51

Leonardo Torres

Messages: 16
Registered: March 2012

Junior Member

Just one more question. Are there any indication about xtext/xbase/xtend book´s ?

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Re: Help with xtext grammar void method [message #813909 is a reply to message #813823]

Mon, 05 March 2012 20:51

Sebastian Zarnekow

Messages: 3118
Registered: July 2009

Senior Member

Hi Christian,

f.newTypeRef("void")
instead of
f.newTypeRef("java.lang.void")

should do the trick.

Regards,
Sebastian
--
Need professional support for Eclipse Modeling?
Go visit: http://xtext.itemis.com

Am 05.03.12 19:56, schrieb Christian Dietrich:
> Hi,
>
> it would have been very helpful if youd mentione using Xbase before.
> what you are askin for is about xbases type system.
> if you translate your stuff correctly in the jvmmodelinferrer it will
> work out of the box.
> so simply infer void as return type
>
> NoResult:
> {NoResult}'nada'
> ;
>
> package org.eclipse.xtext.example.domainmodel.jvmmodel
>
> import com.google.inject.Inject
> import org.eclipse.xtext.common.types.JvmDeclaredType
> import org.eclipse.xtext.example.domainmodel.domainmodel.Entity
> import org.eclipse.xtext.example.domainmodel.domainmodel.Operation
> import org.eclipse.xtext.example.domainmodel.domainmodel.Property
> import org.eclipse.xtext.naming.IQualifiedNameProvider
> import org.eclipse.xtext.util.IAcceptor
> import org.eclipse.xtext.xbase.jvmmodel.AbstractModelInferrer
> import org.eclipse.xtext.xbase.jvmmodel.JvmTypesBuilder
> import org.eclipse.xtext.example.domainmodel.domainmodel.Result
>
> class DomainmodelJvmModelInferrer extends AbstractModelInferrer {
>
> @Inject extension JvmTypesBuilder
> @Inject extension IQualifiedNameProvider
>
> def dispatch infer(Entity e, IAcceptor<JvmDeclaredType> acceptor,
> boolean prelinkingPhase) {
> acceptor.accept(
> e.toClass( e.fullyQualifiedName ) [
> documentation = e.documentation
> if (e.superType != null)
> superTypes += e.superType.cloneWithProxies
>
> for ( f : e.features ) {
> switch f {
>
> Property : {
> members += f.toField(f.name, f.type)
> members += f.toGetter(f.name, f.type)
> members += f.toSetter(f.name, f.type)
> }
>
> Operation : {
> members += f.toMethod(f.name, if (f.result instanceof Result) (f.result
> as Result).type else f.newTypeRef("java.lang.void")) [
> documentation = f.documentation
> for (p : f.params) {
> parameters += p.toParameter(p.name, p.parameterType)
> }
> body = f.body
> ]
> }
> }
> }
> ]
> )
> }
>
> }
>
> this will work in the editor
> but will still lead to a compile error in the generated java code
> so a bug for this will be welcome
>
> ~Christian

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