diff --git a/.swiftlint.yml b/.swiftlint.yml
index b5e53d56..34bb253b 100644
--- a/.swiftlint.yml
+++ b/.swiftlint.yml
@@ -38,5 +38,6 @@ line_length:
   ignores_comments: true
 
 file_length:
-  warning: 900
-  error: 900
+  warning: 500
+  error: 500
+  ignore_comment_only_lines: true
diff --git a/SQLite.xcodeproj/project.pbxproj b/SQLite.xcodeproj/project.pbxproj
index b30c18d2..5bb52f4e 100644
--- a/SQLite.xcodeproj/project.pbxproj
+++ b/SQLite.xcodeproj/project.pbxproj
@@ -50,6 +50,7 @@
 		03A65E971C6BB3210062603F /* libsqlite3.tbd in Frameworks */ = {isa = PBXBuildFile; fileRef = 03A65E961C6BB3210062603F /* libsqlite3.tbd */; };
 		19A17073552293CA063BEA66 /* Result.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A17E723300E5ED3771DCB5 /* Result.swift */; };
 		19A1709C3E7A406E62293B2A /* Fixtures.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A17B93B48B5560E6E51791 /* Fixtures.swift */; };
+		19A170ACC97B19730FB7BA4D /* Connection+Aggregation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A175A9CB446640AE6F2200 /* Connection+Aggregation.swift */; };
 		19A17152E32A9585831E3FE0 /* DateAndTimeFunctions.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A17BA55DABB480F9020C8A /* DateAndTimeFunctions.swift */; };
 		19A1717B10CC941ACB5533D6 /* FTS5.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A1730E4390C775C25677D1 /* FTS5.swift */; };
 		19A171967CC511C4F6F773C9 /* RowTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A175C1F9CB3BBAB8FCEC7B /* RowTests.swift */; };
@@ -67,6 +68,7 @@
 		19A174D78559CD30679BCCCB /* FTS5Tests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A1721B8984686B9963B45D /* FTS5Tests.swift */; };
 		19A1750CEE9B05267995CF3D /* FTS5.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A1730E4390C775C25677D1 /* FTS5.swift */; };
 		19A175DFF47B84757E547C62 /* fixtures in Resources */ = {isa = PBXBuildFile; fileRef = 19A17E2695737FAB5D6086E3 /* fixtures */; };
+		19A176376CB6A94759F7980A /* Connection+Aggregation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A175A9CB446640AE6F2200 /* Connection+Aggregation.swift */; };
 		19A176406BDE9D9C80CC9FA3 /* QueryIntegrationTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A17BA6B4E282C1315A115C /* QueryIntegrationTests.swift */; };
 		19A1769C1F3A7542BECF50FF /* DateAndTimeFunctionTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A1729B75C33F9A0B9A89C1 /* DateAndTimeFunctionTests.swift */; };
 		19A177CC33F2E6A24AF90B02 /* CipherTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A17399EA9E61235D5D77BF /* CipherTests.swift */; };
@@ -75,6 +77,7 @@
 		19A1785195182AF8731A8BDA /* RowTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A175C1F9CB3BBAB8FCEC7B /* RowTests.swift */; };
 		19A1792C0520D4E83C2EB075 /* Errors.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A1710E73A46D5AC721CDA9 /* Errors.swift */; };
 		19A179A0C45377CB09BB358C /* CipherTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A17399EA9E61235D5D77BF /* CipherTests.swift */; };
+		19A179B59450FE7C4811AB8A /* Connection+Aggregation.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A175A9CB446640AE6F2200 /* Connection+Aggregation.swift */; };
 		19A179CCF9671E345E5A9811 /* Cipher.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A178A39ACA9667A62663CC /* Cipher.swift */; };
 		19A179E76EA6207669B60C1B /* Cipher.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A178A39ACA9667A62663CC /* Cipher.swift */; };
 		19A17C4B951CB054EE48AB1C /* CipherTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 19A17399EA9E61235D5D77BF /* CipherTests.swift */; };
@@ -237,6 +240,7 @@
 		19A1729B75C33F9A0B9A89C1 /* DateAndTimeFunctionTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = DateAndTimeFunctionTests.swift; sourceTree = "<group>"; };
 		19A1730E4390C775C25677D1 /* FTS5.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = FTS5.swift; sourceTree = "<group>"; };
 		19A17399EA9E61235D5D77BF /* CipherTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = CipherTests.swift; sourceTree = "<group>"; };
+		19A175A9CB446640AE6F2200 /* Connection+Aggregation.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "Connection+Aggregation.swift"; sourceTree = "<group>"; };
 		19A175C1F9CB3BBAB8FCEC7B /* RowTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = RowTests.swift; sourceTree = "<group>"; };
 		19A178A39ACA9667A62663CC /* Cipher.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Cipher.swift; sourceTree = "<group>"; };
 		19A1794B7972D14330A65BBD /* Linux.md */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = net.daringfireball.markdown; path = Linux.md; sourceTree = "<group>"; };
@@ -462,6 +466,7 @@
 				19A1710E73A46D5AC721CDA9 /* Errors.swift */,
 				02A43A9722738CF100FEC494 /* Backup.swift */,
 				19A17E723300E5ED3771DCB5 /* Result.swift */,
+				19A175A9CB446640AE6F2200 /* Connection+Aggregation.swift */,
 			);
 			path = Core;
 			sourceTree = "<group>";
@@ -850,6 +855,7 @@
 				19A17FF4A10B44D3937C8CAC /* Errors.swift in Sources */,
 				19A1737286A74F3CF7412906 /* DateAndTimeFunctions.swift in Sources */,
 				19A17073552293CA063BEA66 /* Result.swift in Sources */,
+				19A179B59450FE7C4811AB8A /* Connection+Aggregation.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -945,6 +951,7 @@
 				19A1792C0520D4E83C2EB075 /* Errors.swift in Sources */,
 				19A17E29278A12BC4F542506 /* DateAndTimeFunctions.swift in Sources */,
 				19A173EFEF0B3BD0B3ED406C /* Result.swift in Sources */,
+				19A176376CB6A94759F7980A /* Connection+Aggregation.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -1008,6 +1015,7 @@
 				19A17490543609FCED53CACC /* Errors.swift in Sources */,
 				19A17152E32A9585831E3FE0 /* DateAndTimeFunctions.swift in Sources */,
 				19A17F1B3F0A3C96B5ED6D64 /* Result.swift in Sources */,
+				19A170ACC97B19730FB7BA4D /* Connection+Aggregation.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
diff --git a/Sources/SQLite/Core/Connection+Aggregation.swift b/Sources/SQLite/Core/Connection+Aggregation.swift
new file mode 100644
index 00000000..106f292c
--- /dev/null
+++ b/Sources/SQLite/Core/Connection+Aggregation.swift
@@ -0,0 +1,155 @@
+import Foundation
+#if SQLITE_SWIFT_STANDALONE
+import sqlite3
+#elseif SQLITE_SWIFT_SQLCIPHER
+import SQLCipher
+#elseif os(Linux)
+import CSQLite
+#else
+import SQLite3
+#endif
+
+extension Connection {
+    private typealias Aggregate = @convention(block) (Int, Context, Int32, Argv) -> Void
+
+    /// Creates or redefines a custom SQL aggregate.
+    ///
+    /// - Parameters:
+    ///
+    ///   - aggregate: The name of the aggregate to create or redefine.
+    ///
+    ///   - argumentCount: The number of arguments that the aggregate takes. If
+    ///     `nil`, the aggregate may take any number of arguments.
+    ///
+    ///     Default: `nil`
+    ///
+    ///   - deterministic: Whether or not the aggregate is deterministic (_i.e._
+    ///     the aggregate always returns the same result for a given input).
+    ///
+    ///     Default: `false`
+    ///
+    ///   - step: A block of code to run for each row of an aggregation group.
+    ///     The block is called with an array of raw SQL values mapped to the
+    ///     aggregate’s parameters, and an UnsafeMutablePointer to a state
+    ///     variable.
+    ///
+    ///   - final: A block of code to run after each row of an aggregation group
+    ///     is processed. The block is called with an UnsafeMutablePointer to a
+    ///     state variable, and should return a raw SQL value (or nil).
+    ///
+    ///   - state: A block of code to run to produce a fresh state variable for
+    ///     each aggregation group. The block should return an
+    ///     UnsafeMutablePointer to the fresh state variable.
+    public func createAggregation<T>(
+            _ functionName: String,
+            argumentCount: UInt? = nil,
+            deterministic: Bool = false,
+            step: @escaping ([Binding?], UnsafeMutablePointer<T>) -> Void,
+            final: @escaping (UnsafeMutablePointer<T>) -> Binding?,
+            state: @escaping () -> UnsafeMutablePointer<T>) {
+
+        let argc = argumentCount.map { Int($0) } ?? -1
+        let box: Aggregate = { (stepFlag: Int, context: Context, argc: Int32, argv: Argv) in
+            let nBytes = Int32(MemoryLayout<UnsafeMutablePointer<Int64>>.size)
+            guard let aggregateContext = sqlite3_aggregate_context(context, nBytes) else {
+                fatalError("Could not get aggregate context")
+            }
+            let mutablePointer = aggregateContext.assumingMemoryBound(to: UnsafeMutableRawPointer.self)
+            if stepFlag > 0 {
+                let arguments = argv.getBindings(argc: argc)
+                if aggregateContext.assumingMemoryBound(to: Int64.self).pointee == 0 {
+                    mutablePointer.pointee = UnsafeMutableRawPointer(mutating: state())
+                }
+                step(arguments, mutablePointer.pointee.assumingMemoryBound(to: T.self))
+            } else {
+                let result = final(mutablePointer.pointee.assumingMemoryBound(to: T.self))
+                context.set(result: result)
+            }
+        }
+
+        func xStep(context: Context, argc: Int32, value: Argv) {
+            unsafeBitCast(sqlite3_user_data(context), to: Aggregate.self)(1, context, argc, value)
+        }
+
+        func xFinal(context: Context) {
+            unsafeBitCast(sqlite3_user_data(context), to: Aggregate.self)(0, context, 0, nil)
+        }
+
+        let flags = SQLITE_UTF8 | (deterministic ? SQLITE_DETERMINISTIC : 0)
+        let resultCode = sqlite3_create_function_v2(
+            handle,
+            functionName,
+            Int32(argc),
+            flags,
+            /* pApp */ unsafeBitCast(box, to: UnsafeMutableRawPointer.self),
+            /* xFunc */ nil, xStep, xFinal, /* xDestroy */ nil
+        )
+        if let result = Result(errorCode: resultCode, connection: self) {
+            fatalError("Error creating function: \(result)")
+        }
+        register(functionName, argc: argc, value: box)
+    }
+
+    func createAggregation<T: AnyObject>(
+            _ aggregate: String,
+            argumentCount: UInt? = nil,
+            deterministic: Bool = false,
+            initialValue: T,
+            reduce: @escaping (T, [Binding?]) -> T,
+            result: @escaping (T) -> Binding?
+    ) {
+        let step: ([Binding?], UnsafeMutablePointer<UnsafeMutableRawPointer>) -> Void = { (bindings, ptr) in
+            let pointer = ptr.pointee.assumingMemoryBound(to: T.self)
+            let current = Unmanaged<T>.fromOpaque(pointer).takeRetainedValue()
+            let next = reduce(current, bindings)
+            ptr.pointee = Unmanaged.passRetained(next).toOpaque()
+        }
+
+        let final: (UnsafeMutablePointer<UnsafeMutableRawPointer>) -> Binding? = { ptr in
+            let pointer = ptr.pointee.assumingMemoryBound(to: T.self)
+            let obj = Unmanaged<T>.fromOpaque(pointer).takeRetainedValue()
+            let value = result(obj)
+            ptr.deallocate()
+            return value
+        }
+
+        let state: () -> UnsafeMutablePointer<UnsafeMutableRawPointer> = {
+            let pointer = UnsafeMutablePointer<UnsafeMutableRawPointer>.allocate(capacity: 1)
+            pointer.pointee = Unmanaged.passRetained(initialValue).toOpaque()
+            return pointer
+        }
+
+        createAggregation(aggregate, step: step, final: final, state: state)
+    }
+
+    func createAggregation<T>(
+            _ aggregate: String,
+            argumentCount: UInt? = nil,
+            deterministic: Bool = false,
+            initialValue: T,
+            reduce: @escaping (T, [Binding?]) -> T,
+            result: @escaping (T) -> Binding?
+    ) {
+
+        let step: ([Binding?], UnsafeMutablePointer<T>) -> Void = { (bindings, pointer) in
+            let current = pointer.pointee
+            let next = reduce(current, bindings)
+            pointer.pointee = next
+        }
+
+        let final: (UnsafeMutablePointer<T>) -> Binding? = { pointer in
+            let value = result(pointer.pointee)
+            pointer.deallocate()
+            return value
+        }
+
+        let state: () -> UnsafeMutablePointer<T> = {
+            let pointer = UnsafeMutablePointer<T>.allocate(capacity: 1)
+            pointer.initialize(to: initialValue)
+            return pointer
+        }
+
+        createAggregation(aggregate, step: step, final: final, state: state)
+    }
+
+}
diff --git a/Sources/SQLite/Core/Connection.swift b/Sources/SQLite/Core/Connection.swift
index a9012462..6b5481e3 100644
--- a/Sources/SQLite/Core/Connection.swift
+++ b/Sources/SQLite/Core/Connection.swift
@@ -35,7 +35,6 @@ import SQLite3
 #endif
 
 /// A connection to SQLite.
-// swiftlint:disable:next type_body_length
 public final class Connection {
 
     /// The location of a SQLite database.
@@ -586,182 +585,42 @@ public final class Connection {
     ///   - block: A block of code to run when the function is called. The block
     ///     is called with an array of raw SQL values mapped to the function’s
     ///     parameters and should return a raw SQL value (or nil).
-    // swiftlint:disable:next cyclomatic_complexity
-    public func createFunction(_ function: String, argumentCount: UInt? = nil, deterministic: Bool = false,
+    public func createFunction(_ functionName: String,
+                               argumentCount: UInt? = nil,
+                               deterministic: Bool = false,
                                _ block: @escaping (_ args: [Binding?]) -> Binding?) {
         let argc = argumentCount.map { Int($0) } ?? -1
-        let box: Function = { context, argc, argv in
-            let arguments: [Binding?] = (0..<Int(argc)).map { idx in
-                let value = argv![idx]
-                switch sqlite3_value_type(value) {
-                case SQLITE_BLOB:
-                    return Blob(bytes: sqlite3_value_blob(value), length: Int(sqlite3_value_bytes(value)))
-                case SQLITE_FLOAT:
-                    return sqlite3_value_double(value)
-                case SQLITE_INTEGER:
-                    return sqlite3_value_int64(value)
-                case SQLITE_NULL:
-                    return nil
-                case SQLITE_TEXT:
-                    return String(cString: UnsafePointer(sqlite3_value_text(value)))
-                case let type:
-                    fatalError("unsupported value type: \(type)")
-                }
-            }
-            let result = block(arguments)
-            if let result = result as? Blob {
-                sqlite3_result_blob(context, result.bytes, Int32(result.bytes.count), nil)
-            } else if let result = result as? Double {
-                sqlite3_result_double(context, result)
-            } else if let result = result as? Int64 {
-                sqlite3_result_int64(context, result)
-            } else if let result = result as? String {
-                sqlite3_result_text(context, result, Int32(result.lengthOfBytes(using: .utf8)), SQLITE_TRANSIENT)
-            } else if result == nil {
-                sqlite3_result_null(context)
-            } else {
-                fatalError("unsupported result type: \(String(describing: result))")
-            }
+        let box: Function = { (context: Context, argc, argv: Argv) in
+            context.set(result: block(argv.getBindings(argc: argc)))
         }
-        var flags = SQLITE_UTF8
-        #if !os(Linux)
-        if deterministic {
-            flags |= SQLITE_DETERMINISTIC
-        }
-        #endif
-        let resultCode = sqlite3_create_function_v2(handle,
-                                                    function,
-                                                    Int32(argc),
-                                                    flags,
-                                                    unsafeBitCast(box, to: UnsafeMutableRawPointer.self), { context, argc, value in
-            let function = unsafeBitCast(sqlite3_user_data(context), to: Function.self)
-            function(context, argc, value)
-        }, nil, nil, nil)
-
-        if let result = Result(errorCode: resultCode, connection: self, statement: nil) {
-            fatalError("Error creating function: \(result)")
+        func xFunc(context: Context, argc: Int32, value: Argv) {
+            unsafeBitCast(sqlite3_user_data(context), to: Function.self)(context, argc, value)
         }
+        let flags = SQLITE_UTF8 | (deterministic ? SQLITE_DETERMINISTIC : 0)
+        let resultCode = sqlite3_create_function_v2(
+            handle,
+            functionName,
+            Int32(argc),
+            flags,
+            /* pApp */ unsafeBitCast(box, to: UnsafeMutableRawPointer.self),
+            xFunc, /*xStep*/ nil, /*xFinal*/ nil, /*xDestroy*/ nil
+        )
 
-        if functions[function] == nil {
-            functions[function] = [:] // fails on Linux, https://github.com/stephencelis/SQLite.swift/issues/1071
+        if let result = Result(errorCode: resultCode, connection: self) {
+            fatalError("Error creating function: \(result)")
         }
-        functions[function]?[argc] = box
+        register(functionName, argc: argc, value: box)
     }
 
-    /// Creates or redefines a custom SQL aggregate.
-    ///
-    /// - Parameters:
-    ///
-    ///   - aggregate: The name of the aggregate to create or redefine.
-    ///
-    ///   - argumentCount: The number of arguments that the aggregate takes. If
-    ///     `nil`, the aggregate may take any number of arguments.
-    ///
-    ///     Default: `nil`
-    ///
-    ///   - deterministic: Whether or not the aggregate is deterministic (_i.e._
-    ///     the aggregate always returns the same result for a given input).
-    ///
-    ///     Default: `false`
-    ///
-    ///   - step: A block of code to run for each row of an aggregation group.
-    ///     The block is called with an array of raw SQL values mapped to the
-    ///     aggregate’s parameters, and an UnsafeMutablePointer to a state
-    ///     variable.
-    ///
-    ///   - final: A block of code to run after each row of an aggregation group
-    ///     is processed. The block is called with an UnsafeMutablePointer to a
-    ///     state variable, and should return a raw SQL value (or nil).
-    ///
-    ///   - state: A block of code to run to produce a fresh state variable for
-    ///     each aggregation group. The block should return an
-    ///     UnsafeMutablePointer to the fresh state variable.
-    // swiftlint:disable:next cyclomatic_complexity
-    public func createAggregation<T>(
-        _ aggregate: String,
-        argumentCount: UInt? = nil,
-        deterministic: Bool = false,
-        step: @escaping ([Binding?], UnsafeMutablePointer<T>) -> Void,
-        final: @escaping (UnsafeMutablePointer<T>) -> Binding?,
-        state: @escaping () -> UnsafeMutablePointer<T>) {
-
-        let argc = argumentCount.map { Int($0) } ?? -1
-        let box: Aggregate = { (stepFlag: Int, context: OpaquePointer?, argc: Int32, argv: UnsafeMutablePointer<OpaquePointer?>?) in
-            let ptr = sqlite3_aggregate_context(context, 64)! // needs to be at least as large as uintptr_t; better way to do this?
-            let mutablePointer = ptr.assumingMemoryBound(to: UnsafeMutableRawPointer.self)
-            if stepFlag > 0 {
-                let arguments: [Binding?] = (0..<Int(argc)).map { idx in
-                    let value = argv![idx]
-                    switch sqlite3_value_type(value) {
-                    case SQLITE_BLOB:
-                        return Blob(bytes: sqlite3_value_blob(value), length: Int(sqlite3_value_bytes(value)))
-                    case SQLITE_FLOAT:
-                        return sqlite3_value_double(value)
-                    case SQLITE_INTEGER:
-                        return sqlite3_value_int64(value)
-                    case SQLITE_NULL:
-                        return nil
-                    case SQLITE_TEXT:
-                        return String(cString: UnsafePointer(sqlite3_value_text(value)))
-                    case let type:
-                        fatalError("unsupported value type: \(type)")
-                    }
-                }
-
-                if ptr.assumingMemoryBound(to: Int64.self).pointee == 0 {
-                    let value = state()
-                    mutablePointer.pointee = UnsafeMutableRawPointer(mutating: value)
-                }
-                step(arguments, mutablePointer.pointee.assumingMemoryBound(to: T.self))
-            } else {
-                let result = final(mutablePointer.pointee.assumingMemoryBound(to: T.self))
-                if let result = result as? Blob {
-                    sqlite3_result_blob(context, result.bytes, Int32(result.bytes.count), nil)
-                } else if let result = result as? Double {
-                    sqlite3_result_double(context, result)
-                } else if let result = result as? Int64 {
-                    sqlite3_result_int64(context, result)
-                } else if let result = result as? String {
-                    sqlite3_result_text(context, result, Int32(result.count), SQLITE_TRANSIENT)
-                } else if result == nil {
-                    sqlite3_result_null(context)
-                } else {
-                    fatalError("unsupported result type: \(String(describing: result))")
-                }
-            }
-        }
-
-        var flags = SQLITE_UTF8
-        #if !os(Linux)
-        if deterministic {
-            flags |= SQLITE_DETERMINISTIC
+    func register(_ functionName: String, argc: Int, value: Any) {
+        if functions[functionName] == nil {
+            functions[functionName] = [:] // fails on Linux, https://github.com/stephencelis/SQLite.swift/issues/1071
         }
-        #endif
-
-        sqlite3_create_function_v2(
-            handle,
-            aggregate,
-            Int32(argc),
-            flags,
-            unsafeBitCast(box, to: UnsafeMutableRawPointer.self),
-            nil,
-            { context, argc, value in
-                let function = unsafeBitCast(sqlite3_user_data(context), to: Aggregate.self)
-                function(1, context, argc, value)
-        }, { context in
-                let function = unsafeBitCast(sqlite3_user_data(context), to: Aggregate.self)
-                function(0, context, 0, nil)
-        },
-            nil
-        )
-        if aggregations[aggregate] == nil { self.aggregations[aggregate] = [:] }
-        aggregations[aggregate]?[argc] = box
+        functions[functionName]?[argc] = value
     }
 
-    fileprivate typealias Aggregate = @convention(block) (Int, OpaquePointer?, Int32, UnsafeMutablePointer<OpaquePointer?>?) -> Void
-    fileprivate typealias Function = @convention(block) (OpaquePointer?, Int32, UnsafeMutablePointer<OpaquePointer?>?) -> Void
-    fileprivate var functions = [String: [Int: Function]]()
-    fileprivate var aggregations = [String: [Int: Aggregate]]()
+    fileprivate typealias Function = @convention(block) (Context, Int32, Argv) -> Void
+    fileprivate var functions = [String: [Int: Any]]()
 
     /// Defines a new collating sequence.
     ///
@@ -808,7 +667,6 @@ public final class Connection {
     ///     Default: `.main`.
     ///
     /// - Returns: A new database backup.
-
     public func backup(databaseName: Backup.DatabaseName = .main,
                        usingConnection targetConnection: Connection,
                        andDatabaseName targetDatabaseName: Backup.DatabaseName = .main) throws -> Backup {
@@ -864,3 +722,46 @@ extension Connection.Location: CustomStringConvertible {
     }
 
 }
+
+typealias Context = OpaquePointer?
+extension Context {
+    func set(result: Binding?) {
+        switch result {
+        case let blob as Blob:
+            sqlite3_result_blob(self, blob.bytes, Int32(blob.bytes.count), nil)
+        case let double as Double:
+            sqlite3_result_double(self, double)
+        case let int as Int64:
+            sqlite3_result_int64(self, int)
+        case let string as String:
+            sqlite3_result_text(self, string, Int32(string.lengthOfBytes(using: .utf8)), SQLITE_TRANSIENT)
+        case .none:
+            sqlite3_result_null(self)
+        default:
+            fatalError("unsupported result type: \(String(describing: result))")
+        }
+    }
+}
+
+typealias Argv = UnsafeMutablePointer<OpaquePointer?>?
+extension Argv {
+    func getBindings(argc: Int32) -> [Binding?] {
+        (0..<Int(argc)).map { idx in
+            let value = self![idx]
+            switch sqlite3_value_type(value) {
+            case SQLITE_BLOB:
+                return Blob(bytes: sqlite3_value_blob(value), length: Int(sqlite3_value_bytes(value)))
+            case SQLITE_FLOAT:
+                return sqlite3_value_double(value)
+            case SQLITE_INTEGER:
+                return sqlite3_value_int64(value)
+            case SQLITE_NULL:
+                return nil
+            case SQLITE_TEXT:
+                return String(cString: UnsafePointer(sqlite3_value_text(value)))
+            case let type:
+                fatalError("unsupported value type: \(type)")
+            }
+        }
+    }
+}
diff --git a/Sources/SQLite/Typed/CustomFunctions.swift b/Sources/SQLite/Typed/CustomFunctions.swift
index c38113d1..0eaa8cf3 100644
--- a/Sources/SQLite/Typed/CustomFunctions.swift
+++ b/Sources/SQLite/Typed/CustomFunctions.swift
@@ -159,69 +159,4 @@ public extension Connection {
         }
     }
 
-    // MARK: -
-
-    func createAggregation<T: AnyObject>(
-        _ aggregate: String,
-        argumentCount: UInt? = nil,
-        deterministic: Bool = false,
-        initialValue: T,
-        reduce: @escaping (T, [Binding?]) -> T,
-        result: @escaping (T) -> Binding?
-        ) {
-
-        let step: ([Binding?], UnsafeMutablePointer<UnsafeMutableRawPointer>) -> Void = { (bindings, ptr) in
-            let pointer = ptr.pointee.assumingMemoryBound(to: T.self)
-            let current = Unmanaged<T>.fromOpaque(pointer).takeRetainedValue()
-            let next = reduce(current, bindings)
-            ptr.pointee = Unmanaged.passRetained(next).toOpaque()
-        }
-
-        let final: (UnsafeMutablePointer<UnsafeMutableRawPointer>) -> Binding? = { (ptr) in
-            let pointer = ptr.pointee.assumingMemoryBound(to: T.self)
-            let obj = Unmanaged<T>.fromOpaque(pointer).takeRetainedValue()
-            let value = result(obj)
-            ptr.deallocate()
-            return value
-        }
-
-        let state: () -> UnsafeMutablePointer<UnsafeMutableRawPointer> = {
-            let pointer = UnsafeMutablePointer<UnsafeMutableRawPointer>.allocate(capacity: 1)
-            pointer.pointee = Unmanaged.passRetained(initialValue).toOpaque()
-            return pointer
-        }
-
-        createAggregation(aggregate, step: step, final: final, state: state)
-    }
-
-    func createAggregation<T>(
-        _ aggregate: String,
-        argumentCount: UInt? = nil,
-        deterministic: Bool = false,
-        initialValue: T,
-        reduce: @escaping (T, [Binding?]) -> T,
-        result: @escaping (T) -> Binding?
-        ) {
-
-        let step: ([Binding?], UnsafeMutablePointer<T>) -> Void = { (bindings, pointer) in
-            let current = pointer.pointee
-            let next = reduce(current, bindings)
-            pointer.pointee = next
-        }
-
-        let final: (UnsafeMutablePointer<T>) -> Binding? = { pointer in
-            let value = result(pointer.pointee)
-            pointer.deallocate()
-            return value
-        }
-
-        let state: () -> UnsafeMutablePointer<T> = {
-            let pointer = UnsafeMutablePointer<T>.allocate(capacity: 1)
-            pointer.initialize(to: initialValue)
-            return pointer
-        }
-
-        createAggregation(aggregate, step: step, final: final, state: state)
-    }
-
 }
diff --git a/Sources/SQLite/Typed/Query.swift b/Sources/SQLite/Typed/Query.swift
index 59b24a8d..2d88db63 100644
--- a/Sources/SQLite/Typed/Query.swift
+++ b/Sources/SQLite/Typed/Query.swift
@@ -21,7 +21,6 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 //
-// swiftlint:disable file_length
 import Foundation
 
 public protocol QueryType: Expressible {