Eclipse Community Forums: TMF (Xtext) » appendArguments(..) generating comments instead of content

Home

Home » Modeling » TMF (Xtext) » appendArguments(..) generating comments instead of content

appendArguments(..) generating comments instead of content [message #1742541]

Sat, 03 September 2016 20:13

Eclipse User

I have the following grammar (snippets of):

Action:
	'action' name=ID '(' actionFormalParameters=FormalParameters ')' '=' action=ActionBlock;

ActionBlock returns xbase::XBlockExpression:
	'{'
	{ActionBlock} 
	(expressions+=ActionBlockStatement ';'?)*
	'}';

ActionBlockStatement returns xbase::XExpression:
	ActionRefInvocation | XExpressionOrVarDeclaration;

ActionRefInvocation:
	actionRef=ActionRef '(' actionActualParameters=ActualParameters ')';

ActionRef hidden():
	'#' actionRefId=[Action];

In other words, I want to be able to do something like this:

    action a(String s) = {
    		println(s)
    }
    
    action b(String s) = {
    		#a(s)
    }

In my compiler that extends XbaseCompiler, I have the following function to handle ActionRefInvocation:

override protected doInternalToJavaStatement(XExpression obj, ITreeAppendable appendable, boolean isReferenced) {
		if (obj instanceof ActionRefInvocation) {
			appendable.trace(obj)
			appendable.newLine
			
			val action = obj.actionRef.actionRefId
			val actionParameters = obj.actionActualParameters
			val actionClass = action.jvmElements.filter(JvmGenericType).filter[t|!t.isInterface].head
			val objectName = "action" + uuidName
			
			appendable.append('''«actionClass.fullyQualifiedName» «objectName» = new «actionClass.fullyQualifiedName»();''')
			appendable.newLine
			
			appendable.append('''«objectName».accept(''')
			appendable.newLine
			
			appendArguments(actionParameters.parameters, appendable)
			
			appendable.append(");")
			appendable.newLine
			
			appendable.newLine
			return
		}

		super.doInternalToJavaStatement(obj, appendable, isReferenced)
	}

But the output I get from the compilation is the following, which of course does not compile because the function implementation of a expects a String argument.

public void accept(final int i) {
    valour.documentation.actions.Action6 action07f90ee2b6004c4fb226bbe61c58c88f = new valour.documentation.actions.Action6();
    action07f90ee2b6004c4fb226bbe61c58c88f.accept(
    /* name is null */);
  }

Also, I've noticed that if I change the example supplied above to:

    action a(String s) = {
    		println(s)
    }
    
    action b() = {
    		#a("foo")
    }

I get the following null pointer exception on the invocation of appendArguments(..)

!STACK 0
java.lang.NullPointerException
	at org.eclipse.xtext.xbase.compiler.LiteralsCompiler.toJavaExpression(LiteralsCompiler.java:81)
	at org.eclipse.xtext.xbase.compiler.LiteralsCompiler._toJavaExpression(LiteralsCompiler.java:73)
	at org.eclipse.xtext.xbase.compiler.LiteralsCompiler.internalToConvertedExpression(LiteralsCompiler.java:41)
	at org.eclipse.xtext.xbase.compiler.FeatureCallCompiler.internalToConvertedExpression(FeatureCallCompiler.java:102)
	at org.eclipse.xtext.xbase.compiler.XbaseCompiler.internalToConvertedExpression(XbaseCompiler.java:317)
	at org.eclipse.xtext.xbase.compiler.TypeConvertingCompiler.internalToConvertedExpression(TypeConvertingCompiler.java:104)
	at org.eclipse.xtext.xbase.compiler.TypeConvertingCompiler.internalToJavaExpression(TypeConvertingCompiler.java:47)
	at org.eclipse.xtext.xbase.compiler.FeatureCallCompiler.appendArgument(FeatureCallCompiler.java:1033)
	at org.eclipse.xtext.xbase.compiler.FeatureCallCompiler.appendArguments(FeatureCallCompiler.java:995)
	at org.eclipse.xtext.xbase.compiler.FeatureCallCompiler.appendArguments(FeatureCallCompiler.java:989)
	at mt.edu.um.cs.rv.ValourCompiler.doInternalToJavaStatement(ValourCompiler.java:70)

I'm not sure what I'm doing wrong here. I would appreciate your help.

Thanks

Re: appendArguments(..) generating comments instead of content [message #1742699 is a reply to message #1742541]

Tue, 06 September 2016 12:55

Eclipse User

What are your adoptions to inferrer and type computer?

Re: appendArguments(..) generating comments instead of content [message #1742702 is a reply to message #1742699]

Tue, 06 September 2016 12:59

Eclipse User

and how do the actual parameters look like.
and on what level do you use the actions? maybe a inferrer only solution would do the trick as well (with a silghtly different syntax)

Re: appendArguments(..) generating comments instead of content [message #1743471 is a reply to message #1742702]

Thu, 15 September 2016 13:59

Eclipse User

Thanks for you reply Christian, and sorry for getting back late but was on vacation since.

In my inferrer, I am first creating an FunctionalInterface for the action

		val consumableFunctionalInterface = action.toClass(
			functionalInterfaceName,
			[
				annotations += annotationRef(FunctionalInterface)
				interface = true
				members += action.toMethod("accept", typeRef(void), [
					static = false
					^default = false
					abstract = true
					visibility = JvmVisibility.PUBLIC
					action.actionFormalParameters.parameters.forEach [ p |
						parameters += action.toParameter(p.name, p.parameterType)
					]
				])
			]
		)

and then creating an implementation of the FunctioanlInterface and plugging in the body of the action

		val actionClass = action.toClass(
			className,
			[
				superTypes += typeRef(functionalInterfaceName)

				members += action.toMethod("accept", typeRef(void), [
					static = false
					visibility = JvmVisibility.PUBLIC
					annotations += annotationRef(Override)
					action.actionFormalParameters.parameters.forEach [ p |
						parameters += action.toParameter(p.name, p.parameterType)
					]
					body = action.action
				])
			]
		)

I have not implemented anything in terms of the type computer. Is this something that I should be extending ?

My definition of ActualParameter is the following:

ActualParameters:
	{ActualParameters}(parameters+=XExpression (',' parameters+=XExpression)*)?;

Any guidance to help me get this set up in the proper way would be greatly appreciated.

Re: appendArguments(..) generating comments instead of content [message #1743474 is a reply to message #1743471]

Thu, 15 September 2016 14:17

Eclipse User

i was thinking of

Model:
	actions+=Action+
;

Action:
	'action' name=ID '(' (actionFormalParameters+=JvmFormalParameter (',' actionFormalParameters+=JvmFormalParameter)*) ')' '=' action=XBlockExpression;

	def dispatch void infer(Model model, IJvmDeclaredTypeAcceptor acceptor, boolean isPreIndexingPhase) {
		acceptor.accept(model.toClass("test.Demo")) [
			for (a : model.actions) {
				members += a.toMethod(a.name, Void.TYPE.typeRef) [
					body = a.action
					for (p : a.actionFormalParameters) {
						parameters+=p
					}
				]
			}
		]
	}

Re: appendArguments(..) generating comments instead of content [message #1743484 is a reply to message #1743474]

Thu, 15 September 2016 16:10

Eclipse User

Thanks for your quick reply.

My issue is not with defining an action but with having one action invoke another action, and my requirement is that action are referenced using a #.

In the example below, I don't have any issues with compiling action a. However, when compiling action b (which contains an ActionRefInvocation) I get the exception I mentioned in my first post.

    action a(String s) = {
    		println(s)
    }
    
    action b() = {
    		#a("foo")
    }

Re: appendArguments(..) generating comments instead of content [message #1743488 is a reply to message #1743484]

Thu, 15 September 2016 16:43

Eclipse User

Well as I said that is not that easy. In that case you have to compute the types correctly in your type computer

Re: appendArguments(..) generating comments instead of content [message #1743489 is a reply to message #1743488]

Thu, 15 September 2016 16:45

Eclipse User

Well how does your type computer for action ref and actual parameters look like?

Re: appendArguments(..) generating comments instead of content [message #1743491 is a reply to message #1743489]

Thu, 15 September 2016 17:32

Eclipse User

This is what I have so far for ActionRefInvocation. I am computing a void type as the invocation of actions will always return void.

    def dispatch computeTypes(ActionRefInvocation literal, ITypeComputationState state) {
        state.withoutExpectation
        state.acceptActualType(getPrimitiveVoid(state))
    }

I have not as yet written a type computer for ActualParameters as I'm not sure what to do here.

Re: appendArguments(..) generating comments instead of content [message #1743500 is a reply to message #1743491]

Fri, 16 September 2016 01:13

Eclipse User

you are missing to walk down into the actual params

public class MyDslTypeComputer extends XbaseTypeComputer {
	
	@Override
	public void computeTypes(XExpression expression, ITypeComputationState state) {
		if (expression instanceof ActionRefInvocation) {
			// TODO match formal and actual params in expectation (use expectation of formal param)
			for (XExpression ap : ((ActionRefInvocation) expression).getActionActualParameters().getParameters()) {
				state.withNonVoidExpectation().computeTypes(ap);
			}
			
			
			state.acceptActualType(getPrimitiveVoid(state));
			return;
		}
		super.computeTypes(expression, state);
	}

}

Re: appendArguments(..) generating comments instead of content [message #1743661 is a reply to message #1743500]

Sun, 18 September 2016 09:47

Eclipse User

That worked perfectly! Thanks for all your help!

Previous Topic:	How does the until rule works ?
Next Topic:	Multiple file support in IDEA plugin

Goto Forum:

-=] Back to Top [=-

Current Time: Mon Jul 28 15:45:59 EDT 2025

.:: Contact :: Home ::.

Breadcrumbs

Sign up to our Newsletter