Packages

•  package root

  The Scala compiler and reflection APIs.

  The Scala compiler and reflection APIs.

  Definition Classes

  root

•  package scala

  Definition Classes

  root

•  package tools

  Definition Classes

  scala

•  package nsc

  Definition Classes

  tools

•  package interpreter

  The main REPL related classes and values are as follows.

  The main REPL related classes and values are as follows. In addition to standard compiler classes Global and Settings, there are:

  History: an interface for session history. Completion: an interface for tab completion. ILoop (formerly InterpreterLoop): The umbrella class for a session. IMain (formerly Interpreter): Handles the evolving state of the session and handles submitting code to the compiler and handling the output. InteractiveReader: how ILoop obtains input. History: an interface for session history. Completion: an interface for tab completion. Power: a repository for more advanced/experimental features.

  ILoop contains { in: InteractiveReader, intp: IMain, settings: Settings, power: Power } InteractiveReader contains { history: History, completion: Completion } IMain contains { global: Global }

  Definition Classes

  nsc

•  class IMain extends Imports with PresentationCompilation with Closeable

  An interpreter for Scala code.

  An interpreter for Scala code.

  The main public entry points are compile(), interpret(), and bind(). The compile() method loads a complete Scala file. The interpret() method executes one line of Scala code at the request of the user. The bind() method binds an object to a variable that can then be used by later interpreted code.

  The overall approach is based on compiling the requested code and then using a Java classloader and Java reflection to run the code and access its results.

  In more detail, a single compiler instance is used to accumulate all successfully compiled or interpreted Scala code. To "interpret" a line of code, the compiler generates a fresh object that includes the line of code and which has public member(s) to export all variables defined by that code. To extract the result of an interpreted line to show the user, a second "result object" is created which imports the variables exported by the above object and then exports members called "$eval" and "$print". To accommodate user expressions that read from variables or methods defined in previous statements, "import" statements are used.

  This interpreter shares the strengths and weaknesses of using the full compiler-to-Java. The main strength is that interpreted code behaves exactly as does compiled code, including running at full speed. The main weakness is that redefining classes and methods is not handled properly, because rebinding at the Java level is technically difficult.

  Definition Classes

  interpreter

•  object parse

  Parse a line into and return parsing result (error, incomplete or success with list of trees)

  Parse a line into and return parsing result (error, incomplete or success with list of trees)

  Definition Classes

  IMain

• Error
• Incomplete
• Result
• Success

scala.tools.nsc.interpreter.IMain.parse

Result 