Add cache to importedModulesResolved

Author: sungshik

src/org/rascalmpl/interpreter/env/ModuleEnvironment.java

@@ -90,6 +90,7 @@ public class ModuleEnvironment extends Environment {
 	private Map<String, AbstractFunction> resourceImporters;
 	private Map<Type, Set<GenericKeywordParameters>> cachedGeneralKeywordParameters;
 	private Map<String, List<AbstractFunction>> cachedPublicFunctions;
+	private List<ModuleEnvironment> cachedImportedModulesResolved;
 
 	private static final TypeFactory TF = TypeFactory.getInstance();
 
@@ -109,6 +110,7 @@ public ModuleEnvironment(String name, GlobalEnvironment heap) {
 		this.resourceImporters = new HashMap<String, AbstractFunction>();
 		this.cachedGeneralKeywordParameters = null;
 		this.cachedPublicFunctions = null;
+		this.cachedImportedModulesResolved = null;
 	}
 
 	@Override
@@ -127,12 +129,14 @@ public void reset() {
 		this.generalKeywordParameters = new HashMap<>();
 		this.cachedGeneralKeywordParameters = null;
 		this.cachedPublicFunctions = null;
+		this.cachedImportedModulesResolved = null;
 	}
 
 	public void clearLookupCaches() {
 		importedModules.replaceAll((k, v) -> Optional.empty());
 		cachedGeneralKeywordParameters = null;
 		cachedPublicFunctions = null;
+		cachedImportedModulesResolved = null;
 	}
 
 	/**
@@ -382,12 +386,14 @@ public void addImport(String name, ModuleEnvironment env) {
 		typeStore.importStore(env.typeStore);
 		this.cachedGeneralKeywordParameters = null;
 		this.cachedPublicFunctions = null;
+		this.cachedImportedModulesResolved = null;
 	}
 
 	void removeModule(String name) {
 		importedModules.computeIfPresent(name, (k, v) -> Optional.empty());
 		this.cachedGeneralKeywordParameters = null;
 		this.cachedPublicFunctions = null;
+		this.cachedImportedModulesResolved = null;
 	}
 
 	public void addExtend(String name) {
@@ -397,6 +403,7 @@ public void addExtend(String name) {
 		extended.add(name);
 		this.cachedGeneralKeywordParameters = null;
 		this.cachedPublicFunctions = null;
+		this.cachedImportedModulesResolved = null;
 	}
 
 	public List<AbstractFunction> getTests() {
@@ -453,6 +460,7 @@ public void unImport(String moduleName) {
 		}
 		cachedGeneralKeywordParameters = null;
 		cachedPublicFunctions = null;
+		cachedImportedModulesResolved = null;
 	}
 
 	public void unExtend(String moduleName) {
@@ -885,6 +893,17 @@ public ModuleEnvironment getImport(String moduleName) {
 	}
 
 	private Iterable<ModuleEnvironment> importedModulesResolved = 
+		() -> getImportedModulesResolved().iterator();
+
+	private List<ModuleEnvironment> getImportedModulesResolved() {
+		if (cachedImportedModulesResolved == null) {
+			cachedImportedModulesResolved = new ArrayList<>();
+			importedModulesResolver.forEach(cachedImportedModulesResolved::add);
+		}
+		return cachedImportedModulesResolved;
+	}
+
+	private Iterable<ModuleEnvironment> importedModulesResolver = 
 		() -> new Iterator<ModuleEnvironment>() {
 			Iterator<Entry<String, Optional<ModuleEnvironment>>> iterator = importedModules.entrySet().iterator();
 			@Override