header {* Futures and parallel lists for code generated towards Isabelle/ML *}
theory Parallel
imports Main
begin
subsection {* Futures *}
datatype 'a future = fork "unit => 'a"
primrec join :: "'a future => '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_type future
(Eval "_ future")
code_const fork
(Eval "Future.fork")
code_const join
(Eval "Future.join")
code_reserved Eval Future future
subsection {* Parallel lists *}
definition map :: "('a => 'b) => 'a list => 'b list" where
[simp]: "map = List.map"
definition forall :: "('a => bool) => 'a list => bool" where
"forall = list_all"
lemma forall_all [simp]:
"forall P xs <-> (∀x∈set xs. P x)"
by (simp add: forall_def list_all_iff)
definition exists :: "('a => bool) => 'a list => bool" where
"exists = list_ex"
lemma exists_ex [simp]:
"exists P xs <-> (∃x∈set xs. P x)"
by (simp add: exists_def list_ex_iff)
code_const map
(Eval "Par'_List.map")
code_const forall
(Eval "Par'_List.forall")
code_const exists
(Eval "Par'_List.exists")
code_reserved Eval Par_List
hide_const (open) fork join map exists forall
end