(* Title: HOL/Code_Evaluation.thy
Author: Florian Haftmann, TU Muenchen
*)
header {* Term evaluation using the generic code generator *}
theory Code_Evaluation
imports Typerep Limited_Sequence
keywords "value" :: diag
begin
subsection {* Term representation *}
subsubsection {* Terms and class @{text term_of} *}
datatype "term" = dummy_term
definition Const :: "String.literal \<Rightarrow> typerep \<Rightarrow> term" where
"Const _ _ = dummy_term"
definition App :: "term \<Rightarrow> term \<Rightarrow> term" where
"App _ _ = dummy_term"
definition Abs :: "String.literal \<Rightarrow> typerep \<Rightarrow> term \<Rightarrow> term" where
"Abs _ _ _ = dummy_term"
definition Free :: "String.literal \<Rightarrow> typerep \<Rightarrow> term" where
"Free _ _ = dummy_term"
code_datatype Const App Abs Free
class term_of = typerep +
fixes term_of :: "'a \<Rightarrow> term"
lemma term_of_anything: "term_of x \<equiv> t"
by (rule eq_reflection) (cases "term_of x", cases t, simp)
definition valapp :: "('a \<Rightarrow> 'b) \<times> (unit \<Rightarrow> term)
\<Rightarrow> 'a \<times> (unit \<Rightarrow> term) \<Rightarrow> 'b \<times> (unit \<Rightarrow> term)" where
"valapp f x = (fst f (fst x), \<lambda>u. App (snd f ()) (snd x ()))"
lemma valapp_code [code, code_unfold]:
"valapp (f, tf) (x, tx) = (f x, \<lambda>u. App (tf ()) (tx ()))"
by (simp only: valapp_def fst_conv snd_conv)
subsubsection {* Syntax *}
definition termify :: "'a \<Rightarrow> term" where
[code del]: "termify x = dummy_term"
abbreviation valtermify :: "'a \<Rightarrow> 'a \<times> (unit \<Rightarrow> term)" where
"valtermify x \<equiv> (x, \<lambda>u. termify x)"
locale term_syntax
begin
notation App (infixl "<\<cdot>>" 70)
and valapp (infixl "{\<cdot>}" 70)
end
interpretation term_syntax .
no_notation App (infixl "<\<cdot>>" 70)
and valapp (infixl "{\<cdot>}" 70)
subsection {* Tools setup and evaluation *}
lemma eq_eq_TrueD:
assumes "(x \<equiv> y) \<equiv> Trueprop True"
shows "x \<equiv> y"
using assms by simp
ML_file "Tools/code_evaluation.ML"
code_reserved Eval Code_Evaluation
subsection {* @{text term_of} instances *}
instantiation "fun" :: (typerep, typerep) term_of
begin
definition
"term_of (f \<Colon> 'a \<Rightarrow> 'b) =
Const (STR ''Pure.dummy_pattern'')
(Typerep.Typerep (STR ''fun'') [Typerep.typerep TYPE('a), Typerep.typerep TYPE('b)])"
instance ..
end
instantiation String.literal :: term_of
begin
definition
"term_of s = App (Const (STR ''STR'')
(Typerep.Typerep (STR ''fun'') [Typerep.Typerep (STR ''list'') [Typerep.Typerep (STR ''char'') []],
Typerep.Typerep (STR ''String.literal'') []])) (term_of (String.explode s))"
instance ..
end
subsubsection {* Code generator setup *}
declare [[code drop: rec_term case_term size_term "size :: term \<Rightarrow> _" "HOL.equal :: term \<Rightarrow> _"
"term_of :: typerep \<Rightarrow> _" "term_of :: term \<Rightarrow> _" "term_of :: String.literal \<Rightarrow> _"
"term_of :: _ Predicate.pred \<Rightarrow> term" "term_of :: _ Predicate.seq \<Rightarrow> term"]]
lemma term_of_char [unfolded typerep_fun_def typerep_char_def typerep_nibble_def, code]:
"Code_Evaluation.term_of c = (case c of Char x y \<Rightarrow>
Code_Evaluation.App (Code_Evaluation.App
(Code_Evaluation.Const (STR ''String.char.Char'') (TYPEREP(nibble \<Rightarrow> nibble \<Rightarrow> char)))
(Code_Evaluation.term_of x)) (Code_Evaluation.term_of y))"
by (subst term_of_anything) rule
code_printing
type_constructor "term" \<rightharpoonup> (Eval) "Term.term"
| constant Const \<rightharpoonup> (Eval) "Term.Const/ ((_), (_))"
| constant App \<rightharpoonup> (Eval) "Term.$/ ((_), (_))"
| constant Abs \<rightharpoonup> (Eval) "Term.Abs/ ((_), (_), (_))"
| constant Free \<rightharpoonup> (Eval) "Term.Free/ ((_), (_))"
| constant "term_of \<Colon> integer \<Rightarrow> term" \<rightharpoonup> (Eval) "HOLogic.mk'_number/ HOLogic.code'_integerT"
| constant "term_of \<Colon> String.literal \<Rightarrow> term" \<rightharpoonup> (Eval) "HOLogic.mk'_literal"
code_reserved Eval HOLogic
subsubsection {* Obfuscation *}
print_translation {*
let
val term = Const ("<TERM>", dummyT);
fun tr1' _ [_, _] = term;
fun tr2' _ [] = term;
in
[(@{const_syntax Const}, tr1'),
(@{const_syntax App}, tr1'),
(@{const_syntax dummy_term}, tr2')]
end
*}
subsection {* Diagnostic *}
definition tracing :: "String.literal \<Rightarrow> 'a \<Rightarrow> 'a" where
[code del]: "tracing s x = x"
code_printing
constant "tracing :: String.literal => 'a => 'a" \<rightharpoonup> (Eval) "Code'_Evaluation.tracing"
subsection {* Interactive evaluation *}
ML_file "~~/src/HOL/Tools/value.ML"
subsection {* Generic reification *}
ML_file "~~/src/HOL/Tools/reification.ML"
hide_const dummy_term valapp
hide_const (open) Const App Abs Free termify valtermify term_of tracing
end