--- a/src/Doc/System/Scala.thy Wed May 27 16:04:53 2020 +0200
+++ b/src/Doc/System/Scala.thy Wed May 27 16:05:17 2020 +0200
@@ -4,48 +4,95 @@
imports Base
begin
-chapter \<open>Isabelle/Scala development tools\<close>
+chapter \<open>Isabelle/Scala systems programming\<close>
text \<open>
- 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.
+ Isabelle/ML and Isabelle/Scala are the two main implementation languages of
+ the Isabelle environment:
+
+ \<^item> Isabelle/ML is for \<^emph>\<open>mathematics\<close>, to develop tools within the context
+ of symbolic logic, e.g.\ for constructing proofs or defining
+ domain-specific formal languages. See the \<^emph>\<open>Isabelle/Isar implementation
+ manual\<close> @{cite "isabelle-implementation"} for more details.
+
+ \<^item> Isabelle/Scala is for \<^emph>\<open>physics\<close>, to connect with the world of systems
+ and services, including editors and IDE frameworks.
+
+ There are various ways to access Isabelle/Scala modules and operations:
+
+ \<^item> Isabelle command-line tools (\secref{sec:scala-tools}) run in a separate
+ Java process.
+
+ \<^item> Isabelle/ML antiquotations access Isabelle/Scala functions
+ (\secref{sec:scala-functions}) via the PIDE protocol: execution happens
+ within the running Java process underlying Isabelle/Scala.
+
+ \<^item> The \<^verbatim>\<open>Console/Scala\<close> plugin of Isabelle/jEdit @{cite "isabelle-jedit"}
+ operates on the running Java application, using the Scala
+ read-eval-print-loop (REPL).
+
+ The main Isabelle/Scala functionality is provided by \<^verbatim>\<open>Pure.jar\<close>, but
+ further add-ons are bundled with Isabelle, e.g.\ to access SQLite or
+ PostgreSQL using JDBC (Java Database Connectivity).
+
+ Other components may augment the system environment by providing a suitable
+ \<^path>\<open>etc/settings\<close> shell script in the component directory. Some shell
+ functions are available to help with that:
+
+ \<^item> Function \<^bash_function>\<open>classpath\<close> adds \<^verbatim>\<open>jar\<close> files in Isabelle path
+ notation (POSIX). On Windows, this is converted to native path names
+ before invoking @{tool java} or @{tool scala} (\secref{sec:scala-tools}).
+
+ \<^item> Function \<^bash_function>\<open>isabelle_scala_service\<close> registers global
+ service providers as subclasses of
+ \<^scala_type>\<open>isabelle.Isabelle_System.Service\<close>, using the raw Java name
+ according to @{scala_method (in java.lang.Object) getClass} (it should be
+ enclosed in single quotes to avoid special characters like \<^verbatim>\<open>$\<close> to be
+ interpreted by the shell).
+
+ Particular Isabelle/Scala services require particular subclasses:
+ instances are filtered according to their dynamic type. For example, class
+ \<^scala_type>\<open>isabelle.Isabelle_Scala_Tools\<close> collects Scala command-line
+ tools, and class \<^scala_type>\<open>isabelle.Isabelle_Scala_Functions\<close>
+ collects Scala functions (\secref{sec:scala-functions}).
\<close>
-section \<open>Java Runtime Environment within Isabelle \label{sec:tool-java}\<close>
+section \<open>Command-line tools \label{sec:scala-tools}\<close>
+
+subsection \<open>Java Runtime Environment \label{sec:tool-java}\<close>
text \<open>
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>\<open>-server\<close> mode if possible, to
- improve performance (at the cost of extra startup time).
+ (\secref{sec:settings}) and Isabelle classpath. The command line arguments
+ are that of the bundled Java distribution: see option \<^verbatim>\<open>-help\<close> in
+ particular.
- The \<^verbatim>\<open>java\<close> 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>\<open>Isabelle/Pure.jar\<close> is available, which is the main Isabelle/Scala module.
+ The \<^verbatim>\<open>java\<close> executable is taken from @{setting ISABELLE_JDK_HOME}, according
+ to the standard directory layout for regular distributions of OpenJDK.
+
+ The shell function \<^bash_function>\<open>isabelle_jdk\<close> allows shell scripts to
+ invoke other Java tools robustly (e.g.\ \<^verbatim>\<open>isabelle_jdk jar\<close>), without
+ depending on accidental operating system installations.
\<close>
-section \<open>Scala toplevel \label{sec:tool-scala}\<close>
+subsection \<open>Scala toplevel \label{sec:tool-scala}\<close>
text \<open>
- 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. An alternative is to use the \<^verbatim>\<open>Console/Scala\<close> plugin of Isabelle/jEdit
- @{cite "isabelle-jedit"}.
+ The @{tool_def scala} tool is a direct wrapper for the Scala toplevel,
+ similar to @{tool java} above. The command line arguments are that of the
+ bundled Scala distribution: see option \<^verbatim>\<open>-help\<close> in particular. This allows
+ to interact with Isabelle/Scala interactively.
\<close>
subsubsection \<open>Example\<close>
text \<open>
Explore the Isabelle system environment in Scala:
- @{scala [display]
+ @{verbatim [display, indent = 2] \<open>$ isabelle scala\<close>}
+ @{scala [display, indent = 2]
\<open>import isabelle._
val isabelle_home = Isabelle_System.getenv("ISABELLE_HOME")
@@ -56,35 +103,34 @@
\<close>
-section \<open>Scala compiler \label{sec:tool-scalac}\<close>
+subsection \<open>Scala compiler \label{sec:tool-scalac}\<close>
text \<open>
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.
+ bundled Scala distribution.
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>\<open>classpath\<close> 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}.
+ Isabelle/Scala functionality. The resulting \<^verbatim>\<open>class\<close> or \<^verbatim>\<open>jar\<close> files can be
+ added to the Java classpath using the shell function
+ \<^bash_function>\<open>classpath\<close>. 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.
+ Note that Isabelle/jEdit @{cite "isabelle-jedit"} has its own mechanisms for
+ adding plugin components. This needs special attention, since it overrides
+ the standard Java class loader.
\<close>
-section \<open>Scala script wrapper\<close>
+subsection \<open>Scala script wrapper\<close>
text \<open>
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. For example:
- @{verbatim [display]
-\<open>#!/usr/bin/env isabelle_scala_script
-
-val options = isabelle.Options.init()
+ @{verbatim [display, indent = 2] \<open>#!/usr/bin/env isabelle_scala_script\<close>}
+ @{scala [display, indent = 2]
+\<open>val options = isabelle.Options.init()
Console.println("browser_info = " + options.bool("browser_info"))
Console.println("document = " + options.string("document"))\<close>}
@@ -97,7 +143,7 @@
\<close>
-section \<open>Project setup for common Scala IDEs\<close>
+subsection \<open>Project setup for common Scala IDEs\<close>
text \<open>
The @{tool_def scala_project} tool creates a project configuration for
@@ -116,12 +162,13 @@
IDEA\<^footnote>\<open>\<^url>\<open>https://www.jetbrains.com/idea\<close>\<close>. This allows to explore the
sources with static analysis and other hints in real-time.
- The specified project directory must not exist yet. The generated files
- refer to physical file-system locations, using the path notation of the
- underlying OS platform. Thus the project needs to be recreated whenever the
- Isabelle installation is changed or moved.
+ The specified project directory needs to be fresh. The generated files refer
+ to physical file-system locations, using the path notation of the underlying
+ OS platform. Thus the project needs to be recreated whenever the Isabelle
+ installation is changed or moved.
- \<^medskip> By default, Scala sources are \<^emph>\<open>copied\<close> from the Isabelle distribution and
+ \<^medskip>
+ By default, Scala sources are \<^emph>\<open>copied\<close> from the Isabelle distribution and
editing them within the IDE has no permanent effect.
Option \<^verbatim>\<open>-L\<close> produces \<^emph>\<open>symlinks\<close> to the original files: this allows to
@@ -130,4 +177,161 @@
command-line.
\<close>
+
+section \<open>Registered Isabelle/Scala functions \label{sec:scala-functions}\<close>
+
+subsection \<open>Defining functions in Isabelle/Scala\<close>
+
+text \<open>
+ A Scala functions of type \<^scala_type>\<open>String => String\<close> may be wrapped as
+ \<^scala_type>\<open>isabelle.Scala.Fun\<close> and collected via an instance of the
+ class \<^scala_type>\<open>isabelle.Isabelle_Scala_Functions\<close>. A system component
+ can then register that class via \<^bash_function>\<open>isabelle_scala_service\<close>
+ in \<^path>\<open>etc/settings\<close> (\secref{sec:components}). An example is the
+ predefined collection of \<^scala_type>\<open>isabelle.Functions\<close> in
+ Isabelle/\<^verbatim>\<open>Pure.jar\<close> with the following line in
+ \<^file>\<open>$ISABELLE_HOME/etc/settings\<close>:
+ @{verbatim [display, indent = 2] \<open>isabelle_scala_service 'isabelle.Functions'\<close>}
+
+ The overall list of registered functions is accessible in Isabelle/Scala as
+ \<^scala_object>\<open>isabelle.Scala.functions\<close>.
+\<close>
+
+
+subsection \<open>Invoking functions in Isabelle/ML\<close>
+
+text \<open>
+ Isabelle/PIDE provides a protocol to invoke registered Scala functions in
+ ML: this requires a proper PIDE session context, e.g.\ within the Prover IDE
+ or in batch builds via option @{system_option pide_session}.
+
+ The subsequent ML antiquotations refer to Scala functions in a
+ formally-checked manner.
+
+ \begin{matharray}{rcl}
+ @{ML_antiquotation_def "scala_function"} & : & \<open>ML_antiquotation\<close> \\
+ @{ML_antiquotation_def "scala"} & : & \<open>ML_antiquotation\<close> \\
+ \end{matharray}
+
+ \<^rail>\<open>
+ (@{ML_antiquotation scala_function} | @{ML_antiquotation scala})
+ @{syntax embedded}
+ \<close>
+
+ \<^descr> \<open>@{scala_function name}\<close> inlines the checked function name as ML string
+ literal.
+
+ \<^descr> \<open>@{scala name}\<close> invokes the checked function via the PIDE protocol. In
+ Isabelle/ML this appears as a function of type
+ \<^ML_type>\<open>string -> string\<close>, which is subject to interrupts within the ML
+ runtime environment as usual. A \<^scala>\<open>null\<close> result in Scala raises an
+ exception \<^ML>\<open>Scala.Null\<close> in ML.
+
+ The standard approach of representing datatypes via strings works via XML in
+ YXML transfer syntax. See Isabelle/ML operations and modules @{ML
+ YXML.string_of_body}, @{ML YXML.parse_body}, @{ML_structure XML.Encode},
+ @{ML_structure XML.Decode}; similarly for Isabelle/Scala. Isabelle symbols
+ may have to be recoded via Scala operations
+ \<^scala_method>\<open>isabelle.Symbol.decode\<close> and
+ \<^scala_method>\<open>isabelle.Symbol.encode\<close>.
+\<close>
+
+
+subsubsection \<open>Examples\<close>
+
+text \<open>
+ Invoke a predefined Scala function that is the identity on type
+ \<^ML_type>\<open>string\<close>:
+\<close>
+
+ML \<open>
+ val s = "test";
+ val s' = \<^scala>\<open>echo\<close> s;
+ \<^assert> (s = s')
+\<close>
+
+text \<open>
+ Let the Scala compiler process some toplevel declarations, producing a list
+ of errors:
+\<close>
+
+ML \<open>
+ val source = "class A(a: Int, b: Boolean)"
+ val errors =
+ \<^scala>\<open>scala_toplevel\<close> source
+ |> YXML.parse_body
+ |> let open XML.Decode in list string end;
+
+ \<^assert> (null errors)\<close>
+
+text \<open>
+ The above is merely for demonstration. See \<^ML>\<open>Scala_Compiler.toplevel\<close>
+ for a more convenient version with builtin decoding and treatment of errors.
+\<close>
+
+
+section \<open>Documenting Isabelle/Scala entities\<close>
+
+text \<open>
+ The subsequent document antiquotations help to document Isabelle/Scala
+ entities, with formal checking of names against the Isabelle classpath.
+
+ \begin{matharray}{rcl}
+ @{antiquotation_def "scala"} & : & \<open>antiquotation\<close> \\
+ @{antiquotation_def "scala_object"} & : & \<open>antiquotation\<close> \\
+ @{antiquotation_def "scala_type"} & : & \<open>antiquotation\<close> \\
+ @{antiquotation_def "scala_method"} & : & \<open>antiquotation\<close> \\
+ \end{matharray}
+
+ \<^rail>\<open>
+ (@@{antiquotation scala} | @@{antiquotation scala_object})
+ @{syntax embedded}
+ ;
+ @@{antiquotation scala_type} @{syntax embedded} types
+ ;
+ @@{antiquotation scala_method} class @{syntax embedded} types args
+ ;
+ class: ('(' @'in' @{syntax name} types ')')?
+ ;
+ types: ('[' (@{syntax name} ',' +) ']')?
+ ;
+ args: ('(' (nat | (('_' | @{syntax name}) + ',')) ')')?
+ \<close>
+
+ \<^descr> \<open>@{scala s}\<close> is similar to \<open>@{verbatim s}\<close>, but the given source text is
+ checked by the Scala compiler as toplevel declaration (without evaluation).
+ This allows to write Isabelle/Scala examples that are statically checked.
+
+ \<^descr> \<open>@{scala_object x}\<close> checks the given Scala object name (simple value or
+ ground module) and prints the result verbatim.
+
+ \<^descr> \<open>@{scala_type T[A]}\<close> checks the given Scala type name (with optional type
+ parameters) and prints the result verbatim.
+
+ \<^descr> \<open>@{scala_method (in c[A]) m[B](n)}\<close> checks the given Scala method \<open>m\<close> in
+ the context of class \<open>c\<close>. The method argument slots are either specified by
+ a number \<open>n\<close> or by a list of (optional) argument types; this may refer to
+ type variables specified for the class or method: \<open>A\<close> or \<open>B\<close> above.
+
+ Everything except for the method name \<open>m\<close> is optional. The absence of the
+ class context means that this is a static method. The absence of arguments
+ with types means that the method can be determined uniquely as \<^verbatim>\<open>(\<close>\<open>m\<close>\<^verbatim>\<open> _)\<close>
+ in Scala (no overloading).
+\<close>
+
+
+subsubsection \<open>Examples\<close>
+
+text \<open>
+ Miscellaneous Isabelle/Scala entities:
+
+ \<^item> object: \<^scala_object>\<open>isabelle.Isabelle_Process\<close>
+ \<^item> type without parameter: @{scala_type isabelle.Console_Progress}
+ \<^item> type with parameter: @{scala_type List[A]}
+ \<^item> static method: \<^scala_method>\<open>isabelle.Isabelle_System.bash\<close>
+ \<^item> class and method with type parameters:
+ @{scala_method (in List[A]) map[B]("A => B")}
+ \<^item> overloaded method with argument type: @{scala_method (in Int) "+" (Int)}
+\<close>
+
end