XsemanticsScopeProvider.java

/*
 * generated by Xtext
 */
package it.xsemantics.dsl.scoping;

import it.xsemantics.dsl.util.XsemanticsUtils;
import it.xsemantics.dsl.xsemantics.CheckRule;
import it.xsemantics.dsl.xsemantics.JudgmentDescription;
import it.xsemantics.dsl.xsemantics.Rule;
import it.xsemantics.dsl.xsemantics.RuleInvocation;

import java.util.Collections;
import java.util.List;

import org.eclipse.emf.ecore.EObject;
import org.eclipse.xtext.scoping.IScope;
import org.eclipse.xtext.scoping.Scopes;
import org.eclipse.xtext.xbase.XBlockExpression;
import org.eclipse.xtext.xbase.XExpression;
import org.eclipse.xtext.xbase.XVariableDeclaration;
import org.eclipse.xtext.xbase.scoping.LocalVariableScopeContext;
import org.eclipse.xtext.xbase.scoping.XbaseScopeProvider;
import org.eclipse.xtext.xbase.scoping.featurecalls.IValidatedEObjectDescription;
import org.eclipse.xtext.xbase.scoping.featurecalls.JvmFeatureScope;
import org.eclipse.xtext.xbase.validation.IssueCodes;

import com.google.common.collect.Lists;
import com.google.inject.Inject;

/**
 * This class contains custom scoping description.
 * 
 * see : http://www.eclipse.org/Xtext/documentation/latest/xtext.html#scoping on
 * how and when to use it
 * 
 */
@SuppressWarnings("restriction")
public class XsemanticsScopeProvider extends XbaseScopeProvider {
	@Inject
	protected XsemanticsUtils utils;

	@Override
	protected IScope createLocalVarScope(IScope parentScope,
			LocalVariableScopeContext scopeContext) {
		parentScope = super.createLocalVarScope(parentScope, scopeContext);

		if (scopeContext != null && scopeContext.getContext() != null) {
			EObject context = scopeContext.getContext();
			if (context instanceof Rule) {
				parentScope = Scopes.scopeFor(
						utils.getJvmParameters((Rule) context), parentScope);
			} else if (context instanceof CheckRule) {
				CheckRule checkRule = (CheckRule) context;
				parentScope = Scopes.scopeFor(Collections
						.singletonList(checkRule.getElement().getParameter()),
						parentScope);
			} else if (context instanceof JudgmentDescription) {
				parentScope = Scopes.scopeFor(
						utils.getJvmParameters((JudgmentDescription) context),
						parentScope);
			}
		}

		return parentScope;
	}

	@Override
	protected IScope createLocalVarScopeForBlock(XBlockExpression block,
			int indexOfContextExpressionInBlock, boolean referredFromClosure,
			IScope parentScope) {
		// copied from XbaseScopeProvider with the case for RuleInvocation's
		// variable declarations
		List<IValidatedEObjectDescription> descriptions = Lists.newArrayList();
		for (int i = 0; i < indexOfContextExpressionInBlock; i++) {
			XExpression expression = block.getExpressions().get(i);
			if (expression instanceof XVariableDeclaration) {
				XVariableDeclaration varDecl = (XVariableDeclaration) expression;
				addVariableDeclaration(descriptions, varDecl,
						referredFromClosure);
			} else if (expression instanceof RuleInvocation) {
				RuleInvocation ruleInvocation = (RuleInvocation) expression;
				List<XVariableDeclaration> variableDeclarations = utils
						.getVariableDeclarations(ruleInvocation);
				for (XVariableDeclaration varDecl : variableDeclarations) {
					addVariableDeclaration(descriptions, varDecl,
							referredFromClosure);
				}
			}
		}
		if (descriptions.isEmpty())
			return parentScope;
		return new JvmFeatureScope(parentScope, "XBlockExpression",
				descriptions);
	}

	protected void addVariableDeclaration(
			List<IValidatedEObjectDescription> descriptions,
			XVariableDeclaration varDecl, boolean referredFromClosure) {
		if (varDecl.getName() != null) {
			IValidatedEObjectDescription desc = createLocalVarDescription(varDecl);
			if (referredFromClosure && varDecl.isWriteable())
				desc.setIssueCode(IssueCodes.INVALID_MUTABLE_VARIABLE_ACCESS);
			descriptions.add(desc);
		}
	}
}