(* Title: Tools/SML/Examples.thy
Author: Makarius
*)
section \<open>Standard ML within the Isabelle environment\<close>
theory Examples
imports Pure
begin
text \<open>
Isabelle/ML is a somewhat augmented version of Standard ML, with various
add-ons that are indispensable for Isabelle development, but may cause
conflicts with independent projects in plain Standard ML.
The Isabelle/Isar command \<^theory_text>\<open>SML_file\<close> supports official Standard ML within
the Isabelle environment, with full support in the Prover IDE
(Isabelle/jEdit).
Here is a very basic example that defines the factorial function and
evaluates it for some arguments.
\<close>
SML_file \<open>factorial.sml\<close>
text \<open>
The subsequent example illustrates the use of multiple \<^theory_text>\<open>SML_file\<close> commands
to build larger Standard ML projects. The toplevel SML environment is
enriched cumulatively within the theory context of Isabelle ---
independently of the Isabelle/ML environment.
\<close>
SML_file \<open>Example.sig\<close>
SML_file \<open>Example.sml\<close>
text \<open>
Isabelle/ML and SML share a common run-time system, but the static
environments are separate. It is possible to exchange toplevel bindings via
separate commands like this.
\<close>
SML_export \<open>val f = factorial\<close> \<comment> \<open>re-use factorial from SML environment\<close>
ML \<open>f 42\<close>
SML_import \<open>val println = Output.writeln\<close>
\<comment> \<open>re-use Isabelle/ML channel for SML\<close>
SML_import \<open>val par_map = Par_List.map\<close>
\<comment> \<open>re-use Isabelle/ML parallel list combinator for SML\<close>
end