theory Scala

imports Base

begin

chapter {* Isabelle/Scala development tools *}

text {* Isabelle/ML and Isabelle/Scala are the two main language

environments for Isabelle tool implementations.  There are some basic

command-line tools to work with the underlying Java Virtual Machine,

the Scala toplevel and compiler.  Note that Isabelle/jEdit

\cite{isabelle-jedit} provides a Scala Console for interactive

experimentation within the running application. *}

section {* Java Runtime Environment within Isabelle \label{sec:tool-java} *}

text {* The @{tool_def java} tool is a direct wrapper for the Java

  Runtime Environment, within the regular Isabelle settings

  environment (\secref{sec:settings}).  The command line arguments are

  that of the underlying Java version.  It is run in @{verbatim

  "-server"} mode if possible, to improve performance (at the cost of

  extra startup time).

  The @{verbatim java} executable is the one within @{setting

  ISABELLE_JDK_HOME}, according to the standard directory layout for

  official JDK distributions.  The class loader is augmented such that

  the name space of @{verbatim "Isabelle/Pure.jar"} is available,

  which is the main Isabelle/Scala module.

  For example, the following command-line invokes the main method of

  class @{verbatim isabelle.GUI_Setup}, which opens a windows with

  some diagnostic information about the Isabelle environment:

\begin{alltt}

  isabelle java isabelle.GUI_Setup

\end{alltt}

*}

section {* Scala toplevel \label{sec:tool-scala} *}

text {* The @{tool_def scala} tool is a direct wrapper for the Scala

  toplevel; see also @{tool java} above.  The command line arguments

  are that of the underlying Scala version.

  This allows to interact with Isabelle/Scala in TTY mode like this:

\begin{alltt}

  isabelle scala

  scala> isabelle.Isabelle_System.getenv("ISABELLE_HOME")

  scala> val options = isabelle.Options.init()

  scala> options.bool("browser_info")

  scala> options.string("document")

\end{alltt}

*}

section {* Scala compiler \label{sec:tool-scalac} *}

text {* The @{tool_def scalac} tool is a direct wrapper for the Scala

  compiler; see also @{tool scala} above.  The command line arguments

  are that of the underlying Scala version.

  This allows to compile further Scala modules, depending on existing

  Isabelle/Scala functionality.  The resulting class or jar files can

  be added to the Java classpath using the @{verbatim classpath} Bash

  function that is provided by the Isabelle process environment.  Thus

  add-on components can register themselves in a modular manner, see

  also \secref{sec:components}.

  Note that jEdit \cite{isabelle-jedit} has its own mechanisms for

  adding plugin components, which needs special attention since

  it overrides the standard Java class loader.  *}

section {* Scala script wrapper *}

text {* The executable @{executable

  "$ISABELLE_HOME/bin/isabelle_scala_script"} allows to run

  Isabelle/Scala source files stand-alone programs, by using a

  suitable ``hash-bang'' line and executable file permissions.

  The subsequent example assumes that the main Isabelle binaries have

  been installed in some directory that is included in @{setting PATH}

  (see also @{tool "install"}):

\begin{alltt}

#!/usr/bin/env isabelle_scala_script

val options = isabelle.Options.init()

Console.println("browser_info = " + options.bool("browser_info"))

Console.println("document = " + options.string("document"))

\end{alltt}

  Alternatively the full @{file

  "$ISABELLE_HOME/bin/isabelle_scala_script"} may be specified in

  expanded form.  *}

end