(* Title: HOL/Library/ExecutableRat.thy
ID: $Id$
Author: Florian Haftmann, TU Muenchen
*)
header {* Simple example for executable rational numbers *}
theory Codegenerator_Rat
imports ExecutableRat EfficientNat
begin
definition
foo :: "rat \<Rightarrow> rat \<Rightarrow> rat \<Rightarrow> rat" where
"foo r s t = (t + s) / t"
definition
bar :: "rat \<Rightarrow> rat \<Rightarrow> rat \<Rightarrow> bool" where
"bar r s t \<longleftrightarrow> (r - s) \<le> t \<or> (s - t) \<le> r"
definition
"R1 = Fract 3 7"
definition
"R2 = Fract (-7) 5"
definition
"R3 = Fract 11 (-9)"
definition
"foobar = (foo R1 1 R3, bar R2 0 R3, foo R1 R3 R2)"
code_gen foobar in SML in OCaml file - in Haskell file -
ML {* ROOT.Codegenerator_Rat.foobar *}
code_module Foo
contains foobar
ML {* Foo.foobar *}
end