5 files changed, 120 insertions, 0 deletions
diff --git a/src/main/scala/myapp/application.scala b/src/main/scala/myapp/application.scala
new file mode 100644
index 0000000..24cda2a
--- /dev/null
+++ b/src/main/scala/myapp/application.scala
@@ -0,0 +1,13 @@
+package myapp.application
+
+import myapp.logger.Logger
+import myapp.database.Database
+
+class MyApp (logger: Logger, dbh: Database) {
+  def run {
+    logger.log("starting")
+    logger.log("got a dbh: " + dbh)
+    logger.log(dbh.query("foo"))
+    logger.log("ending")
+  }
+}
diff --git a/src/main/scala/myapp/cake/container.scala b/src/main/scala/myapp/cake/container.scala
new file mode 100644
index 0000000..7c40880
--- /dev/null
+++ b/src/main/scala/myapp/cake/container.scala
@@ -0,0 +1,48 @@
+package myapp.cake.container
+
+import myapp.cake.services
+import myapp.logger.FileLogger
+import myapp.database.DBI
+import myapp.application.MyApp
+
+trait HasLogger extends services.HasLogger {
+  type LoggerType = Logger
+
+  class Logger(
+    logFileName: String
+  ) extends FileLogger(logFileName) with LoggerService
+}
+
+trait HasDatabase extends services.HasDatabase {
+  type DatabaseType = Database
+
+  class Database protected (
+    dsn:      String,
+    username: String,
+    password: String
+  ) extends DBI(dsn, username, password) with DatabaseService
+
+  object Database {
+    def connect(dsn: String, username: String, password: String) =
+      new Database(dsn, username, password)
+  }
+}
+
+trait HasApplication extends services.HasApplication {
+  this: HasLogger with HasDatabase =>
+
+  type ApplicationType = Application
+
+  class Application extends MyApp(logger, database) with ApplicationService
+}
+
+class Container (
+  logFileName: String = "out.log",
+  dsn:         String = "dbi:mysql:myapp",
+  username:    String = "doy",
+  password:    String = "blah"
+) extends HasApplication with HasLogger with HasDatabase {
+  lazy val application = new Application
+  lazy val logger      = new Logger(logFileName)
+  lazy val database    = Database.connect(dsn, username, password)
+}
diff --git a/src/main/scala/myapp/cake/services.scala b/src/main/scala/myapp/cake/services.scala
new file mode 100644
index 0000000..99be3d5
--- /dev/null
+++ b/src/main/scala/myapp/cake/services.scala
@@ -0,0 +1,30 @@
+package myapp.cake.services
+
+import myapp.database.Database
+import myapp.logger.Logger
+
+trait HasApplication {
+  type ApplicationType
+
+  val application: ApplicationType with ApplicationService
+
+  trait ApplicationService {
+    def run (): Unit
+  }
+}
+
+trait HasDatabase {
+  type DatabaseType
+
+  val database: DatabaseType with DatabaseService
+
+  trait DatabaseService extends Database
+}
+
+trait HasLogger {
+  type LoggerType
+
+  val logger: LoggerType with LoggerService
+
+  trait LoggerService extends Logger
+}
diff --git a/src/main/scala/myapp/database.scala b/src/main/scala/myapp/database.scala
new file mode 100644
index 0000000..9a321c2
--- /dev/null
+++ b/src/main/scala/myapp/database.scala
@@ -0,0 +1,19 @@
+package myapp.database
+
+trait Database {
+  def query (search: String): String
+}
+
+class DBI protected (
+  dsn:      String,
+  username: String,
+  password: String
+) extends Database {
+  def query (search: String): String = "found " + search
+  override def toString = List(dsn, username, password).mkString(", ")
+}
+
+object DBI {
+  def connect (dsn: String, username: String, password: String) =
+    new DBI(dsn, username, password)
+}
diff --git a/src/main/scala/myapp/logger.scala b/src/main/scala/myapp/logger.scala
new file mode 100644
index 0000000..8e985dc
--- /dev/null
+++ b/src/main/scala/myapp/logger.scala
@@ -0,0 +1,10 @@
+package myapp.logger
+
+trait Logger {
+  def log (msg: String): Unit
+}
+
+class FileLogger (logFileName: String) extends Logger {
+  def log (msg: String): Unit =
+    println("writing " + msg + " to " + logFileName)
+}