Swift class resolver updates

1 files changed, 23 insertions, 40 deletions

diff --git a/swift/src/Ice/ClassResolver.swift b/swift/src/Ice/ClassResolver.swift
index fe573d1b41a..ba00502c0c7 100644
--- a/swift/src/Ice/ClassResolver.swift
+++ b/swift/src/Ice/ClassResolver.swift
@@ -9,58 +9,41 @@
 
 import Foundation
 
+open class ValueTypeResolver: NSObject {
+    open func type() -> Value.Type {
+        precondition(false, "Abstract method")
+    }
+}
+
+open class UserExceptionTypeResolver: NSObject {
+    open func type() -> UserException.Type {
+        precondition(false, "Abstract method")
+    }
+}
+
 //
-// Slice classes and exceptions extend Ice.ClassResolver with a static func
-// which returns the Swift Value.Type or UserException.Type.
-//
-// We subclass NSObject so that we can use selectors.
+// Slice classes and exceptions generate an extesion for
+// Ice.ClassResolver with a static func which returns a
+// ValueTypeRessolver or UserExceptionTypeRessolver.
 //
-// @objc dynamic Module_MyClass() -> Value.Type
 
 public class ClassResolver: NSObject {
-    private static func mangle(typeId: String) -> String {
-        precondition(typeId.count > 2, "invalid type id")
-
-        guard let r = typeId.range(of: "::") else {
-            preconditionFailure("invalid type id")
-        }
-
-        precondition(r.lowerBound == typeId.startIndex, "invalid type id")
-
-        let c = typeId.components(separatedBy: "::")[1...]
-        return c.joined(separator: "_")
-    }
-
-    static func resolve(typeId: String) -> Value.Type? {
-        let selector = Selector(mangle(typeId: typeId))
 
+    static private func resolveImpl(typeId: String) -> AnyObject? {
+        let start = typeId.index(typeId.startIndex, offsetBy: 2)
+        let selector = Selector(typeId[start...].replacingOccurrences(of: "::", with: "_"))
         guard ClassResolver.responds(to: selector) else {
             return nil
         }
+        return ClassResolver.perform(selector).takeUnretainedValue()
+    }
 
-        #warning("TODO: check this is correct wrt memory management")
-        let val = ClassResolver.perform(Selector(mangle(typeId: typeId))).takeRetainedValue()
-
-        guard let valueType = val as? Value.Type else {
-            preconditionFailure("unexpected value type")
-        }
-        return valueType
+    static func resolve(typeId: String) -> Value.Type? {
+        return (resolveImpl(typeId: typeId) as! ValueTypeResolver).type()
     }
 
     static func resolve(typeId: String) -> UserException.Type? {
-        let selector = Selector(mangle(typeId: typeId))
-
-        guard ClassResolver.responds(to: selector) else {
-            return nil
-        }
-
-        #warning("TODO: check this is correct wrt memory management")
-        let val = ClassResolver.perform(selector).takeRetainedValue()
-
-        guard let valueType = val as? UserException.Type else {
-            preconditionFailure("unexpected value type")
-        }
-        return valueType
+        return (resolveImpl(typeId: typeId) as! UserExceptionTypeResolver).type()
     }
 }