(* Author: Florian Haftmann, TU Muenchen *)
section \<open>Futures and parallel lists for code generated towards Isabelle/ML\<close>
theory Parallel
imports Main
begin
subsection \<open>Futures\<close>
datatype 'a future = fork "unit \<Rightarrow> 'a"
primrec join :: "'a future \<Rightarrow> 'a" where
"join (fork f) = f ()"
lemma future_eqI [intro!]:
assumes "join f = join g"
shows "f = g"
using assms by (cases f, cases g) (simp add: ext)
code_printing
type_constructor future \<rightharpoonup> (Eval) "_ future"
| constant fork \<rightharpoonup> (Eval) "Future.fork"
| constant join \<rightharpoonup> (Eval) "Future.join"
code_reserved (Eval) Future future
subsection \<open>Parallel lists\<close>
definition map :: "('a \<Rightarrow> 'b) \<Rightarrow> 'a list \<Rightarrow> 'b list" where
[simp]: "map = List.map"
definition forall :: "('a \<Rightarrow> bool) \<Rightarrow> 'a list \<Rightarrow> bool" where
"forall = list_all"
lemma forall_all [simp]:
"forall P xs \<longleftrightarrow> (\<forall>x\<in>set xs. P x)"
by (simp add: forall_def list_all_iff)
definition exists :: "('a \<Rightarrow> bool) \<Rightarrow> 'a list \<Rightarrow> bool" where
"exists = list_ex"
lemma exists_ex [simp]:
"exists P xs \<longleftrightarrow> (\<exists>x\<in>set xs. P x)"
by (simp add: exists_def list_ex_iff)
code_printing
constant map \<rightharpoonup> (Eval) "Par'_List.map"
| constant forall \<rightharpoonup> (Eval) "Par'_List.forall"
| constant exists \<rightharpoonup> (Eval) "Par'_List.exists"
code_reserved (Eval) Par_List
hide_const (open) fork join map exists forall
end