[WIP] Add dynamic callable and member lookup

Sources/RubyGateway/RbGateway.swift

@@ -59,6 +59,7 @@ import RubyGatewayHelpers
 /// to define new classes and modules.  Then add methods using `RbObject.defineMethod(...)`
 /// and `RbObject.defineSingletonMethod(...)`.
 ///
+@dynamicMemberLookup
 public final class RbGateway: RbObjectAccess {
 
     /// The VM - not initialized until `setup()` is called.
@@ -358,6 +359,13 @@ extension RbGateway {
     }
 }
 
+// MARK: - Dynamic member lookup
+public extension RbGateway {
+    subscript(dynamicMember member: String) -> RbObject! {
+        try? `get`(member)
+    }
+}
+
 // MARK: - Global declaration
 
 /// The shared instance of `RbGateway`. :nodoc:

Sources/RubyGateway/RbObject.swift

@@ -85,6 +85,8 @@ import RubyGatewayHelpers
 /// Use `RbObject.defineMethod(...)` and `RbObject.defineSingletonMethod(...)` to
 /// add methods implemented in Swift to an object or class.  Use
 /// `RbGateway.defineClass(_:parent:under:)` to define entirely new classes.
+@dynamicMemberLookup
+@dynamicCallable
 public final class RbObject: RbObjectAccess {
     internal let valueBox: UnsafeMutablePointer<Rbg_value>
 
@@ -386,6 +388,51 @@ extension RbObject: Hashable, Equatable, Comparable {
     }
 }
 
+// MARK: - Dynamic member lookup and callable
+public extension RbObject {
+
+    subscript(dynamicMember memberName: String) -> RbObject! {
+        get {
+            if let member = try? get(memberName) {
+                return member
+            } else {
+                // Maybe it's a method
+                if let _ = try? memberName.checkRubyMethodName() {
+                        return try? call("method", args: [memberName])
+                } else {
+                    return nil
+                }
+            }
+        }
+        set {
+            if let _ = try? setAttribute(memberName, newValue: newValue) { return }
+            if let _ = try? setInstanceVar(memberName, newValue: newValue) { return }
+        }
+    }
+
+    @discardableResult
+    func dynamicallyCall(withArguments arguments: [RbObjectConvertible]) -> RbObject! {
+        switch rubyType {
+        case .T_CLASS:
+            do {
+                let newInstance = try call("new", args: arguments)
+                return newInstance.isNil ? nil : newInstance
+            } catch {
+                preconditionFailure("Couldn't create new instance of class")
+            }
+        case .T_DATA:
+            do {
+                let result = try call("call", args: arguments)
+                return result.isNil ? nil : result
+            } catch {
+                preconditionFailure("Ruby type was T_DATA but not a method reference. Couldn't call method.")
+            }
+        default:
+            return nil
+        }
+    }
+}
+
 // MARK: - Array<RbObject> helper
 
 extension Array where Element == RbObject {

Tests/RubyGatewayTests/TestDynamic.swift

@@ -9,64 +9,64 @@ import XCTest
 import RubyGateway
 
 // Tests for dynamic member function
-//class skip_TestDynamic: XCTestCase {
-//
-//    /// Getter
-//    func testDynamicMemberLookupRead() {
-//        doErrorFree {
-//            try Ruby.require(filename: Helpers.fixturePath("methods.rb"))
-//
-//            guard let obj = RbObject(ofClass: "MethodsTest") else {
-//                XCTFail("Couldn't create object")
-//                return
-//            }
-//
-//            guard let strObj = obj.property else {
-//                XCTFail("Couldn't access member 'property'")
-//                return
-//            }
-//
-//            XCTAssertEqual("Default", String(strObj))
-//
-//            if let mysterious = obj.not_a_member {
-//                XCTFail("Accessed not_a_member: \(mysterious)")
-//                return
-//            }
-//        }
-//    }
-//
-//    /// Write
-//    func testDynamicMemberLookupWrite() {
-//        doErrorFree {
-//            try Ruby.require(filename: Helpers.fixturePath("methods.rb"))
-//
-//            guard let obj = RbObject(ofClass: "MethodsTest") else {
-//                XCTFail("Couldn't create object")
-//                return
-//            }
-//
-//            let newValue = "Changed it!"
-//            obj.property = RbObject(newValue)
-//
-//            guard let strObj = obj.property else {
-//                XCTFail("Couldn't access member 'property'")
-//                return
-//            }
-//
-//            XCTAssertEqual(newValue, String(strObj))
-//
-//            RbError.history.clear()
-//            obj.bad_property = RbObject(23)
-//            XCTAssertNotNil(RbError.history.mostRecent)
-//
-//            RbError.history.clear()
-//            obj.property = nil
-//            XCTAssertEqual(.nilObject, obj.property)
-//        }
-//    }
-//
-//    static var allTests = [
-//        ("testDynamicMemberLookupRead", testDynamicMemberLookupRead),
-//        ("testDynamicMemberLookupWrite", testDynamicMemberLookupWrite),
-//    ]
-//}
+class TestDynamic: XCTestCase {
+
+    /// Getter
+    func testDynamicMemberLookupRead() {
+        doErrorFree {
+            try Ruby.require(filename: Helpers.fixturePath("methods.rb"))
+
+            guard let obj = RbObject(ofClass: "MethodsTest") else {
+                XCTFail("Couldn't create object")
+                return
+            }
+
+            guard let strObj = obj.property else {
+                XCTFail("Couldn't access member 'property'")
+                return
+            }
+
+            XCTAssertEqual("Default", String(strObj))
+
+            if let mysterious = obj.not_a_member {
+                XCTFail("Accessed not_a_member: \(mysterious)")
+                return
+            }
+        }
+    }
+
+    /// Write
+    func testDynamicMemberLookupWrite() {
+        doErrorFree {
+            try Ruby.require(filename: Helpers.fixturePath("methods.rb"))
+
+            guard let obj = RbObject(ofClass: "MethodsTest") else {
+                XCTFail("Couldn't create object")
+                return
+            }
+
+            let newValue = "Changed it!"
+            obj.property = RbObject(newValue)
+
+            guard let strObj = obj.property else {
+                XCTFail("Couldn't access member 'property'")
+                return
+            }
+
+            XCTAssertEqual(newValue, String(strObj))
+
+            RbError.history.clear()
+            obj.bad_property = RbObject(23)
+            XCTAssertNotNil(RbError.history.mostRecent)
+
+            RbError.history.clear()
+            obj.property = nil
+            XCTAssertEqual(.nilObject, obj.property)
+        }
+    }
+
+    static var allTests = [
+        ("testDynamicMemberLookupRead", testDynamicMemberLookupRead),
+        ("testDynamicMemberLookupWrite", testDynamicMemberLookupWrite),
+    ]
+}