Completion refactoring: no result set exposed in wrapper

idea/src/org/jetbrains/jet/plugin/completion/CompletionResultSetWrapper.kt

@@ -21,20 +21,21 @@ import com.intellij.codeInsight.completion.InsertionContext
 import com.intellij.codeInsight.lookup.LookupElement
 import com.intellij.codeInsight.lookup.LookupElementDecorator
 import com.intellij.codeInsight.lookup.LookupElementPresentation
-import com.intellij.openapi.util.Condition
 import org.jetbrains.jet.lang.descriptors.DeclarationDescriptor
 import org.jetbrains.jet.lang.descriptors.FunctionDescriptor
-import org.jetbrains.jet.lang.resolve.BindingContext
 import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns
 import org.jetbrains.jet.plugin.completion.handlers.*
 import org.jetbrains.jet.plugin.project.ResolveSessionForBodies
+import com.intellij.codeInsight.completion.PrefixMatcher
 
-class CompletionResultSetWrapper(public val resultSet: CompletionResultSet,
+class CompletionResultSetWrapper(private val resultSet: CompletionResultSet,
                                  private val resolveSession: ResolveSessionForBodies,
                                  private val descriptorFilter: (DeclarationDescriptor) -> Boolean) {
     public var isSomethingAdded: Boolean = false
         private set
 
+    public val prefixMatcher: PrefixMatcher = resultSet.getPrefixMatcher()
+
     public fun addDescriptorElements(descriptors: Iterable<DeclarationDescriptor>) {
         for (descriptor in descriptors) {
             addDescriptorElements(descriptor)
@@ -72,7 +73,7 @@ class CompletionResultSetWrapper(public val resultSet: CompletionResultSet,
     }
 
     public fun addElement(element: LookupElement) {
-        if (resultSet.getPrefixMatcher().prefixMatches(element)) {
+        if (prefixMatcher.prefixMatches(element)) {
             resultSet.addElement(element)
             isSomethingAdded = true
         }

idea/src/org/jetbrains/jet/plugin/completion/CompletionSession.kt

@@ -43,15 +43,13 @@ class CompletionSession(public val parameters: CompletionParameters,
 
     private val inDescriptor: DeclarationDescriptor? = bindingContext.get(BindingContext.RESOLUTION_SCOPE, jetReference.expression)?.getContainingDeclaration()
 
-    public val result: CompletionResultSetWrapper = run {
-        // set prefix matcher here to override default one which relies on CompletionUtil.findReferencePrefix()
-        // which sometimes works incorrectly for Kotlin
-        var result = resultSet.withPrefixMatcher(CompletionUtil.findJavaIdentifierPrefix(parameters))
+    // set prefix matcher here to override default one which relies on CompletionUtil.findReferencePrefix()
+    // which sometimes works incorrectly for Kotlin
+    private val resultSet = resultSet
+            .withPrefixMatcher(CompletionUtil.findJavaIdentifierPrefix(parameters))
+            .addKotlinSorting(parameters)
 
-        result = result.addKotlinSorting(parameters)
-
-        CompletionResultSetWrapper(result, resolveSession, { isVisibleDescriptor(it) })
-    }
+    public val result: CompletionResultSetWrapper = CompletionResultSetWrapper(this.resultSet, resolveSession, { isVisibleDescriptor(it) })
 
     public fun completeForReference() {
         assert(parameters.getCompletionType() == CompletionType.BASIC)
@@ -64,7 +62,7 @@ class CompletionSession(public val parameters: CompletionParameters,
             }
             else {
                 addReferenceVariants { isPartOfTypeDeclaration(it) }
-                JavaCompletionContributor.advertiseSecondCompletion(parameters.getPosition().getProject(), result.resultSet)
+                JavaCompletionContributor.advertiseSecondCompletion(parameters.getPosition().getProject(), resultSet)
             }
 
             return
@@ -72,7 +70,7 @@ class CompletionSession(public val parameters: CompletionParameters,
 
         addReferenceVariants { true }
 
-        val prefix = result.resultSet.getPrefixMatcher().getPrefix()
+        val prefix = result.prefixMatcher.getPrefix()
 
         // Try to avoid computing not-imported descriptors for empty prefix
         if (prefix.isEmpty()) {
@@ -106,7 +104,7 @@ class CompletionSession(public val parameters: CompletionParameters,
     private fun addJetExtensions() {
         val project = position.getProject()
         val namesCache = JetShortNamesCache.getKotlinInstance(project)
-        result.addDescriptorElements(namesCache.getJetCallableExtensions({ result.resultSet.getPrefixMatcher().prefixMatches(it!!) }, jetReference.expression, resolveSession, GlobalSearchScope.allScope(project)))
+        result.addDescriptorElements(namesCache.getJetCallableExtensions({ result.prefixMatcher.prefixMatches(it!!) }, jetReference.expression, resolveSession, GlobalSearchScope.allScope(project)))
     }
 
     private fun isPartOfTypeDeclaration(descriptor: DeclarationDescriptor): Boolean {
@@ -124,7 +122,7 @@ class CompletionSession(public val parameters: CompletionParameters,
     }
 
     private fun addJetTopLevelFunctions() {
-        val actualPrefix = result.resultSet.getPrefixMatcher().getPrefix()
+        val actualPrefix = result.prefixMatcher.getPrefix()
         val project = position.getProject()
         val namesCache = JetShortNamesCache.getKotlinInstance(project)
         val scope = GlobalSearchScope.allScope(project)
@@ -145,7 +143,7 @@ class CompletionSession(public val parameters: CompletionParameters,
         val objectNames = namesCache.getAllTopLevelObjectNames()
 
         for (name in objectNames) {
-            if (result.resultSet.getPrefixMatcher().prefixMatches(name)) {
+            if (result.prefixMatcher.prefixMatches(name)) {
                 result.addDescriptorElements(namesCache.getTopLevelObjectsByName(name, jetReference.expression, resolveSession, scope))
             }
         }
@@ -177,7 +175,7 @@ class CompletionSession(public val parameters: CompletionParameters,
     }
 
     private fun shouldRunExtensionsCompletion(): Boolean {
-        return parameters.getInvocationCount() > 1 || result.resultSet.getPrefixMatcher().getPrefix().length >= 3
+        return parameters.getInvocationCount() > 1 || result.prefixMatcher.getPrefix().length >= 3
     }
 
     private fun addReferenceVariants(filterCondition: (DeclarationDescriptor) -> Boolean) {

idea/src/org/jetbrains/jet/plugin/completion/TypesCompletion.kt

@@ -41,7 +41,7 @@ class TypesCompletion(val parameters: CompletionParameters, val resolveSession:
 
         val project = parameters.getOriginalFile().getProject()
         val namesCache = JetShortNamesCache.getKotlinInstance(project)
-        result.addDescriptorElements(namesCache.getJetClassesDescriptors({ result.resultSet.getPrefixMatcher().prefixMatches(it!!) }, resolveSession, GlobalSearchScope.allScope(project)))
+        result.addDescriptorElements(namesCache.getJetClassesDescriptors({ result.prefixMatcher.prefixMatches(it!!) }, resolveSession, GlobalSearchScope.allScope(project)))
 
         if (!ProjectStructureUtil.isJsKotlinModule(parameters.getOriginalFile() as JetFile)) {
             addAdaptedJavaCompletion(result)
@@ -52,7 +52,7 @@ class TypesCompletion(val parameters: CompletionParameters, val resolveSession:
      * Add java elements with performing conversion to kotlin elements if necessary.
      */
     private fun addAdaptedJavaCompletion(result: CompletionResultSetWrapper) {
-        JavaClassNameCompletionContributor.addAllClasses(parameters, false, result.resultSet.getPrefixMatcher(), object : Consumer<LookupElement> {
+        JavaClassNameCompletionContributor.addAllClasses(parameters, false, result.prefixMatcher, object : Consumer<LookupElement> {
             override fun consume(lookupElement: LookupElement?) {
                 if (lookupElement is JavaPsiClassReferenceElement) {
                     val psiClass = lookupElement.getObject()