diff --git a/Sources/Extractor.swift b/Sources/Extractor.swift
index 45f0005..ea92ed8 100644
--- a/Sources/Extractor.swift
+++ b/Sources/Extractor.swift
@@ -72,17 +72,15 @@ public struct Extractor {
     }
 
     /// - Throws: DecodeError or an arbitrary ErrorType
+    @available(*, unavailable, renamed: "value(_:)")
     public func array<T: Decodable>(_ keyPath: KeyPath) throws -> [T] {
-        guard let array: [T] = try arrayOptional(keyPath) else {
-            throw DecodeError.missingKeyPath(keyPath)
-        }
-
-        return array
+        fatalError()
     }
 
     /// - Throws: DecodeError or an arbitrary ErrorType
+    @available(*, unavailable, renamed: "valueOptional(_:)")
     public func arrayOptional<T: Decodable>(_ keyPath: KeyPath) throws -> [T]? {
-        return try _rawValue(keyPath).map([T].decode)
+        fatalError()
     }
 
     /// - Throws: DecodeError or an arbitrary ErrorType
diff --git a/Sources/Operators.swift b/Sources/Operators.swift
index 0e31f47..52292d1 100644
--- a/Sources/Operators.swift
+++ b/Sources/Operators.swift
@@ -26,13 +26,13 @@ public func <|? <T: Decodable>(e: Extractor, keyPath: KeyPath) throws -> T? {
 /// - Throws: DecodeError or an arbitrary ErrorType
 @available(*, unavailable, renamed: "<|")
 public func <|| <T: Decodable>(e: Extractor, keyPath: KeyPath) throws -> [T] {
-    return try e.array(keyPath)
+    fatalError()
 }
 
 /// - Throws: DecodeError or an arbitrary ErrorType
 @available(*, unavailable, renamed: "<|?")
 public func <||? <T: Decodable>(e: Extractor, keyPath: KeyPath) throws -> [T]? {
-    return try e.arrayOptional(keyPath)
+    fatalError()
 }
 
 /// - Throws: DecodeError or an arbitrary ErrorType
diff --git a/Sources/StandardLib.swift b/Sources/StandardLib.swift
index dd33a0c..f6aee04 100644
--- a/Sources/StandardLib.swift
+++ b/Sources/StandardLib.swift
@@ -74,12 +74,12 @@ extension Array: Decodable where Element: Decodable {
 
     /// - Throws: DecodeError or an arbitrary ErrorType
     public static func decode(from data: Data, rootKeyPath: KeyPath) throws -> [Element] {
-        return try Extractor(from: data).array(rootKeyPath)
+        return try Extractor(from: data).value(rootKeyPath)
     }
 
     /// - Throws: DecodeError or an arbitrary ErrorType
     public static func decode(_ JSON: Any, rootKeyPath: KeyPath) throws -> [Element] {
-        return try Extractor(JSON).array(rootKeyPath)
+        return try Extractor(JSON).value(rootKeyPath)
     }
 }
 
diff --git a/Tests/HimotokiTests/TransformerTest.swift b/Tests/HimotokiTests/TransformerTest.swift
index 4a3b30a..a2b3347 100644
--- a/Tests/HimotokiTests/TransformerTest.swift
+++ b/Tests/HimotokiTests/TransformerTest.swift
@@ -32,7 +32,7 @@ private struct URLsByTransformer: Himotoki.Decodable {
         return self.init(
             value: try Transformer { try toURL($0) }.apply(e <| "value"),
             valueOptional: try URLTransformer.apply(e.valueOptional("valueOptional")),
-            array: try URLTransformer.apply(e.array("array")),
+            array: try URLTransformer.apply(e.value("array")),
             arrayOptional: try URLTransformer.apply(e <|? "arrayOptional"),
             dictionary: try URLTransformer.apply(e <| "dictionary"),
             dictionaryOptional: try URLTransformer.apply(e.dictionaryOptional("dictionaryOptional"))